I thought they where neither? ...that they, "were" mV but they got multiplied by the ADC. By my understanding they are an undefined unit of measurement (Not as much a ft and what not).
Dylan,
As I understand it the ADC (Analog-to-Digital Converter) does just that: it changes the analog signal from the CO2 sensor in digital numbers (0's and 1's) then ultimately into ppm numbers when the correct algorithm (an equation, or a multiplied value) is added into the program.
Andrew, Sylvie , or Dr. Allen, can you explain analog-to-digitala conversion simply? I don't want to misinform the Rocketeers...
2) HIGH 3 was on
3) TP1 to CH0, to 3 to CH1
4) ALM to p3 and CNTL (HSW) to p4
There is an inconsistency there. If CNTL is connected to p4, then HIGH 4 should be on, not HIGH 3. If CNTL is in fact connected to p4 and p4 is floating (not commanded to be either HIGH or LOW), then you could expect dicey results. But the fact that the heater is on suggests that the CO2 sensor is in fact active.
Dylan said...
I thought they where neither? They, "were" mV but they got multiplied by the ADC. By my understanding they are an undefined unit of measurement (Not as much a ft and what not). Am I on the right path? Or the wrong one? Unless the formula was taken out and I missed something. Then it would be mV.
The MCP3202 ADC uses a technique called successive approximation. It takes 12 steps and makes 12 comparisons. It goes like this.
1) Is the signal greater than than 1/2 the power supply voltage? Yes=1 No=0. That is the most significant bit.
2) If the result in step 1 was Yes=1, then, is the signal greater than 3/4 the power supply? Yes=1, No=0
If the result in step 1 was No=0, then, is the signal greater than 1/4 the power supply? Yes=1, No=0
That is the second most significant bit.
3..) The same process continues for 10 more steps, each time choosing to branch up or down depending on the previous result.
It branches up for a 1 and down for a zero, and at each branch it narrows down the window around the signal...
The final result is a pattern of zeros and ones that are the pattern of branching comparisons that zoom in on the signal
Internally it is adding up the weights of each bit, as follows
2048..1024..512..256..128..64..32..16..8..4..2..1
It adds the weight if the bit is 1, and adds zero if the bit is zero.
For example, CO2pp=101010101010 means up,down,up,down
2048 + 512 + 128 + 32 + 8. + 2 =
Homework: add up the numbers
Homework: What is the sum for this binary number? 110011101111
Internally the process is a lot simpler than it sounds. It is a very clever but dumb decision making circuit inside that little chip.
The final number that comes out of the ADC is a proportion of the power supply voltage as the reference. So if the power supply is 5000 mV, the program has to multiply by 5000/4096 = 1.2207 in order to convert the ADC result to mV. The conversion to ppm will be another step.
Baseball is going great. I play 2nd base, I can catch, and sometimes on the town team (WAC) I play first. We are 4-4. Today is my first playoff game for WAC, and if we win this game we goto the championship game on saturday. For the highschool summer league team, we are 4-2 and I play either 2nd base or right field.
Dr.Allen,
The MCP3202 ADC's "successive approximation", this is something that is built into the chip, right?
Sean,
Yes, the successive approximation is built into the chip.
I'm glad to know you are doing baseball. I enjoy baseball myself too, at least watching it. Here in the SF bay area we have the A's and the Giants. I follow them both. I'll be in Chicago for the 4th, home of the Cubs and the White Sox, another cross town rivalry. After the 4th my wife and I will head up to my sister's house on Lake Michigan for a couple of days. They live right on the lake.
I'm attaching a variation on the 27929 CO2 sensor DEMO program, the one I've been using to test the CO2 sensor using the same pins as I think are used in the ASP-2 program.
The MCP3202 ADC uses a technique called successive approximation. It takes 12 steps and makes 12 comparisons. It goes like this.
1) Is the signal greater than than 1/2 the power supply voltage? Yes=1 No=0. That is the most significant bit.
2) If the result in step 1 was Yes=1, then, is the signal greater than 3/4 the power supply? Yes=1, No=0
If the result in step 1 was No=0, then, is the signal greater than 1/4 the power supply? Yes=1, No=0
That is the second most significant bit.
3..) The same process continues for 10 more steps, each time choosing to branch up or down depending on the previous result.
It branches up for a 1 and down for a zero, and at each branch it narrows down the window around the signal...
The final result is a pattern of zeros and ones that are the pattern of branching comparisons that zoom in on the signal
Internally it is adding up the weights of each bit, as follows
2048..1024..512..256..128..64..32..16..8..4..2..1
It adds the weight if the bit is 1, and adds zero if the bit is zero.
For example, CO2pp=101010101010 means up,down,up,down
2048 + 512 + 128 + 32 + 8. + 2 =
Homework: add up the numbers
Homework: What is the sum for this binary number? 110011101111
Internally the process is a lot simpler than it sounds. It is a very clever but dumb decision making circuit inside that little chip.
The final number that comes out of the ADC is a proportion of the power supply voltage as the reference. So if the power supply is 5000 mV, the program has to multiply by 5000/4096 = 1.2207 in order to convert the ADC result to mV. The conversion to ppm will be another step.
Hmm. It seems to me that a clever person with some mechanical aptitude could build a analog-to-digital mechanical scale that used that kind of algorithm, with nothing but balances (that is, no electronics). Having seen the Turing machine and the wooden nickle maker at the Chicago Prop Expo back in May, I have no doubt someone has those skills - probably someone right here on the Parallax forums.
==================
I went to a minor league game in Beloit last night, the Twins' Midwest League Class A affiliate. The big surprise was that the Beloit Snappers' starting shortstop and leadoff hitter was none other than JJ Hardy, longtime Brewer and current Twins major-leaguer, who was in a Beloit on a three-day rehab assignment. It was good to see him, though he took the collar in 3 ABs.
The fun "minor league atmosphere" part of the game came right after the final out in the Snappers' loss: some elderly guy down the first base line shouted "Dagnabbit!".
==================
ARLISS content:·· (* You probably do not need any of this for your project - it's just thought exercises *)
Notice that the Alarm function has only two possible values: on and off. You could use a Byte-sized variable to represent whether or not the alarm was on, but you'd only be using one bit of that entire 8-bit variable. The possible values of the variable would be
Off -00000000
On·-00000001
Suppose you had another sensor that also had an alarm function. You could have a Byte-sized variable for that alarm as well, or you could code the two alarms into one variable:
You can see that you could have up to eight "on - off" variables held in that one byte, which would save you up to seven bytes' worth of variable space compared with a program that used one Byte-sized variable for each of the 8 alarms.
If you had two sensors each of which had 16 possible values, you could still code both in one Byte-sized variable:
and so on. This is where it's sometimes nice to use hexadecimal (base 16), because then you get a two-digit number where each digit tells you the value of one of the two variables held in that one byte:
Tracy Allen said... "There is an inconsistency there. If CNTL is connected to p4, then HIGH 4 should be on, not HIGH 3. If CNTL is in fact connected to p4 and p4 is floating (not commanded to be either HIGH or LOW), then you could expect dicey results. But the fact that the heater is on suggests that the CO2 sensor is in fact active."
2) HIGH 3 was on
3) TP1 to CH0, to 3 to CH1
4) ALM to p3 and CNTL (HSW) to p4
My mistake. It was a simple typo, that's all. I meant HIGH 4, not HIGH 3.
We've had the ASP-BOE running for nearly three hours WITH HIGH 4 'OFF' (commented out) and we a couple of observations:
1) Yes, it does take the CO2 sensor (is heater active?) quite a while to warm up and then stabilzie to amibient conditions (45 minutes or so.)
2) The metal CO2 sensor is NOT HOT after 2 hours. Conclusion: the heater is, in fact, "OFF"
3) Once it's 'warmed up' (with HIGH 4 off??) and stable, the data fluctuations stabilized are less. Put another way, there's a narrower range between the highest and lowest readings during that particular 4-5 minute phase/point in time.
4) When we graphed the data earlier (for a shorter 1-1/2 hour 'trial') the graph looked a lot like the one you posted... hmmm. Curious.
I (and we, the Rocketeers!) enjoyed the expalanation of "successive approximation." It was sure interesting and it generated a lot of 'back channel chatter" by e-mail. They're working on the answers to the questions you posted as we "speak'.
======================================
I have to run Christopher to work and I'll post the lastest graph when I return. He's a "Flood Plain Ranger" at the Society for the Protection of New Hamsphire Fores and he patrols the trails and does trail work. Good summer job for a good kid.
The attached two graphs have self-explanatory text beneath. We're still trying to figure this glitch out. We must have it wired wrong somewhere... We've looked under the hood and in the trunk but we'll stick with it and report back. This HIGH 4 thing is an interesting mystery, better than any cryptoquote puzzle. When we solve HIGH 4 we'll hope for a "high 5!"
"I'm attaching a variation on the 27929 CO2 sensor DEMO program, the one I've been using to test the CO2 sensor using the same pins as I think are used in the ASP-2 program."
Thanks Tracy. I'm running the modified demo program right now. Mostly 0's in the ADC0 column but it's only been running for 5 minutes. The heater may need to heat up so I'll wait a while and see what happens. I have a hunch that it's something in the wiring at this end. But nothing looks awry. Eventually it will prove to be something simple (and probably silly.) But silly is good.
=====================================
Will you get to see a Cubs or White Sox game while you're in Chicago? Or will you track down another Turing machine and the wooden nickle maker? Come to think of it, the Fermi Lab and the Field Museum are also there.... lots of possibilities!
You said, " I have no doubt someone has those skills (devising another Turing machine v.2) - probably someone right here on the Parallax forums." I like to believe that you, Sylvie and I are giving that spark of interest and curiosity to some bright young mind, our Rocketeers. You can never really quantify what a kid learns (I'd like to do away with that artifice called 'grades' altogether) and you never know where knowledge and imagination will lead someone. That's the beauty, isn't it? One of these tykes might invent something that we could never conceive nor imagine.
=====================================
15 minutes into the demo program and still getting mostly 0's.
Homework: add up the numbers
Homework: What is the sum for this binary number? 110011101111
Dr. Allen,
Here are the answers to your recent homework questions. Our team discussed them thoroughly via e-mail earlier today, and I believe they are correct.
Homework question 1: 2048 + 512 + 128 + 32 + 8 + 2 = 2730 Homework question 2: We might not be interpreting the term "sum" correctly in this case, but we believe you are asking what the binary value equals. In this case, 110011101111 has a decimal value of 3311. I used a special calculator to get this value, and Dylan received the same number using his own method. Is this correct?
Thank you,
Andrew
Post Edited (Andrew (ARLISS)) : 7/2/2010 1:53:17 AM GMT
You are right about the this being the same as what the binary value equals.
Here is the last one with all the zeros and ones written out:
2048*1 + 1024*1 + 512*0 + 256*0 + 128*1 + 64*1 + 32*1 + 8*1 + 4*1 + 2*1 + 1*1 = 3311
See the powers of two, and the binary 110011101111?
That last form is called a polynomial. Have you heard that term? That is how mathematicians think of positional numbers, like binary (base 2) 101010101010 or decimal (base 10) 1234567 or hex (base 16) $F17A. Positional number systems are shorthand for polynomials.
Mark said...
I'm running the modified demo program right now. Mostly 0's in the ADC0 column but it's only been running for 5 minutes. The heater may need to heat up so I'll wait a while and see what happens. I have a hunch that it's something in the wiring at this end. But nothing looks awry. Eventually it will prove to be something simple (and probably silly.) But silly is good.
I'm also looking at the graphs from the 4.5 hour test, you posted at 1:55pm. There does seem to be some glitch in the workings and you will probably say, "aha!" or "huh?!" or "duh!" when you find it. You're looking for something like a Ground wire that isn't quite connected. Wires can be off by one connection point, or a wire is broken or doesn't make good contact. The CO2 reading should not be zero, even near the beginning of a run.
Excellent work on getting your homework done and collaborating with Andrew by e-mail to cross-check your answers. You really are coming together nicely as a team. Speaking of which, it looks like Mike will be·making the trip to Nevada with us! All five of you together to stretch our budget but Mike will be joining us. I'll ask for a really BIG room...!
Tracy, Sylvie, and Rocketeers--
·· I think I may have fried the BOE, stamp, ADC, or (likely?) the CO2 module <
it was really (REALLY) hot at one point. I'm not sure·exactly what happened·and I'm backtracking·and troubleshooting from square one. I agree that it will probably·prove to be·something simple and silly.
=====================================
After running the ASP-BOE clone successfully for hours, just when it looked like we were "so close" with the program.... things stopped working!!··
The bottom line is, I got repeated "No Stamp recognized" error messages. The program would try to initialize and then a "No Stamp recognized" error message appeared, repeatedly. Sometimes it wouldn't even try to initialize and I would get the error message instantly. Was the circuitry overheating after running for·hours (and off and on for days?)
==============================
Christopher and I rebuilt/ rewired a third ASP-BOE clone (with·components from our spare parts box, not from the "fried" ASP-BOE), etc., etc. and the same thing happened.·We tried all the logical fixes-- switched the serial input cable, ran a different program, switched out the BASIC stamps, CO2 sensor module, ADC chip, resistors, etc., with similar results. This happened late in the evening and·we had·been working·on it off and on all·day.·Chris went to work at 4 and I puttered with it until he got home at 9, then until midnight after he went to bed. So maybe I was just tired.
I'm sure Tracy, that it'll prove to be something simple like you said. In the mean time I'll build two·more ASP-BOE clones and order·all the requisite extra parts from Parallax "just in case" I toasted some circuitry.
I'm in Maine now, then back to New Hampshire, then out if state for a few weeks. I have my ASP-BOE travel kit already packed. I really enjoy figuring things like this out... better than any good mystery novel!
Hi rocketeers, Please don't let CO2 measurement problems cloud your vacation. Banish Murphy's law from your thoughts! You will get it working all in good time. I'm heading off for Chicago this afternoon and as usual will carry along a Stamp and a Propeller with a few attachments. But I don't expect to do much with them. Sometimes I have to answer urgent technical question while I am away from the business, but I hope not too much. Maybe I'll take along the CO2 sensor and set it up next to Lake Michigan.
I have a little analogy that I'll develop to explain the connection between ppm ("parts per milllion") and pp ("partial pressure").
-- What is your understanding of the difference between those two terms, and as they apply to your CO2 measurements as the ASP-2 heads up and up and down again?
-- Also, would you prefer an analogy in terms of a soccer field, or bumper cars?
The world cup Germany-Argentina game was really something. Talk about teamwork and precision footwork on the part of the Germans. Alemania, as we were watching on Spanish language TV.
Hi rocketeers, Please don't let CO2 measurement problems cloud your vacation. Banish Murphy's law from your thoughts!
Tracy,
·· Consider Murphy (and his law) banished (or rather, exorcised.)·The ASP-BOE is purring away, cranking out near-perfect millivoltage and CO2 "data," After·troubleshooting for a little while, Christopher, Bandit the Rocket Dog, and I have concluded·that it was simply loose wires. Nothing more!··
Now I understand why you suggested that we to solder the wires to perfboard... advice that is now·well underdstood and well taken, and another excellent·lesson learned (in retrospect we were lucky that last year's ASP-BOE didn't fall victim to·loose wire during one of its two high-G, high-altitude flights. Now that the problem is solved we'll retire the ASP-BOE for the rest of the long holiday weekend.
++++++++++++++++++++++++++++++++++++++++
So you're off on your adventure to the Windy City, yes? I hope you have a fun and relaxing time with your family and friends. Be safe, too. I'm eager to hear all about the things you'll see and do in Chicago. I hope no particles come flying off of the Fermi Lab Particle Accelerator while you're there (the folks ast the rental car company don't appreciate holes in the side of their new cars.
++++++++++++++++++++++++++++++++++++++++
Time to put charcoal on the grill· and take the sea kayaks out (and put the gadgetry away.) Our summer cottage is the red and green Victorian on the right in the attached picture and there's plenty of daylight left. You and Sylvie are welcome to come any time... for a day, a week, or a summer. It's in Orr's Island, Maine, about 12 miles from Bowdoin College. Take care, have fun, and
Hi rocketeers, Please don't let CO2 measurement problems cloud your vacation. Banish Murphy's law from your thoughts!
Tracy,
·· Consider Murphy (and his law) banished (or rather, exorcised.)·The ASP-BOE is purring away, cranking out near-perfect millivoltage and CO2 "data," After·troubleshooting for a little while, Christopher, Bandit the Rocket Dog, and I have concluded·that it was simply loose wires. Nothing more!··
···Now I understand why you suggested that we to solder the wires to perfboard... advice that is now·well underdstood and well taken, and another excellent·lesson learned (in retrospect we were lucky that last year's ASP-BOE didn't fall victim to·loose wire during one of its two high-G, high-altitude flights. Now that the problem is solved we'll retire the ASP-BOE for the rest of the long holiday weekend.
++++++++++++++++++++++++++++++++++++++++
So you're off on your adventure to the Windy City, yes? I hope you have a fun and relaxing time with your family and friends. Be safe, too. I'm eager to hear all about the things you'll see and do in Chicago. I hope no particles come flying off of the Fermi Lab Particle Accelerator while you're there (the folks ast the rental car company don't appreciate holes in the side of their new cars.
++++++++++++++++++++++++++++++++++++++++
Time to put charcoal on the grill· and take the sea kayaks out (and put the gadgetry away.) Our summer cottage is the red and green Victorian on the right in the attached picture and there's plenty of daylight left. You and Sylvie are welcome to come any time... for a day, a week, or a summer. It's in Orr's Island, Maine, about 12 miles from Bowdoin College. Take care, have fun, and
Um, wow. It's beautiful.
Great biking around here the last few days, and while I didn't watch Germany play, I did see the Spain-Paraguay match. · Very nice ball handling there as well. Sorry, Deutschland fans, but Go Espana!
I don't think you can expect a reliable device in a rocket with connections that aren't soldered. You're pulling double-digit G forces under power, and probably even higher forces when the ejection charges go off. Things have to be mounted very solidly. I flew an SD card datalogger a few times, but eventually gave up because the SD card kept popping out of the socket when the ejection charge went off.
Happy 4th of July (almost.) So when do you want to come to Maine? We'll go sea kayaing, sailboating, or fishing for mackerel (Holy Mackerel!) The when we get back we'll all have lobster, fresh from the lobster pound* across the bridge (*it's like a dog pound, but for lobsters I guess.)
So where did you go biking? Do you mountain bike or·ride the roads? Be careful wherever you ride and be sure to wear your helmet. Remember Susanne's horrific bicycling accident last October? Her helmet literally saved her life. When the car hit her from behind she was catapulted head first into a tree. It was a terrible accident but·I think it would have been much worse if she hadn't been wearing her helmet.
What are you plans for the 4th? A baseball game? Pyrotechnics? Watching World Cup Soccer? I've lost track of who's·still in it...! I take it Germany, Spain, and Paraguay are still in? It most be getting close to the·Final Four (do they call it that?)· A friend of ours and her daughter are both soccer officials and they've been glued to the TV watching the World Cup (not literally of course. That would be messy and make it hard to see the game.) They're from New Zealand and they're rabid about 'football'. I get corrected every time I call it 'soccer'. "Sacrilege!", Chantal says. I should look up the meaning of 'sacrilege.' It must mean "You rock!" or soemthing like that because she says it with such emphasis.
The *original* ASP-BOE-MAWD works perfectly now and it cranks out mV and CO2 data almost flawless (temperature, humidity, too...!) Thank you Tracy and Paul!·I admire and envy your knowledge and skills, and I also learning lots this·year, probably more than ever.·But we can't seem to get the two clones to work nearly as well as ASP-1. Maybe it's the wiring or maybe it's because we don't have a MAWD wired to the clones, or both.Would the MAWD not·being·wired to the BOE affect the clones so much (erratic data, wide data range, corrupt data on the flash drive)?·In any event the original ASP-BOE is working really, really·well right now. But we ought to have a back-up·"just in case", and·more importantly we ought to be able to answer the question·"Why?" As you know, rocketry and computer programming are very existential (but I don't know "why"...)
Happy 4th of July (almost.) So when do you want to come to Maine? We'll go sea kayaing, sailboating, or fishing for mackerel (Holy Mackerel!) The when we get back we'll all have lobster, fresh from the lobster pound* across the bridge (*it's like a dog pound, but for lobsters I guess.)
So where did you go biking? Do you mountain bike or·ride the roads? Be careful wherever you ride and be sure to wear your helmet. Remember Susanne's horrific bicycling accident last October? Her helmet literally saved her life. When the car hit her from behind she was catapulted head first into a tree. It was a terrible accident but·I think it would have been much worse if she hadn't been wearing her helmet.
What are you plans for the 4th? A baseball game? Pyrotechnics? Watching World Cup Soccer? I've lost track of who's·still in it...! I take it Germany, Spain, and Paraguay are still in? It most be getting close to the·Final Four (do they call it that?)· A friend of ours and her daughter are both soccer officials and they've been glued to the TV watching the World Cup (not literally of course. That would be messy and make it hard to see the game.) They're from New Zealand and they're rabid about 'football'. I get corrected every time I call it 'soccer'. "Sacrilege!", Chantal says. I should look up the meaning of 'sacrilege.' It must mean "You rock!" or soemthing like that because she says it with such emphasis.
The *original* ASP-BOE-MAWD works perfectly now and it cranks out mV and CO2 data almost flawless (temperature, humidity, too...!) Thank you Tracy and Paul!·I admire and envy your knowledge and skills, and I also learning lots this·year, probably more than ever.·But we can't seem to get the two clones to work nearly as well as ASP-1. Maybe it's the wiring or maybe it's because we don't have a MAWD wired to the clones, or both.Would the MAWD not·being·wired to the BOE affect the clones so much (erratic data, wide data range, corrupt data on the flash drive)?·In any event the original ASP-BOE is working really, really·well right now. But we ought to have a back-up·"just in case", and·more importantly we ought to be able to answer the question·"Why?" As you know, rocketry and computer programming are very existential (but I don't know "why"..
Man, I'd love to come to Maine for some sailing. Or kayaking. I'm hoping to go kayaking on the Wisconsin River this coming Friday, if the weather permits.
I ride my bike on bike trails, mostly rails-to-trails. I have to admit that I do not wear a helmet. Yes, I know. Really, yes, I know.
I don't really plan much for tomorrow. Today after the Spain-Paraguay match, I attended my first Tour de Fat (Google it!). It was like the Field of Dreams, a Grateful Dead concert, and the 4th of July all wrapped up into one event.
The remaining World Cup teams are Germany, Spain, the Netherlands, and Uruguay. I've never been to Uruguay, so I guess I'll be terribly disappointed if they win it: Spain is my first choice, of course. Wow, the play in that game today was SO much better than in either of the France matches I watched. The goaltenders were unbelievable.
===================
So are you saying that the ASP-BOE-MAWD is giving you mV data from the CO2 sensor that match the voltage on TP1? (when you measure it with the voltmeter?) That's the real test, I think, of the CO2 sensor hookup. I believe you still need to work out how you're going to convert the voltage reading to CO2 content, and that Tracy has some plans for getting you through that.
I can't see any reason why not having a MAWD hooked up should affect the rest of the system - except that if the program is looking for altitude data and not getting them, it may be trying to put random junk on the screen and into the output to the USB drive. That's a programming issue, and therefore one you should take up with Tracy: the question is "what happens when the program runs on a BoE that doesn't receive any altitude data?". It'll be important to consider that because as you'll remember, before takeoff and during the first 160 feet of flight, you won't get any altitude data, and you need to have a program that can handle that fact.
sylvie369 said...I don't really plan much for tomorrow. Today after the Spain-Paraguay match, I attended my first Tour de Fat (Google it!). It was like the Field of Dreams, a Grateful Dead concert, and the 4th of July all wrapped up into one event.
Tour de Fat sounds like everything you descibe it to be and a bit more, like Woodstock on espresso and chocolate. I don't think I'd be inclined to ride though. I'd probably·just want to enjoy the scenery and ambiance (if that's the right word.) Or do people ride along in capes and tuxedos to some pre-destined finish line, then celebrate? It sound like quite the event!
I just got in from snorkeling with Susanne, Christopher, Bandit the Rocket Dog (sans snorkel), Lenora, and Tim. We saw a gigantic horseshoe crab, bigger than a bushel basket. The folks at the cottage next door are having their annual "spud gun" event. One guy even has a Gattling spud gun! They tether helium balloons in the water and then shoot potatoes at them... lots of well-fed crabs and lobsters today! They (the neighbors, not the lobsters) even have spud gun trophies made up for the event. Then they have a barbecue, beans, and lobster. The folks at the other cottage are having a down-home Maine clam bake right on the beach. Fun on the shores of Maine today. You outta come visit (caveat: not everyone is a techhie or as silly as the·neighbors and I. Lots of stoic Mainers around, too. Hurrah for stoicism!)
For those of you still awake, you should consider tuning to the Science channel where this year's Large Dangerous Rocket Ships (LDRS 29) coverage is being aired. There are some really big and fast rockets, that make even our ARLISS rocket seem small.
E-mail sent to the Team on July 7th in reply to Andrew's and Dylan's e-mails:
Andrew and Rocketeers,
·· Hello from hot and humid Ohio (with emphasis on both hot, and humid·····.) How are things where you are (Florida, New Hampshire, Brazil...?!) It's hard to believe we're headed into the second week of July already.
I worked on the ASP-2 both nights in the hotel traveling out here and it (the original ASP) is working quite well. I'll post·the·graphs and raw data·once I transfer it from the other computer.·I still need to figure out the wiring on my clone because it's not working right. The program is cranking out solid data and the ASP-2 is performming predictably. Now we should see if we can get better data resolution (sensitivity and accuracy.) Dr. Allen mentioned this before and I'm pretty sure that's why he posted the recent (July 5?) homework questions.
From Dr. Allen:
"I have a little analogy that I'll develop to explain the connection between ppm ("parts per milllion") and pp ("partial pressure").
-- What is your understanding of the difference between those two terms, and as they apply to your CO2 measurements as the ASP-2 heads up and up and down again?
-- Also, would you prefer an analogy in terms of a soccer field, or bumper cars?
(One vote in! Mr. Kibler prefers the bumper car analogy... How about you, Rocketeers?)
First, we need· to get these two (fun!) homework questions answered promptly (since it's 5 PM on Wednesday and they were posted days ago.) I'd like to see the answers on the forum when I Iog on tomorrow. Please get everyone actively involved and then post their collective answers. You decide what to post Andrew, and how to motivate anyone on the team who may need "encouragement". You're the Team Captain.
Why don't you (the Team) ask Dr. Allen how we can get better resolution on the CO2 data? It will involve adding a signal amplifier chip, I believe (he mentioned this before.) At the same time that you (the Team) ask him about getting better resolution, also ask him if the trade-offs are worth it (limited physical space on the BOE, more "off-board" wiring, a new and different program, more time, increased cost, etc.)
Finally Andrew, I would like to see your ASP-2 clone (Phidippides) fully operational and outputting consistent data in a week or so. It will be the back-up ASP in Nevada-- or the circuit board that goes on the second flight-- and so it's important that it runs perfectly. Rocketeers, are you designing and building on the Parallax circuit boards I got you? Are you reading the "What's A Microcontroller Book?" The program is pretty solid at this point Andrew, and you can use it with full confidence. It's the wiring that will take time, and patience. I have the wiring schematics if you need them. They're also posted on the forum.
Be safe, have fun, and enjoy the journey. I'll look for the homework answers and the team's questions on the forum tomorrow.
Aim high,
Mr. Kibler
===============================
Sylvie, is the World Cup over...? I'm waaaaaaaaaaaaaaaay out in the sticks where there is no cell receptions, etc. Who won. Espana?
Mark in NH said...
E-mail sent to the Team on July 7th in reply to Andrew's and Dylan's e-mails:
Andrew and Rocketeers,
Hello from hot and humid Ohio (with emphasis on both hot, and humid .) How are things where you are (Florida, New Hampshire, Brazil...?!) It's hard to believe we're headed into the second week of July already.
I worked on the ASP-2 both nights in the hotel traveling out here and it (the original ASP) is working quite well. I'll post the graphs and raw data once I transfer it from the other computer. I still need to figure out the wiring on my clone because it's not working right. The program is cranking out solid data and the ASP-2 is performming predictably. Now we should see if we can get better data resolution (sensitivity and accuracy.) Dr. Allen mentioned this before and I'm pretty sure that's why he posted the recent (July 5?) homework questions.
From Dr. Allen:
"I have a little analogy that I'll develop to explain the connection between ppm ("parts per milllion") and pp ("partial pressure").
-- What is your understanding of the difference between those two terms, and as they apply to your CO2 measurements as the ASP-2 heads up and up and down again?
-- Also, would you prefer an analogy in terms of a soccer field, or bumper cars?
(One vote in! Mr. Kibler prefers the bumper car analogy... How about you, Rocketeers?)
First, we need to get these two (fun!) homework questions answered promptly (since it's 5 PM on Wednesday and they were posted days ago.) I'd like to see the answers on the forum when I Iog on tomorrow. Please get everyone actively involved and then post their collective answers. You decide what to post Andrew, and how to motivate anyone on the team who may need "encouragement". You're the Team Captain.
Why don't you (the Team) ask Dr. Allen how we can get better resolution on the CO2 data? It will involve adding a signal amplifier chip, I believe (he mentioned this before.) At the same time that you (the Team) ask him about getting better resolution, also ask him if the trade-offs are worth it (limited physical space on the BOE, more "off-board" wiring, a new and different program, more time, increased cost, etc.)
Finally Andrew, I would like to see your ASP-2 clone (Phidippides) fully operational and outputting consistent data in a week or so. It will be the back-up ASP in Nevada-- or the circuit board that goes on the second flight-- and so it's important that it runs perfectly. Rocketeers, are you designing and building on the Parallax circuit boards I got you? Are you reading the "What's A Microcontroller Book?" The program is pretty solid at this point Andrew, and you can use it with full confidence. It's the wiring that will take time, and patience. I have the wiring schematics if you need them. They're also posted on the forum.
Be safe, have fun, and enjoy the journey. I'll look for the homework answers and the team's questions on the forum tomorrow.
Aim high,
Mr. Kibler
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Sylvie, is the World Cup over...? I'm waaaaaaaaaaaaaaaay out in the sticks where there is no cell receptions, etc. Who won. Espana?
Hi Mr. Kibler,
The temperature down here in Florida is just about right, but it is very humid -- Phidippides told me so! I will have much more time this week to get working on integrating the CO2 sensor with Phidippides, so I'll be sure to let you know how that goes. I will be sending out an e-mail to the team shortly reminding them of the homework questions that were posted to the forum, and as well as some possible meeting dates (the 24th or 25th at my house). I'm having a bit of trouble logging into my e-mail account today, so I may be sending it from another address.
Why don't you (the Team) ask Dr. Allen how we can get better resolution on the CO2 data? It will involve adding a signal amplifier chip, I believe (he mentioned this before.) At the same time that you (the Team) ask him about getting better resolution, also ask him if the trade-offs are worth it (limited physical space on the BOE, more "off-board" wiring, a new and different program, more time, increased cost, etc.)
===============================
Sylvie, is the World Cup over...? I'm waaaaaaaaaaaaaaaay out in the sticks where there is no cell receptions, etc. Who won. Espana?
The World Cup final game is on Sunday, but the semifinals were yesterday (Netherlands/Urugay)·and today (Spain/Germany). The finalists: the Netherlands and Espana (yippee!). The Netherlands beat Uruguay, who frankly did not deserve to win, as they won their last match (over Ghana) on a deliberate "hand ball" block of a sure goal.
If you get a chance to see the LDRS show on rocketry that Andrew mentioned, take a look at the "Mega Dark Star" launch by Tim "Wildman" Lehr and "Crazy Jim". Those are the guys I fly with regularly here in Wisconsin. Tim is our motor vendor, and I'm working with Crazy Jim to put together some circuit boards to use with a fancy data logging altimeter that Tim sells.
I also see that in the new issue of Sport Rocketry (the member magazine for the National Association of Rocketry) there's a piece on a guy who is building a computer-controlled rocket that will ideally use GPS and a steerable parachute to fly the rocket back to the rangehead. He has a lot of good stuff working already, but as for steering the rocket under parachute, I'll believe it when I see it. I managed a university team in a contest with eight teams that tried it (the other seven were all groups of engineers), and no-one came even close to getting it to work.
I know you want Spain to win the world cup, but who do you THINK is going to win? I believe that Spain is going to win, but I haven't watched any of the Netherland games to see how good they are.
Did you happen to watch the Spain game yesterday? I watched most of the second half, and I saw Puyol's header. I was happy that Germany lost beacuse they beat Argentina, and they were my second choice. Brazil was my first and that gives me a very good reason to want the Netherlands to lose.
Tracy Allen said...
I have a little analogy that I'll develop to explain the connection between ppm ("parts per milllion") and pp ("partial pressure").
-- What is your understanding of the difference between those two terms, and as they apply to your CO2 measurements as the ASP-2 heads up and up and down again?
-- Also, would you prefer an analogy in terms of a soccer field, or bumper cars?
Dr. Allen,
Here is how we understand the differences and similarities of ppm (parts per million) and pp (partial pressure).
Parts per million is used to measure the relative content of a gas in a large measurement. The phrase means "out of a million" and 1 ppm equals 0.0001%. This is a very standard unit of measurement, and we plan to use this unit to compare and study our data. In the case of the ASP-2, as the content of CO2 rises, the output of mV decreases.
Partial pressure, in our situation, would be the pressure the CO2 would exert, if it were the only gas present in the mixture of gases of the atmosphere. Justin also found out that there is a special acronym relating to our project, called pCO2, which means partial pressure of carbon dioxide. In the case of the ASP-2, when the altitude increases, the atmospheric pressure increases as well -- so theoretically, the pCO2 should decrease. Is this correct?
Also, our team unanimously decided on the bumper car analogy.
Sorry I've been very busy with the 4th of July·and everything,·I've been on vacation with absolutely no way of getting onto a computer, I was at Hampton for a while and then camping, I tried to access the internet at both places, but was unsuccessful.·But I do have my answers to Dr. Allen's 2 questions:
1.) What is your understanding of the difference between those two terms, and as they apply to your CO2 measurements as the ASP-2 heads up and up and down again?
A.)
Parts per million: A standard gas measurement that we will be using to measure/study/compare our data from the ASP-2. It's used to·measure a large amount of gas (such as CO2), 1 ppm= 0.0001%. Content rises, output mV decreases.
Partial Pressure:·Pressure from what the gas (in our case CO2) "exhales" in a way... or·exerts in other words.
2.) Also, would you prefer an analogy in terms of a soccer field, or bumper cars?
A.) As Andrew said, we agreed on the bumper cars.
Soy esperanza de que España ganará todos, ahora que Ghana que se está en una obra barata... Sólo mala suerte supongo … España ¡ buena suerte! (Does that make sense?) I'm not very fluent in any other language, but there's my attempt based off an old English-Spanish Dictionary
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔ "Learn to obey before you command."
I have been teaching physics, engineering and sometimes robotics at a large high school in your area for 9 years. I am also a huge fan of Stamps, Propellers and Parallax in general. I met Dr. Allen at the Propeller EXPO in Rocklin a few weeks ago and he encouraged me to contact you. I am very interested in your project and would love to learn more about ARLISS and what you do. I have been interested in starting a similar club at our school, possibly TARC (Team America Rocketry Challenge) or something similar.
Would it be OK if I came for a visit? Please reply with a private message so I can give you more information and we can discuss details.
That sounds to me like it would be great! But I'm not the team leader, you're probably going to have to wait for Mr. Kibler and Andrew to get an answer for sure. It might take a day or two because they are on vacation I believe. Where do you teach?
-Mike
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔ "Learn to obey before you command."
That sounds to me like it would be great! But I'm not the team leader, you're probably going to have to wait for Mr. Kibler and Andrew to get an answer for sure. It might take a day or two because they are on vacation I believe. Where do you teach?
-Mike
Mike,
Indeed, it sounds like a great opportunity! I have already sent a PM to you, Lev, with Mr. Kibler's e-mail address if you would like to get in touch with him, along with some general information about the ARLISS program.
I have been teaching physics, engineering and sometimes robotics at a large high school in your area for 9 years. I am also a huge fan of Stamps, Propellers and Parallax in general. I met Dr. Allen at the Propeller EXPO in Rocklin a few weeks ago and he encouraged me to contact you. I am very interested in your project and would love to learn more about ARLISS and what you do. I have been interested in starting a similar club at our school, possibly TARC (Team America Rocketry Challenge) or something similar.
Would it be OK if I came for a visit? Please reply with a private message so I can give you more information and we can discuss details.
Sincerely,
Lev
Hi Lev,
· This Mark Kibler and I'm one of the educational mentors for the ARLISS/Parallax project. Thanks for joining·the forum.·As you can see we have other excellent mentors guiding us along in the project. They include Tracy Allen and Paul Smith (Sylvie.) Paul and I both have experience with the Team American Rocketry Challenge (TARC). I mentored teams for five years and we qualified for the TARC national finals all five years. One year we placed high enough at the TARC nationals to qualify for the NASA Student Launch Initiative (SLI). Our current project has its roots in the NASA/SLI project (which we actually did for two consecutive years.) That opened another door of opportunity, the ARLISS project (www.arliss.org). ARLISS is a collaboration between Stanford University and Aerospace Research of the Pacific (Aeropac). The TARC team Paul co-mentored, Madison West high school in Wisconsin ("Mad West"), actually won the TARC nationals two years ago. Yea, Paul! Go, Mad-West!
So where and what·do you teach? How can we help you with TARC?·Are you interested in doing some sort of·a colloborative project? Thanks again for joining "our" forum. We look for your reply.
Regards,
Mark and the Rocketeers (Tracy, Paul, et al*. *There is no one named 'Al'.)
Tracy Allen said...
I have a little analogy that I'll develop to explain the connection between ppm ("parts per milllion") and pp ("partial pressure").
-- What is your understanding of the difference between those two terms, and as they apply to your CO2 measurements as the ASP-2 heads up and up and down again?
-- Also, would you prefer an analogy in terms of a soccer field, or bumper cars?
"... there is a special acronym relating to our project, called pCO2, which means partial pressure of carbon dioxide. In the case of the ASP-2, when the altitude increases, the atmospheric pressure increases as well -- so theoretically, the pCO2 should decrease. Is this correct?
Also, our team unanimously decided on the bumper car analogy.
Thank you,
Andrew
Andrew and Mike,
·· Good research on coming up with "pCO2, which means partial pressure of carbon dioxide." But are you sure that pCO2·(CO2 pressure) increases as altitude increases...? Does that makes sense? What does Boyle's Law have to say on the matter? Please·locate Boyle's Law, study it,·then post it here on the forum with·the formula and your explanation. As I said (all too many times) in science class,·your "definitions should be brief, concise, written in your own words, and easy for anyone to understand." I'm also eager to hear what Dr. Allen and Sylvie (and Lev?) have to say on the matter.
I'm just as eager to·find out·who will win the World Cup...! I will cheer for Espa~na! Go... um... uh... (what's their team name?)... Go Matadors!·Hit a home run for the team! (*Please don't tell me·the World Cup is·already over... I know Sylvie said the game is on Sunday. It wasn't LAST Sunday was it?!) *Apply logic and look at the dates of the posts to the forum. Logic says·the finals are·this coming Sunday.)
Comments
I thought they where neither? ...that they, "were" mV but they got multiplied by the ADC. By my understanding they are an undefined unit of measurement (Not as much a ft and what not).
Dylan,
As I understand it the ADC (Analog-to-Digital Converter) does just that: it changes the analog signal from the CO2 sensor in digital numbers (0's and 1's) then ultimately into ppm numbers when the correct algorithm (an equation, or a multiplied value) is added into the program.
Andrew, Sylvie , or Dr. Allen, can you explain analog-to-digitala conversion simply? I don't want to misinform the Rocketeers...
There is an inconsistency there. If CNTL is connected to p4, then HIGH 4 should be on, not HIGH 3. If CNTL is in fact connected to p4 and p4 is floating (not commanded to be either HIGH or LOW), then you could expect dicey results. But the fact that the heater is on suggests that the CO2 sensor is in fact active.
The MCP3202 ADC uses a technique called successive approximation. It takes 12 steps and makes 12 comparisons. It goes like this.
1) Is the signal greater than than 1/2 the power supply voltage? Yes=1 No=0. That is the most significant bit.
2) If the result in step 1 was Yes=1, then, is the signal greater than 3/4 the power supply? Yes=1, No=0
If the result in step 1 was No=0, then, is the signal greater than 1/4 the power supply? Yes=1, No=0
That is the second most significant bit.
3..) The same process continues for 10 more steps, each time choosing to branch up or down depending on the previous result.
It branches up for a 1 and down for a zero, and at each branch it narrows down the window around the signal...
The final result is a pattern of zeros and ones that are the pattern of branching comparisons that zoom in on the signal
Internally it is adding up the weights of each bit, as follows
2048..1024..512..256..128..64..32..16..8..4..2..1
It adds the weight if the bit is 1, and adds zero if the bit is zero.
For example, CO2pp=101010101010 means up,down,up,down
2048 + 512 + 128 + 32 + 8. + 2 =
Homework: add up the numbers
Homework: What is the sum for this binary number? 110011101111
Internally the process is a lot simpler than it sounds. It is a very clever but dumb decision making circuit inside that little chip.
The final number that comes out of the ADC is a proportion of the power supply voltage as the reference. So if the power supply is 5000 mV, the program has to multiply by 5000/4096 = 1.2207 in order to convert the ADC result to mV. The conversion to ppm will be another step.
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Tracy Allen
www.emesystems.com
Baseball is going great. I play 2nd base, I can catch, and sometimes on the town team (WAC) I play first. We are 4-4. Today is my first playoff game for WAC, and if we win this game we goto the championship game on saturday. For the highschool summer league team, we are 4-2 and I play either 2nd base or right field.
Dr.Allen,
The MCP3202 ADC's "successive approximation", this is something that is built into the chip, right?
Thank you all for your time and help,
Sean
Yes, the successive approximation is built into the chip.
I'm glad to know you are doing baseball. I enjoy baseball myself too, at least watching it. Here in the SF bay area we have the A's and the Giants. I follow them both. I'll be in Chicago for the 4th, home of the Cubs and the White Sox, another cross town rivalry. After the 4th my wife and I will head up to my sister's house on Lake Michigan for a couple of days. They live right on the lake.
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Tracy Allen
www.emesystems.com
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Tracy Allen
www.emesystems.com
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I went to a minor league game in Beloit last night, the Twins' Midwest League Class A affiliate. The big surprise was that the Beloit Snappers' starting shortstop and leadoff hitter was none other than JJ Hardy, longtime Brewer and current Twins major-leaguer, who was in a Beloit on a three-day rehab assignment. It was good to see him, though he took the collar in 3 ABs.
The fun "minor league atmosphere" part of the game came right after the final out in the Snappers' loss: some elderly guy down the first base line shouted "Dagnabbit!".
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ARLISS content:·· (* You probably do not need any of this for your project - it's just thought exercises *)
Notice that the Alarm function has only two possible values: on and off. You could use a Byte-sized variable to represent whether or not the alarm was on, but you'd only be using one bit of that entire 8-bit variable. The possible values of the variable would be
Off -00000000
On·-00000001
Suppose you had another sensor that also had an alarm function. You could have a Byte-sized variable for that alarm as well, or you could code the two alarms into one variable:
Sensor 1·· 2
········ Off· Off· 00000000
········ On··Off·· 00000001
········ Off· On·· 00000010
········ On··On···00000011
You can see that you could have up to eight "on - off" variables held in that one byte, which would save you up to seven bytes' worth of variable space compared with a program that used one Byte-sized variable for each of the 8 alarms.
If you had two sensors each of which had 16 possible values, you could still code both in one Byte-sized variable:
Sensor
1···· ··· 2
0000··· 0000· (both S1 and S2 = 0)
0001··· 0000 (S1 = 1, S2 = 0)
0100··· 1000 (S1 = 4, S2 = 8)
1011··· 1001 (S1 = 11, S2 = 9)
and so on. This is where it's sometimes nice to use hexadecimal (base 16), because then you get a two-digit number where each digit tells you the value of one of the two variables held in that one byte:
Hex:
00· (both S1 and S2 = 0)
10· (S1 = 1, S2 = 0)
48 (S1 = 4, S2 = 8)
B9 (S1 = 11, S2 = 9: 11 is "B" in hex)
Those same values written in decimal wouldn't tell you much:
0
16
72
185
Post Edited (sylvie369) : 7/1/2010 7:26:45 PM GMT
2) HIGH 3 was on
3) TP1 to CH0, to 3 to CH1
4) ALM to p3 and CNTL (HSW) to p4
My mistake. It was a simple typo, that's all. I meant HIGH 4, not HIGH 3.
We've had the ASP-BOE running for nearly three hours WITH HIGH 4 'OFF' (commented out) and we a couple of observations:
1) Yes, it does take the CO2 sensor (is heater active?) quite a while to warm up and then stabilzie to amibient conditions (45 minutes or so.)
2) The metal CO2 sensor is NOT HOT after 2 hours. Conclusion: the heater is, in fact, "OFF"
3) Once it's 'warmed up' (with HIGH 4 off??) and stable, the data fluctuations stabilized are less. Put another way, there's a narrower range between the highest and lowest readings during that particular 4-5 minute phase/point in time.
4) When we graphed the data earlier (for a shorter 1-1/2 hour 'trial') the graph looked a lot like the one you posted... hmmm. Curious.
I (and we, the Rocketeers!) enjoyed the expalanation of "successive approximation." It was sure interesting and it generated a lot of 'back channel chatter" by e-mail. They're working on the answers to the questions you posted as we "speak'.
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I have to run Christopher to work and I'll post the lastest graph when I return. He's a "Flood Plain Ranger" at the Society for the Protection of New Hamsphire Fores and he patrols the trails and does trail work. Good summer job for a good kid.
Mark
The attached two graphs have self-explanatory text beneath. We're still trying to figure this glitch out. We must have it wired wrong somewhere... We've looked under the hood and in the trunk but we'll stick with it and report back. This HIGH 4 thing is an interesting mystery, better than any cryptoquote puzzle. When we solve HIGH 4 we'll hope for a "high 5!"
Stay tuned for details,
Mark and Chris
"I'm attaching a variation on the 27929 CO2 sensor DEMO program, the one I've been using to test the CO2 sensor using the same pins as I think are used in the ASP-2 program."
Thanks Tracy. I'm running the modified demo program right now. Mostly 0's in the ADC0 column but it's only been running for 5 minutes. The heater may need to heat up so I'll wait a while and see what happens. I have a hunch that it's something in the wiring at this end. But nothing looks awry. Eventually it will prove to be something simple (and probably silly.) But silly is good.
=====================================
Will you get to see a Cubs or White Sox game while you're in Chicago? Or will you track down another Turing machine and the wooden nickle maker? Come to think of it, the Fermi Lab and the Field Museum are also there.... lots of possibilities!
You said, " I have no doubt someone has those skills (devising another Turing machine v.2) - probably someone right here on the Parallax forums." I like to believe that you, Sylvie and I are giving that spark of interest and curiosity to some bright young mind, our Rocketeers. You can never really quantify what a kid learns (I'd like to do away with that artifice called 'grades' altogether) and you never know where knowledge and imagination will lead someone. That's the beauty, isn't it? One of these tykes might invent something that we could never conceive nor imagine.
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15 minutes into the demo program and still getting mostly 0's.
Dr. Allen,
Here are the answers to your recent homework questions. Our team discussed them thoroughly via e-mail earlier today, and I believe they are correct.
Homework question 1: 2048 + 512 + 128 + 32 + 8 + 2 = 2730
Homework question 2: We might not be interpreting the term "sum" correctly in this case, but we believe you are asking what the binary value equals. In this case, 110011101111 has a decimal value of 3311. I used a special calculator to get this value, and Dylan received the same number using his own method. Is this correct?
Thank you,
Andrew
Post Edited (Andrew (ARLISS)) : 7/2/2010 1:53:17 AM GMT
2048+1024+128+64+32+8+4+2+1=3311 Yes!
You are right about the this being the same as what the binary value equals.
Here is the last one with all the zeros and ones written out:
2048*1 + 1024*1 + 512*0 + 256*0 + 128*1 + 64*1 + 32*1 + 8*1 + 4*1 + 2*1 + 1*1 = 3311
See the powers of two, and the binary 110011101111?
Here is another way to write it with powers of 2:
211*1 + 210*1 + 29*0 + 28*0 + 27*1 + 26*1 + 25*1 + 24*0 + 23*1 + 22*1 + 21*1 + 20*1 = 3311
That last form is called a polynomial. Have you heard that term? That is how mathematicians think of positional numbers, like binary (base 2) 101010101010 or decimal (base 10) 1234567 or hex (base 16) $F17A. Positional number systems are shorthand for polynomials.
I'm also looking at the graphs from the 4.5 hour test, you posted at 1:55pm. There does seem to be some glitch in the workings and you will probably say, "aha!" or "huh?!" or "duh!" when you find it. You're looking for something like a Ground wire that isn't quite connected. Wires can be off by one connection point, or a wire is broken or doesn't make good contact. The CO2 reading should not be zero, even near the beginning of a run.
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Tracy Allen
www.emesystems.com
Post Edited (Tracy Allen) : 7/2/2010 6:40:41 AM GMT
Excellent work on getting your homework done and collaborating with Andrew by e-mail to cross-check your answers. You really are coming together nicely as a team. Speaking of which, it looks like Mike will be·making the trip to Nevada with us! All five of you together to stretch our budget but Mike will be joining us. I'll ask for a really BIG room...!
Tracy, Sylvie, and Rocketeers--
·· I think I may have fried the BOE, stamp, ADC, or (likely?) the CO2 module <
it was really (REALLY) hot at one point. I'm not sure·exactly what happened·and I'm backtracking·and troubleshooting from square one. I agree that it will probably·prove to be·something simple and silly.
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After running the ASP-BOE clone successfully for hours, just when it looked like we were "so close" with the program.... things stopped working!!· ·
The bottom line is, I got repeated "No Stamp recognized" error messages. The program would try to initialize and then a "No Stamp recognized" error message appeared, repeatedly. Sometimes it wouldn't even try to initialize and I would get the error message instantly. Was the circuitry overheating after running for·hours (and off and on for days?)
==============================
Christopher and I rebuilt/ rewired a third ASP-BOE clone (with·components from our spare parts box, not from the "fried" ASP-BOE), etc., etc. and the same thing happened.·We tried all the logical fixes-- switched the serial input cable, ran a different program, switched out the BASIC stamps, CO2 sensor module, ADC chip, resistors, etc., with similar results. This happened late in the evening and·we had·been working·on it off and on all·day.·Chris went to work at 4 and I puttered with it until he got home at 9, then until midnight after he went to bed. So maybe I was just tired.
I'm sure Tracy, that it'll prove to be something simple like you said. In the mean time I'll build two·more ASP-BOE clones and order·all the requisite extra parts from Parallax "just in case" I toasted some circuitry.
I'm in Maine now, then back to New Hampshire, then out if state for a few weeks. I have my ASP-BOE travel kit already packed. I really enjoy figuring things like this out... better than any good mystery novel!
From Maine,
Mark
I have a little analogy that I'll develop to explain the connection between ppm ("parts per milllion") and pp ("partial pressure").
-- What is your understanding of the difference between those two terms, and as they apply to your CO2 measurements as the ASP-2 heads up and up and down again?
-- Also, would you prefer an analogy in terms of a soccer field, or bumper cars?
The world cup Germany-Argentina game was really something. Talk about teamwork and precision footwork on the part of the Germans. Alemania, as we were watching on Spanish language TV.
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Tracy Allen
www.emesystems.com
·· Consider Murphy (and his law) banished (or rather, exorcised.)·The ASP-BOE is purring away, cranking out near-perfect millivoltage and CO2 "data," After·troubleshooting for a little while, Christopher, Bandit the Rocket Dog, and I have concluded·that it was simply loose wires. Nothing more!··
···································································· ·
Now I understand why you suggested that we to solder the wires to perfboard... advice that is now·well underdstood and well taken, and another excellent·lesson learned (in retrospect we were lucky that last year's ASP-BOE didn't fall victim to·loose wire during one of its two high-G, high-altitude flights. Now that the problem is solved we'll retire the ASP-BOE for the rest of the long holiday weekend.
++++++++++++++++++++++++++++++++++++++++
So you're off on your adventure to the Windy City, yes? I hope you have a fun and relaxing time with your family and friends. Be safe, too. I'm eager to hear all about the things you'll see and do in Chicago. I hope no particles come flying off of the Fermi Lab Particle Accelerator while you're there (the folks ast the rental car company don't appreciate holes in the side of their new cars.
++++++++++++++++++++++++++++++++++++++++
Time to put charcoal on the grill· and take the sea kayaks out (and put the gadgetry away.) Our summer cottage is the red and green Victorian on the right in the attached picture and there's plenty of daylight left. You and Sylvie are welcome to come any time... for a day, a week, or a summer. It's in Orr's Island, Maine, about 12 miles from Bowdoin College. Take care, have fun, and
Best regards from Maine,
Mark
Great biking around here the last few days, and while I didn't watch Germany play, I did see the Spain-Paraguay match.
I don't think you can expect a reliable device in a rocket with connections that aren't soldered. You're pulling double-digit G forces under power, and probably even higher forces when the ejection charges go off. Things have to be mounted very solidly. I flew an SD card datalogger a few times, but eventually gave up because the SD card kept popping out of the socket when the ejection charge went off.
Happy 4th of July (almost.) So when do you want to come to Maine? We'll go sea kayaing, sailboating, or fishing for mackerel (Holy Mackerel!) The when we get back we'll all have lobster, fresh from the lobster pound* across the bridge (*it's like a dog pound, but for lobsters I guess.)
So where did you go biking? Do you mountain bike or·ride the roads? Be careful wherever you ride and be sure to wear your helmet. Remember Susanne's horrific bicycling accident last October? Her helmet literally saved her life. When the car hit her from behind she was catapulted head first into a tree. It was a terrible accident but·I think it would have been much worse if she hadn't been wearing her helmet.
What are you plans for the 4th? A baseball game? Pyrotechnics? Watching World Cup Soccer? I've lost track of who's·still in it...! I take it Germany, Spain, and Paraguay are still in? It most be getting close to the·Final Four (do they call it that?)· A friend of ours and her daughter are both soccer officials and they've been glued to the TV watching the World Cup (not literally of course. That would be messy and make it hard to see the game.) They're from New Zealand and they're rabid about 'football'. I get corrected every time I call it 'soccer'. "Sacrilege!", Chantal says. I should look up the meaning of 'sacrilege.' It must mean "You rock!" or soemthing like that because she says it with such emphasis.
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The *original* ASP-BOE-MAWD works perfectly now and it cranks out mV and CO2 data almost flawless (temperature, humidity, too...!) Thank you Tracy and Paul!·I admire and envy your knowledge and skills, and I also learning lots this·year, probably more than ever.·But we can't seem to get the two clones to work nearly as well as ASP-1. Maybe it's the wiring or maybe it's because we don't have a MAWD wired to the clones, or both.Would the MAWD not·being·wired to the BOE affect the clones so much (erratic data, wide data range, corrupt data on the flash drive)?·In any event the original ASP-BOE is working really, really·well right now. But we ought to have a back-up·"just in case", and·more importantly we ought to be able to answer the question·"Why?" As you know, rocketry and computer programming are very existential (but I don't know "why"...)
Happy 4th from Maine,
Mark
I ride my bike on bike trails, mostly rails-to-trails. I have to admit that I do not wear a helmet. Yes, I know. Really, yes, I know.
I don't really plan much for tomorrow. Today after the Spain-Paraguay match, I attended my first Tour de Fat (Google it!). It was like the Field of Dreams, a Grateful Dead concert, and the 4th of July all wrapped up into one event.
The remaining World Cup teams are Germany, Spain, the Netherlands, and Uruguay. I've never been to Uruguay, so I guess I'll be terribly disappointed if they win it: Spain is my first choice, of course. Wow, the play in that game today was SO much better than in either of the France matches I watched. The goaltenders were unbelievable.
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So are you saying that the ASP-BOE-MAWD is giving you mV data from the CO2 sensor that match the voltage on TP1? (when you measure it with the voltmeter?) That's the real test, I think, of the CO2 sensor hookup. I believe you still need to work out how you're going to convert the voltage reading to CO2 content, and that Tracy has some plans for getting you through that.
I can't see any reason why not having a MAWD hooked up should affect the rest of the system - except that if the program is looking for altitude data and not getting them, it may be trying to put random junk on the screen and into the output to the USB drive. That's a programming issue, and therefore one you should take up with Tracy: the question is "what happens when the program runs on a BoE that doesn't receive any altitude data?". It'll be important to consider that because as you'll remember, before takeoff and during the first 160 feet of flight, you won't get any altitude data, and you need to have a program that can handle that fact.
I just got in from snorkeling with Susanne, Christopher, Bandit the Rocket Dog (sans snorkel), Lenora, and Tim. We saw a gigantic horseshoe crab, bigger than a bushel basket. The folks at the cottage next door are having their annual "spud gun" event. One guy even has a Gattling spud gun! They tether helium balloons in the water and then shoot potatoes at them... lots of well-fed crabs and lobsters today! They (the neighbors, not the lobsters) even have spud gun trophies made up for the event. Then they have a barbecue, beans, and lobster. The folks at the other cottage are having a down-home Maine clam bake right on the beach. Fun on the shores of Maine today. You outta come visit (caveat: not everyone is a techhie or as silly as the·neighbors and I. Lots of stoic Mainers around, too. Hurrah for stoicism!)
Mark
For those of you still awake, you should consider tuning to the Science channel where this year's Large Dangerous Rocket Ships (LDRS 29) coverage is being aired. There are some really big and fast rockets, that make even our ARLISS rocket seem small.
http://science.discovery.com/tv/ldrs/
Good morning?
Andrew
Andrew and Rocketeers,
·· Hello from hot and humid Ohio (with emphasis on both hot, and humid···
I worked on the ASP-2 both nights in the hotel traveling out here and it (the original ASP) is working quite well. I'll post·the·graphs and raw data·once I transfer it from the other computer.·I still need to figure out the wiring on my clone because it's not working right. The program is cranking out solid data and the ASP-2 is performming predictably. Now we should see if we can get better data resolution (sensitivity and accuracy.) Dr. Allen mentioned this before and I'm pretty sure that's why he posted the recent (July 5?) homework questions.
From Dr. Allen:
"I have a little analogy that I'll develop to explain the connection between ppm ("parts per milllion") and pp ("partial pressure").
-- What is your understanding of the difference between those two terms, and as they apply to your CO2 measurements as the ASP-2 heads up and up and down again?
-- Also, would you prefer an analogy in terms of a soccer field, or bumper cars?
(One vote in! Mr. Kibler prefers the bumper car analogy... How about you, Rocketeers?)
First, we need· to get these two (fun!) homework questions answered promptly (since it's 5 PM on Wednesday and they were posted days ago.) I'd like to see the answers on the forum when I Iog on tomorrow. Please get everyone actively involved and then post their collective answers. You decide what to post Andrew, and how to motivate anyone on the team who may need "encouragement". You're the Team Captain.
Why don't you (the Team) ask Dr. Allen how we can get better resolution on the CO2 data? It will involve adding a signal amplifier chip, I believe (he mentioned this before.) At the same time that you (the Team) ask him about getting better resolution, also ask him if the trade-offs are worth it (limited physical space on the BOE, more "off-board" wiring, a new and different program, more time, increased cost, etc.)
Finally Andrew, I would like to see your ASP-2 clone (Phidippides) fully operational and outputting consistent data in a week or so. It will be the back-up ASP in Nevada-- or the circuit board that goes on the second flight-- and so it's important that it runs perfectly. Rocketeers, are you designing and building on the Parallax circuit boards I got you? Are you reading the "What's A Microcontroller Book?" The program is pretty solid at this point Andrew, and you can use it with full confidence. It's the wiring that will take time, and patience. I have the wiring schematics if you need them. They're also posted on the forum.
Be safe, have fun, and enjoy the journey. I'll look for the homework answers and the team's questions on the forum tomorrow.
Aim high,
Mr. Kibler
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Sylvie, is the World Cup over...? I'm waaaaaaaaaaaaaaaay out in the sticks where there is no cell receptions, etc. Who won. Espana?
Hi Mr. Kibler,
The temperature down here in Florida is just about right, but it is very humid -- Phidippides told me so! I will have much more time this week to get working on integrating the CO2 sensor with Phidippides, so I'll be sure to let you know how that goes. I will be sending out an e-mail to the team shortly reminding them of the homework questions that were posted to the forum, and as well as some possible meeting dates (the 24th or 25th at my house). I'm having a bit of trouble logging into my e-mail account today, so I may be sending it from another address.
Andrew
If you get a chance to see the LDRS show on rocketry that Andrew mentioned, take a look at the "Mega Dark Star" launch by Tim "Wildman" Lehr and "Crazy Jim". Those are the guys I fly with regularly here in Wisconsin. Tim is our motor vendor, and I'm working with Crazy Jim to put together some circuit boards to use with a fancy data logging altimeter that Tim sells.
I also see that in the new issue of Sport Rocketry (the member magazine for the National Association of Rocketry) there's a piece on a guy who is building a computer-controlled rocket that will ideally use GPS and a steerable parachute to fly the rocket back to the rangehead. He has a lot of good stuff working already, but as for steering the rocket under parachute, I'll believe it when I see it. I managed a university team in a contest with eight teams that tried it (the other seven were all groups of engineers), and no-one came even close to getting it to work.
I know you want Spain to win the world cup, but who do you THINK is going to win? I believe that Spain is going to win, but I haven't watched any of the Netherland games to see how good they are.
Did you happen to watch the Spain game yesterday? I watched most of the second half, and I saw Puyol's header. I was happy that Germany lost beacuse they beat Argentina, and they were my second choice. Brazil was my first and that gives me a very good reason to want the Netherlands to lose.
Sean
Dr. Allen,
Here is how we understand the differences and similarities of ppm (parts per million) and pp (partial pressure).
Parts per million is used to measure the relative content of a gas in a large measurement. The phrase means "out of a million" and 1 ppm equals 0.0001%. This is a very standard unit of measurement, and we plan to use this unit to compare and study our data. In the case of the ASP-2, as the content of CO2 rises, the output of mV decreases.
Partial pressure, in our situation, would be the pressure the CO2 would exert, if it were the only gas present in the mixture of gases of the atmosphere. Justin also found out that there is a special acronym relating to our project, called pCO2, which means partial pressure of carbon dioxide. In the case of the ASP-2, when the altitude increases, the atmospheric pressure increases as well -- so theoretically, the pCO2 should decrease. Is this correct?
Also, our team unanimously decided on the bumper car analogy.
Thank you,
Andrew
Sorry I've been very busy with the 4th of July·and everything,·I've been on vacation with absolutely no way of getting onto a computer, I was at Hampton for a while and then camping, I tried to access the internet at both places, but was unsuccessful.·But I do have my answers to Dr. Allen's 2 questions:
1.) What is your understanding of the difference between those two terms, and as they apply to your CO2 measurements as the ASP-2 heads up and up and down again?
A.)
Parts per million: A standard gas measurement that we will be using to measure/study/compare our data from the ASP-2. It's used to·measure a large amount of gas (such as CO2), 1 ppm= 0.0001%. Content rises, output mV decreases.
Partial Pressure:·Pressure from what the gas (in our case CO2) "exhales" in a way... or·exerts in other words.
2.) Also, would you prefer an analogy in terms of a soccer field, or bumper cars?
A.) As Andrew said, we agreed on the bumper cars.
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Soy esperanza de que España ganará todos, ahora que Ghana que se está en una obra barata... Sólo mala suerte supongo … España ¡ buena suerte! (Does that make sense?) I'm not very fluent in any other language, but there's my attempt based off an old English-Spanish Dictionary
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"Learn to obey before you command."
-Solon
I have been teaching physics, engineering and sometimes robotics at a large high school in your area for 9 years. I am also a huge fan of Stamps, Propellers and Parallax in general. I met Dr. Allen at the Propeller EXPO in Rocklin a few weeks ago and he encouraged me to contact you. I am very interested in your project and would love to learn more about ARLISS and what you do. I have been interested in starting a similar club at our school, possibly TARC (Team America Rocketry Challenge) or something similar.
Would it be OK if I came for a visit? Please reply with a private message so I can give you more information and we can discuss details.
Sincerely,
Lev
That sounds to me like it would be great! But I'm not the team leader, you're probably going to have to wait for Mr. Kibler and Andrew to get an answer for sure. It might take a day or two because they are on vacation I believe. Where do you teach?
-Mike
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"Learn to obey before you command."
-Solon
Mike,
Indeed, it sounds like a great opportunity! I have already sent a PM to you, Lev, with Mr. Kibler's e-mail address if you would like to get in touch with him, along with some general information about the ARLISS program.
Thank you,
Andrew
· This Mark Kibler and I'm one of the educational mentors for the ARLISS/Parallax project. Thanks for joining·the forum.·As you can see we have other excellent mentors guiding us along in the project. They include Tracy Allen and Paul Smith (Sylvie.) Paul and I both have experience with the Team American Rocketry Challenge (TARC). I mentored teams for five years and we qualified for the TARC national finals all five years. One year we placed high enough at the TARC nationals to qualify for the NASA Student Launch Initiative (SLI). Our current project has its roots in the NASA/SLI project (which we actually did for two consecutive years.) That opened another door of opportunity, the ARLISS project (www.arliss.org). ARLISS is a collaboration between Stanford University and Aerospace Research of the Pacific (Aeropac). The TARC team Paul co-mentored, Madison West high school in Wisconsin ("Mad West"), actually won the TARC nationals two years ago. Yea, Paul! Go, Mad-West!
So where and what·do you teach? How can we help you with TARC?·Are you interested in doing some sort of·a colloborative project? Thanks again for joining "our" forum. We look for your reply.
Regards,
Mark and the Rocketeers (Tracy, Paul, et al*. *There is no one named 'Al'.)
·· Good research on coming up with "pCO2, which means partial pressure of carbon dioxide." But are you sure that pCO2·(CO2 pressure) increases as altitude increases...? Does that makes sense? What does Boyle's Law have to say on the matter? Please·locate Boyle's Law, study it,·then post it here on the forum with·the formula and your explanation. As I said (all too many times) in science class,·your "definitions should be brief, concise, written in your own words, and easy for anyone to understand." I'm also eager to hear what Dr. Allen and Sylvie (and Lev?) have to say on the matter.
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I'm just as eager to·find out·who will win the World Cup...! I will cheer for Espa~na! Go... um... uh... (what's their team name?)... Go Matadors!·Hit a home run for the team! (*Please don't tell me·the World Cup is·already over... I know Sylvie said the game is on Sunday. It wasn't LAST Sunday was it?!) *Apply logic and look at the dates of the posts to the forum. Logic says·the finals are·this coming Sunday.)