Dylan, Mike, and Mr. Kibler,
On the data for the CO2 concentrations at different altitudes, why do some intervals of kilometers not have a corresponding CO2 level? Also, how did you find the CO2 concentraions at each level, since the graphs measured the CO2 levels by month?
sylvie369 said...
I'd say carefully read the documentation for the CO2 Gas Sensor Module, and come back to the forum with whatever questions that raises.
When that module arrives, you'll need to figure out how to get the BS2 to read the CO2 levels from it, and you'll have to do some testing and probably calibration. Do you have more than one BS2? It might be easier to figure out the module while it's set up alone on a second module, rather than while it's connected to all of the other stuff you have on the first module.
Thanks for the suggestion of tinkering around with the CO2 sensor on a separate board. This is probably a good idea so we don't ruin what we already have working. I'll check again later, but I don't see any sample code for the CO2 sensor on it's information page as we have seen in the past with other sensors. How would you suggest going about testing the CO2 sensor once we have it?
How is everyone with understanding the rocket, payload bay, and recovery system? How about with understanding last year's device? Are the new people on the team up to speed on all of that?
I believe everyone, including new team members have at least a basic understanding of the ARLISS rocket, payload bay, and recovery. If any team member still has questions about this year's project or last year's, speak up and feel free to e-mail me.
Justin said...
ylan, Mike, and Mr. Kibler,
On the data for the CO2 concentrations at different altitudes, why do some intervals of kilometers not have a corresponding CO2 level? Also, how did you find the CO2 concentraions at each level, since the graphs measured the CO2 levels by month?
We took the most current data we could find which was the July data. The reason why some do not have readings, I am not sure. After a long, long search this was the only relevant data we could find.
Dylan,
On the graph wouldnt the most currrent data come from December and not July since July is in the middle of the year and December is at the end of the year?
Rocketeers, ··· I agree with Sylvie. One of your next steps is to read the documentation for the CO2 sensor. Andrew and·Dylan have already downloaded it from the Parallax website, printed it out, and put it in their team binder. While we're waiting for the sensor to arrive you should also find some preliminary program code for the CO2 sensor (search the forums) so·you can, as Sylvie suggests, "do some testing."
Sylvie, ··· We do have more than one BOE/ BS2. We can put the new·CO2 sensor on it as a "stand-alone" prototype unit. Once the Rocketeers have it up and running·with a simple program we can·move it over to·last year's·MAWD-BOE and (re)program the·MAwhole thing. Does that seem like a logical progression?
Last year's team members are explaining how the rocket, payload bay, and payload (the ASP/ MAWD-BOE) are integrated to new team members. If time allows I'd like to take the team to a local club launch and launch·my·6" diameter L-2 rocket (without the ASP payload) on a K-350. Then they'll see how the subsystems are integrated.
I say, "If time allows" because my wife was hit from behind by a car while she was·bicycling to work in October,·just after the ARLISS launch. She was in critical care at Dartmouth Medical Center for weeks and in the hospital for months. Her leg bones were shattered (she has titanium rods in them now); her pelvis was broken in three places (she has metal plates); she was catapulated head-first into a tree and her vertebrae "exploded" (burst fractured); she had blood clots in her lungs; and she was unconscious,among other things. Tending to her and her health were, and continue to be, a priority, and "free" time has·come at a premium. She's lucky to be alive and not vegetative.
Just so you and Tracy know, my program skills are not that strong and the schematics confuse me.·That's why I appreciate your help. We can get·the CO2 sensor·up and going if you guys can help with the higher-order programming.
You should really come out to Black Rock and launch with us in September! (September 14-18.)
Best regards,
Mark
sylvie369 said...
I'd say carefully read the documentation for the CO2 Gas Sensor Module, and come back to the forum with whatever questions that raises.
When that module arrives, you'll need to figure out how to get the BS2 to read the CO2 levels from it, and you'll have to do some testing and probably calibration. Do you have more than one BS2? It might be easier to figure out the module while it's set up alone on a second module, rather than while it's connected to all of the other stuff you have on the first module.
How is everyone with understanding the rocket, payload bay, and recovery system? How about with understanding last year's device? Are the new people on the team up to speed on all of that?
Justin Abbott said...
sylvie369,
I remember a very quick and brief explanation of the rocket, payload bay, and recovery system from last year's device. Would you be able to explain it to me more in depth?
Justin
I can answer questions about rockets in general, but I don't know yours as well as your teammates do. It sounds like Andrew would be the best person to answer any questions you have. It'll be good for him to have to explain it, as well. That's a great way to learn things - explaining them to others.
Mark in NH said...··· We do have more than one BOE/ BS2. We can put the new·CO2 sensor on it as a "stand-alone" prototype unit. Once the Rocketeers have it up and running·with a simple program we can·move it over to·last year's·MAWD-BOE and (re)program the·MAwhole thing. Does that seem like a logical progression?
Last year's team members are explaining how the rocket, payload bay, and payload (the ASP/ MAWD-BOE) are integrated to new team members. If time allows I'd like to take the team to a local club launch and launch·my·6" diameter L-2 rocket (without the ASP payload) on a K-350. Then they'll see how the subsystems are integrated.
I say, "If time allows" because my wife was hit from behind by a car while she was·bicycling to work in October,·just after the ARLISS launch. She was in critical care at Dartmouth Medical Center for weeks and in the hospital for months. Her leg bones were shattered (she has titanium rods in them now); her pelvis was broken in three places (she has metal plates); she was catapulated head-first into a tree and her vertebrae "exploded" (burst fractured); she had blood clots in her lungs; and she was unconscious,among other things. Tending to her and her health were, and continue to be, a priority, and "free" time has·come at a premium. She's lucky to be alive and not vegetative.
Just so you and Tracy know, my program skills are not that strong and the schematics confuse me.·That's why I appreciate your help. We can get·the CO2 sensor·up and going if you guys can help with the higher-order programming.
You should really come out to Black Rock and launch with us in September! (September 14-18.)
Oh, I'm really sorry to hear about your wife. I'm an avid biker, out on a trail somewhere most summer days, and this kind of story terrifies me. My mom was hit while biking about 12 years ago - not nearly that bad, but her helmet was crushed, which is pretty scary.
I'd love to comeout to Black Rock, and I'll try, but that is the second week of the school year, and I'm usually pretty occupied.
I do think that the testing progression you're describing is reasonable. You want to·make sure that you know how·to get CO2 readins·from the sensor before you start wondering about how to integrate it (hardware and software) into your·full setup. Is there really no sample software for that sensor? I'm sure Tracy can help, and if not, the·Parallax folks should be able to come up with something helpful.
Did you get your·L2 certification? Congratulations!
I·do think it's a great idea to have the team watch/help out at a launch. What's a K350? I've never heard of it, though I guess with all of the new Cesaronis out there, there are a lot of motors I don't know. I flew the XBee-MAWD telemetry device with Propeller-based receiver on Saturday, on a J350, successfully for the 10th straight flight. I've also flown an XBee-GPS rocket, and got good data from that. I've·just ordered newer boards for that setup - I expect to have regular GPS going this year, and hope to program a Propeller-based receiver for that as well.
·· You've had good success with that rocket... 10 straight launches and (almost?) nary a CATO. You did had a close call with·a landing·last year, didn't you? Sounds like you have the telemetry dialed in. I meant J350, not K350 (it's an Aerotech, not a Cessaroni.)
I agree with you: there certainly must be program code for the CO2 sensor on the forums. The Rocketeers will need to dig deeper into the forums to find it. It's there to be found, I'm sure. Welocme to the Rocket Team!
Please contact your teammates-- by e-mail and here on the forum-- and have them locate program code for the CO2 sensor on the forums before the sensor arrives in a day or two. Also ask them to downlaod and print out the doumentation (schematics, pin-outs, tech specs, etc.) and add it to their team binder. Let's have a program for ready when the sensor arrives. As Team Captain you will have to explain to the new team members:
1) Where to look (on the forums) and,
2) What exactly they are looking for. Maybe show them a short sample program for reference...?
Please contact your teammates-- by e-mail and here on the forum-- and have them locate program code for the CO2 sensor on the forums before the sensor arrives in a day or two. Also ask them to downlaod and print out the doumentation (schematics, pin-outs, tech specs, etc.) and add it to their team binder. Let's have a program for ready when the sensor arrives. As Team Captain you will have to explain to the new team members:
1) Where to look (on the forums) and,
2) What exactly they are looking for. Maybe show them a short sample program for reference...?
Justin said...
Dylan,
On the graph wouldnt the most currrent data come from December and not July since July is in the middle of the year and December is at the end of the year?
....................I need to work on my data analyses skills lol ..... Sorry about that.. Ill be able to only change that tomorrow morning sorry..........
Wow, a lot happens in one day!
You have located numbers for atmospheric CO2 (which is also inhaled CO2, right?), and you have numbers for exhaled CO2.
-- atmospheric (inhaled) in the neighborhood of 385 to 395 ppm (0.0385% to 0.0395%)
-- exhaled in the neighborhood of 4% to 6%. (40000 to 60000 ppm)
There is no exact right answer and I want to leave it as a range of values.
I'd like to come back to the graph... more homework...
>> 3) ANSWER TO QUESTION #3: Find a sensitivity curve for the Parallax sensor, and
>> compare it with atmospheric CO2 levels.
>> Andrew: Posted the sensitivity curve graph to the forum (see above.)
OR repeated here...
Look at it. What does it mean? This is a graph of how the EMF(mV) output from the raw sensor depends on the ppm concentration of CO2. Do you know what EMF(mV) stands for? (The output from the Parallax circuit board at test point TP1 will be higher, also EMF, because of amplification, but we'll get into that later).
From the graph, what will be the EMF(mV) output of the raw sensor be when exposed to 1000ppm CO2? 500 ppm? 10000ppm?
How about CO2 in the atmospheric range of 385 to 395 ppm?
How about CO2 in the exhaled range of 40000 to 60000 ppm?
(These last two are not necessarily easy to answer, why?)
What the inset box doing there, the one that shows the red and black lines with squares, circles, triangles and x's?
Here is a pretty and informative animation that shows CO2 concentrations globally through time as a color map. These were made by remote sensing from satellites.
Homework from Tracy Allen – May 26, 2010 ·
Find a sensitivity curve for the Parallax sensor, and compare it with atmospheric CO2 levels. ·
1)····· QUESTION: What does it mean? ·
ANSWER: (From Dr. Allen) – This is a graph of how the EMF (mV) output from the raw sensor depends on the ppm concentration of CO2. Do you know what EMF (mV) stands for? (The output from the Parallax circuit board at test point TP1 will be higher, also EMF, because of amplification, but we'll get into that later). ·
ANSWER (From the Rocketeers): ‘EMF’ stands for electromotive force. EMF is “Force that makes an electrical current flow, or voltage.” – www.yourwebassistant.net/glossary/e3.htm · ·
2)····· QUESTION: From the graph, what will be the EMF (mV) output of the raw sensor be when exposed to 1000ppm CO2? 500 ppm? 10000ppm? ·
········· ANSWER A: 1000 ppm = 304 mV · ·
········· ANSWER B: 500 ppm = 319 mV ·
········· ANSWER C: 10,000 ppm = 265 mV · ·
3)····· QUESTION: How about CO2 in the atmospheric range of 385 to 395 ppm? ·
ANSWER: 385-395 ppm is approximately 324-326 mV · ·
4)····· QUESTION: How about CO2 in the exhaled range of 40000 to 60000 ppm? ·
ANSWER: ·40,000-60,000 ppm is approximately 234-241 mV · ·
5)····· QUESTION: These last two—40000 to 60000 ppm—are not necessarily easy to answer, why? ·
ANSWER: This question was not as easy to answer because these values (40,000-60,000 ppm) were not on the “sensitivity curve” graph. We had to “interpolate” the answers by extending the graph lines. Attached is a copy of the graph we made. · ·
6)····· QUESTION: What’s the inset box doing there, the one that shows the red and black lines with squares, circles, triangles and x's? ·
ANSWER: The inset box has symbols that represent concentrations of different gases, all on the same graph (carbon dioxide, carbon monoxide, methane… and ethanol, which is a liquid/ alcohol). · OUR QUESTION: Why is ethanol represented on a graph with gases? We assume it’s because the same graph is used to calibrate C0, C02, CH4, and ethanol sensors. Is our assumption correct? ·
Thanks! ·
The Rocketeers · ·
Tracy Allen
Today Mr. Kibler and I *attempted* to wire a Parallax CO sensor module to a fresh BoE, also from Parallax. Bottom line, it smoked.. We do not think we fried it though.
I will try to describe the setup as best I can...
The CO's PIN's were...
ALR: Alarm, HSW: Heat switch from microcontroller,+5V: +5 VDC power, GND: Ground...
The CO sensor was plugged in directly into the breadboard so that each PIN had its own bus.... BUS #1 ( #= Means that nothing was in that slot)( Different slots are separated by -'s)
ALR-#-WIRE (A)-#-#
BUS #2
HSW-#-WIRE (B)-#-#
BUS #3
+5V-#-WIRE (C)-#-#
BUS #4
GND-#-WIRE (D)-#-#
The pins were wired from their corresponding wires up to the PIN I/O that were going vertical touching the breadboard (If you don't know what the BoE looks like, look of Board of Education on the Parallax website.).
If you have a BASIC stamp editor and a free BoE it would be great if you could try this.
It smoked.... If I remember correctly, the program counted down for 10 seconds to *PURGE* it.
Right after it counts down from 90. At about 87 it starts to smoke.
In the program it states that in the PURGE stage ( the 10 seconds) It sends 5V to the sensor to *Evaporate* any thing inside the sensor like unwanted chemicals. Im not sure if this was just the evaporation or if it was really frying.
Tomorrow I will have a picture posted to show you a better description of our situation...
***Mr. Kibler, please bring your camera to school tomorrow!!***
Awaiting your reply,
Dylan Landry
Extrapolation is filling in data points beyond the data that you have (extending the data). While interpolation is filling in data points between the data that you already have.
·· Thanks for the update and for the reminder to bring my camera in tomorrow. We'll take a photo of how the CO sensor is wired on the breadboard for·everyone to see. I also hope we didn't "fry" it but I don't think smoke coming·from around the CO sensor was necessarily a good thing...! As you saw, the sensor didn't output data: it simply activates an "alarm" (buzzer, sirer, flshing LED, etc.)·when the CO concentration reaches a certain level. We'dlike to program the CO2 sensor to output data (CO2 in ppm.)
ALL ROCKETEERS,
·Please look at Dr. Allen's "homework assignment for the day" (above) and work together on-line to answer the questions he's asked you. It would be nice to see this done when I get to school in the morning so we can figure out programming the CO sensor·while we wait for the CO2 sensor to arrive.
What IS the difference between 'interpolation' and 'extrapolation'? Did we interpolate or extrapolate the answers today? Either way,
·· Also tonight, please search the Parallax forums and locate programs to make the CO sensor work (not the CO2 sensor; that comes next week.) The sample code that comes as documentation with the CO sensor is a good start but we'd like alternatives.
SEAN: Good answer! We extrapolated data today (not interpolated) because we didn't have the lower data points. What are the answers to the other questions...?
Would Justin and I still have to fill those questions out for Dr. Allen? We have the answer sheet completed and saved to your laptop, dont we? I wasn't there for the whole completion but it looked like you guys finished it during U.A.... Will you be submitting it today? I would like to know this so I can reserve some time later tonight to complete it.
"What is the output in mV of the power supply for your BASIC Stamp?"
Answer: (Question: Do you mean the range of how much Volts is required to run it? The output to run the CO2 sensor? The output varies between what you are using as a sensor.)
"Look up the difference between "interpolate" and "extrapolate"."
Answer: A.) If someone says," We must interpolate the data." That means that they have to *add* data.
B.) If someone says," We must extrapolate the data." That means we must add data that we already knew in the first place.
"Do you think this sensor would be a good one to detect the level of methane? Why or why not?"
Answer: A.) If we where to want to detect methane, then the most efficient and proper way would to buy a methane sensor. I personally would not risk the option of failure.
B.) If we were to want to detect methane, and be in the possession of a CO sensor, I would want it to be professionally done with proper parts and equipment.
BUT
A CO sensor is *possible* through certain calibrations and tweaking sense methane. It wouldn't be *good* because of the unreliabilities of the amount of tweaking. But yes, it is possible.
Dylan Landry
Post Edited (Dylan Landry) : 5/26/2010 10:32:20 PM GMT
Below are links for code and schematics for the CO sensor. Consider putting the sensor on a stand-alone board, if we have one, to make things less complicated.
2a) I would have to agree with Sean that we have extrapolated the data because we extended the graph instead of filling it in.
3.)·I think that it would be better to use a CO sensor instaed of a CO2 sensor for the fact that they are designed to measure their own different gas. Could we use a CO2 sensor to measure methane? I think that it would be possible, but the data would most likely be unreliable because it came from a different sensor that wasn't created to measure that specific gas.
If you are talking about the sample code, go to Parallax.com, then store, sensors, gas, CO sensor module, and near the bottom there will be all the links you are looking for.
P.S. If you are looking for a career in Robotic Engineering go to http://www.wpi.edu/Academics/Majors/RBE/ It was the first college to even have a Robotics Engineering programs. Also, its in Mass!!
I know where I'm going!! Sorry just had to say that.
Dylan
Post Edited (Dylan Landry) : 5/26/2010 11:45:57 PM GMT
Do you think this sensor would be a good one to detect the level of methane? Why or why not? · I agree with Justin. No because if we wanted to measure methane we could just buy a methane sensor and a methane sensor is made to measure methane. If we wanted the most accurate results personally I would use the methane sensor because I believe that it would be the most accurate. ·
Attached are pictures of how the CO sensor is wired on a stand-alone BOE. We are using the sample program that came with the documentation (On the Parallax products "Sensors" link.) See our comments above that describe what happened yesterday. What are everyone's thoughts?
Comments
On the data for the CO2 concentrations at different altitudes, why do some intervals of kilometers not have a corresponding CO2 level? Also, how did you find the CO2 concentraions at each level, since the graphs measured the CO2 levels by month?
We took the most current data we could find which was the July data. The reason why some do not have readings, I am not sure. After a long, long search this was the only relevant data we could find.
On the graph wouldnt the most currrent data come from December and not July since July is in the middle of the year and December is at the end of the year?
··· I agree with Sylvie. One of your next steps is to read the documentation for the CO2 sensor. Andrew and·Dylan have already downloaded it from the Parallax website, printed it out, and put it in their team binder. While we're waiting for the sensor to arrive you should also find some preliminary program code for the CO2 sensor (search the forums) so·you can, as Sylvie suggests, "do some testing."
Sylvie,
··· We do have more than one BOE/ BS2. We can put the new·CO2 sensor on it as a "stand-alone" prototype unit. Once the Rocketeers have it up and running·with a simple program we can·move it over to·last year's·MAWD-BOE and (re)program the·MAwhole thing. Does that seem like a logical progression?
Last year's team members are explaining how the rocket, payload bay, and payload (the ASP/ MAWD-BOE) are integrated to new team members. If time allows I'd like to take the team to a local club launch and launch·my·6" diameter L-2 rocket (without the ASP payload) on a K-350. Then they'll see how the subsystems are integrated.
I say, "If time allows" because my wife was hit from behind by a car while she was·bicycling to work in October,·just after the ARLISS launch. She was in critical care at Dartmouth Medical Center for weeks and in the hospital for months. Her leg bones were shattered (she has titanium rods in them now); her pelvis was broken in three places (she has metal plates); she was catapulated head-first into a tree and her vertebrae "exploded" (burst fractured); she had blood clots in her lungs; and she was unconscious,among other things. Tending to her and her health were, and continue to be, a priority, and "free" time has·come at a premium. She's lucky to be alive and not vegetative.
Just so you and Tracy know, my program skills are not that strong and the schematics confuse me.·That's why I appreciate your help. We can get·the CO2 sensor·up and going if you guys can help with the higher-order programming.
You should really come out to Black Rock and launch with us in September! (September 14-18.)
Best regards,
Mark
I'd love to comeout to Black Rock, and I'll try, but that is the second week of the school year, and I'm usually pretty occupied.
I do think that the testing progression you're describing is reasonable. You want to·make sure that you know how·to get CO2 readins·from the sensor before you start wondering about how to integrate it (hardware and software) into your·full setup. Is there really no sample software for that sensor? I'm sure Tracy can help, and if not, the·Parallax folks should be able to come up with something helpful.
Did you get your·L2 certification? Congratulations!
I·do think it's a great idea to have the team watch/help out at a launch. What's a K350? I've never heard of it, though I guess with all of the new Cesaronis out there, there are a lot of motors I don't know. I flew the XBee-MAWD telemetry device with Propeller-based receiver on Saturday, on a J350, successfully for the 10th straight flight. I've also flown an XBee-GPS rocket, and got good data from that. I've·just ordered newer boards for that setup - I expect to have regular GPS going this year, and hope to program a Propeller-based receiver for that as well.
Paul·
·· You've had good success with that rocket... 10 straight launches and (almost?) nary a CATO. You did had a close call with·a landing·last year, didn't you? Sounds like you have the telemetry dialed in. I meant J350, not K350 (it's an Aerotech, not a Cessaroni.)
I agree with you: there certainly must be program code for the CO2 sensor on the forums. The Rocketeers will need to dig deeper into the forums to find it. It's there to be found, I'm sure. Welocme to the Rocket Team!
Please contact your teammates-- by e-mail and here on the forum-- and have them locate program code for the CO2 sensor on the forums before the sensor arrives in a day or two. Also ask them to downlaod and print out the doumentation (schematics, pin-outs, tech specs, etc.) and add it to their team binder. Let's have a program for ready when the sensor arrives. As Team Captain you will have to explain to the new team members:
1) Where to look (on the forums) and,
2) What exactly they are looking for. Maybe show them a short sample program for reference...?
Thanks,
Mr. Kibler
Mr. Kibler
Please contact your teammates-- by e-mail and here on the forum-- and have them locate program code for the CO2 sensor on the forums before the sensor arrives in a day or two. Also ask them to downlaod and print out the doumentation (schematics, pin-outs, tech specs, etc.) and add it to their team binder. Let's have a program for ready when the sensor arrives. As Team Captain you will have to explain to the new team members:
1) Where to look (on the forums) and,
2) What exactly they are looking for. Maybe show them a short sample program for reference...?
Thanks,
Mr. Kibler
Mr. Kibler
....................I need to work on my data analyses skills lol
My mistake... AND MIKES lol.
You have located numbers for atmospheric CO2 (which is also inhaled CO2, right?), and you have numbers for exhaled CO2.
-- atmospheric (inhaled) in the neighborhood of 385 to 395 ppm (0.0385% to 0.0395%)
-- exhaled in the neighborhood of 4% to 6%. (40000 to 60000 ppm)
There is no exact right answer and I want to leave it as a range of values.
I'd like to come back to the graph... more homework...
>> 3) ANSWER TO QUESTION #3: Find a sensitivity curve for the Parallax sensor, and
>> compare it with atmospheric CO2 levels.
>> Andrew: Posted the sensitivity curve graph to the forum (see above.)
OR repeated here...
Look at it. What does it mean? This is a graph of how the EMF(mV) output from the raw sensor depends on the ppm concentration of CO2. Do you know what EMF(mV) stands for? (The output from the Parallax circuit board at test point TP1 will be higher, also EMF, because of amplification, but we'll get into that later).
From the graph, what will be the EMF(mV) output of the raw sensor be when exposed to 1000ppm CO2? 500 ppm? 10000ppm?
How about CO2 in the atmospheric range of 385 to 395 ppm?
How about CO2 in the exhaled range of 40000 to 60000 ppm?
(These last two are not necessarily easy to answer, why?)
What the inset box doing there, the one that shows the red and black lines with squares, circles, triangles and x's?
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Tracy Allen
www.emesystems.com
airs.jpl.nasa.gov/story_archive/CO2_Increase_Sep2002-Jul2008/Media/Airs_Carbon_Dioxide11.wmv
airs.jpl.nasa.gov/
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Tracy Allen
www.emesystems.com
·
Find a sensitivity curve for the Parallax sensor, and compare it with atmospheric CO2 levels.
·
1)····· QUESTION: What does it mean?
·
ANSWER: (From Dr. Allen) – This is a graph of how the EMF (mV) output from the raw sensor depends on the ppm concentration of CO2. Do you know what EMF (mV) stands for? (The output from the Parallax circuit board at test point TP1 will be higher, also EMF, because of amplification, but we'll get into that later).
·
ANSWER (From the Rocketeers): ‘EMF’ stands for electromotive force. EMF is “Force that makes an electrical current flow, or voltage.” – www.yourwebassistant.net/glossary/e3.htm
·
·
2)····· QUESTION: From the graph, what will be the EMF (mV) output of the raw sensor be when exposed to 1000ppm CO2? 500 ppm? 10000ppm?
·
········· ANSWER A: 1000 ppm = 304 mV ·
·
········· ANSWER B: 500 ppm = 319 mV
·
········· ANSWER C: 10,000 ppm = 265 mV
·
·
3)····· QUESTION: How about CO2 in the atmospheric range of 385 to 395 ppm?
·
ANSWER: 385-395 ppm is approximately 324-326 mV
·
·
4)····· QUESTION: How about CO2 in the exhaled range of 40000 to 60000 ppm?
·
ANSWER: ·40,000-60,000 ppm is approximately 234-241 mV
·
·
5)····· QUESTION: These last two—40000 to 60000 ppm—are not necessarily easy to answer, why?
·
ANSWER: This question was not as easy to answer because these values (40,000-60,000 ppm) were not on the “sensitivity curve” graph. We had to “interpolate” the answers by extending the graph lines. Attached is a copy of the graph we made.
·
·
6)····· QUESTION: What’s the inset box doing there, the one that shows the red and black lines with squares, circles, triangles and x's?
·
ANSWER: The inset box has symbols that represent concentrations of different gases, all on the same graph (carbon dioxide, carbon monoxide, methane… and ethanol, which is a liquid/ alcohol).
·
OUR QUESTION: Why is ethanol represented on a graph with gases? We assume it’s because the same graph is used to calibrate C0, C02, CH4, and ethanol sensors. Is our assumption correct?
·
Thanks!
·
The Rocketeers
·
·
Tracy Allen
What does "mV" stand for? (Just checking!) What is the output in mV of the power supply for your BASIC Stamp?
Look up the difference between "interpolate" and "extrapolate". What assumptions must you make in either case?
Do you think this sensor would be a good one to detect the level of methane? Why or why not?
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Tracy Allen
www.emesystems.com
Today Mr. Kibler and I *attempted* to wire a Parallax CO sensor module to a fresh BoE, also from Parallax. Bottom line, it smoked.. We do not think we fried it though.
I will try to describe the setup as best I can...
The CO's PIN's were...
ALR: Alarm, HSW: Heat switch from microcontroller,+5V: +5 VDC power, GND: Ground...
The CO sensor was plugged in directly into the breadboard so that each PIN had its own bus....
BUS #1 ( #= Means that nothing was in that slot)( Different slots are separated by -'s)
ALR-#-WIRE (A)-#-#
BUS #2
HSW-#-WIRE (B)-#-#
BUS #3
+5V-#-WIRE (C)-#-#
BUS #4
GND-#-WIRE (D)-#-#
The pins were wired from their corresponding wires up to the PIN I/O that were going vertical touching the breadboard (If you don't know what the BoE looks like, look of Board of Education on the Parallax website.).
http://www.parallax.com/Portals/0/Downloads/docs/prod/boards/28150-BOE-Serial-v2.0.pdf
The following wires where hooked up to the corresponding PIN I/Os...
WIRE A: P1
WIRE B: P0
WIRE C: Vdd
WIRE
We were just following the http://www.parallax.com/Portals/0/Downloads/docs/prod/sens/27931_CO_GasSensor.zip (sample code provided by Parallax)..
I experimented a bit after this.
If you have a BASIC stamp editor and a free BoE it would be great if you could try this.
It smoked.... If I remember correctly, the program counted down for 10 seconds to *PURGE* it.
Right after it counts down from 90. At about 87 it starts to smoke.
In the program it states that in the PURGE stage ( the 10 seconds) It sends 5V to the sensor to *Evaporate* any thing inside the sensor like unwanted chemicals. Im not sure if this was just the evaporation or if it was really frying.
Tomorrow I will have a picture posted to show you a better description of our situation...
***Mr. Kibler, please bring your camera to school tomorrow!!***
Awaiting your reply,
Dylan Landry
Extrapolation is filling in data points beyond the data that you have (extending the data). While interpolation is filling in data points between the data that you already have.
Still working on the other questions,
Sean
·· Thanks for the update and for the reminder to bring my camera in tomorrow. We'll take a photo of how the CO sensor is wired on the breadboard for·everyone to see. I also hope we didn't "fry" it but I don't think smoke coming·from around the CO sensor was necessarily a good thing...! As you saw, the sensor didn't output data: it simply activates an "alarm" (buzzer, sirer, flshing LED, etc.)·when the CO concentration reaches a certain level. We'dlike to program the CO2 sensor to output data (CO2 in ppm.)
ALL ROCKETEERS,
·Please look at Dr. Allen's "homework assignment for the day" (above) and work together on-line to answer the questions he's asked you. It would be nice to see this done when I get to school in the morning so we can figure out programming the CO sensor·while we wait for the CO2 sensor to arrive.
What IS the difference between 'interpolation' and 'extrapolation'? Did we interpolate or extrapolate the answers today? Either way,
Good work!
Mr. Kibler
·· Also tonight, please search the Parallax forums and locate programs to make the CO sensor work (not the CO2 sensor; that comes next week.) The sample code that comes as documentation with the CO sensor is a good start but we'd like alternatives.
SEAN: Good answer! We extrapolated data today (not interpolated) because we didn't have the lower data points. What are the answers to the other questions...?
Would Justin and I still have to fill those questions out for Dr. Allen? We have the answer sheet completed and saved to your laptop, dont we? I wasn't there for the whole completion but it looked like you guys finished it during U.A.... Will you be submitting it today? I would like to know this so I can reserve some time later tonight to complete it.
Awaiting your Response,
Dylan Landry
"What does "mV" stand for?"
Answer: Millivolts...
"What is the output in mV of the power supply for your BASIC Stamp?"
Answer: (Question: Do you mean the range of how much Volts is required to run it? The output to run the CO2 sensor? The output varies between what you are using as a sensor.)
"Look up the difference between "interpolate" and "extrapolate"."
Definitions
Interpolate: "To insert between other things or parts." Source: http://www.merriam-webster.com/dictionary/interpolate
Extrapolate: "to project, extend, or expand (known data or experience)..." Source: http://www.merriam-webster.com/dictionary/extrapolate
"What assumptions must you make in either case?"
Answer: A.) If someone says," We must interpolate the data." That means that they have to *add* data.
B.) If someone says," We must extrapolate the data." That means we must add data that we already knew in the first place.
"Do you think this sensor would be a good one to detect the level of methane? Why or why not?"
Answer: A.) If we where to want to detect methane, then the most efficient and proper way would to buy a methane sensor. I personally would not risk the option of failure.
B.) If we were to want to detect methane, and be in the possession of a CO sensor, I would want it to be professionally done with proper parts and equipment.
BUT
A CO sensor is *possible* through certain calibrations and tweaking sense methane. It wouldn't be *good* because of the unreliabilities of the amount of tweaking. But yes, it is possible.
Dylan Landry
Post Edited (Dylan Landry) : 5/26/2010 10:32:20 PM GMT
Below are links for code and schematics for the CO sensor. Consider putting the sensor on a stand-alone board, if we have one, to make things less complicated.
Sample Code: www.parallax.com/Portals/0/Downloads/docs/prod/sens/27931_CO_GasSensor.zip
Sample Schematics: www.parallax.com/Portals/0/Downloads/docs/prod/sens/COGasSensorModule_ASchematic.pdf
If you look 1, 2, 3, 4, 5, yes *6* posts above yours that is what we did.
Dylan
1.) mV stands for millivolts
1a) The output of the power supply would be 1.22 mV (if im reading this site correctly.) http://www.parallax.com/dl/docs/prod/appkit/ltc1298.pdf
2.) Interpolate-"To insert or introduce between other elements or parts" - http://www.thefreedictionary.com/interpolate
····
Extrapolate- "To infer or estimate by extending or projecting known information" - http://www.thefreedictionary.com/extrapolate
2a) I would have to agree with Sean that we have extrapolated the data because we extended the graph instead of filling it in.
3.)·I think that it would be better to use a CO sensor instaed of a CO2 sensor for the fact that they are designed to measure their own different gas. Could we use a CO2 sensor to measure methane? I think that it would be possible, but the data would most likely be unreliable because it came from a different sensor that wasn't created to measure that specific gas.
It won't let me open the link to the CO gas sensor. Is there another way I could access it?
Justin
If you are talking about the sample code, go to Parallax.com, then store, sensors, gas, CO sensor module, and near the bottom there will be all the links you are looking for.
P.S. If you are looking for a career in Robotic Engineering go to http://www.wpi.edu/Academics/Majors/RBE/ It was the first college to even have a Robotics Engineering programs. Also, its in Mass!!
Dylan
Post Edited (Dylan Landry) : 5/26/2010 11:45:57 PM GMT
Millivolts
What is the output in mV of the power supply for your BASIC Stamp?
http://www.parallax.com/Store/Microcontrollers/BASICStampDevelopmentBoards/tabid/137/CategoryID/12/List/0/SortField/0/Level/a/ProductID/125/Default.aspx. I believe that this is our basic stamp (please correct me if I am wrong), but I can't seem to find the amount of volts. Maybe I just not looking for the right thing or I am not looking in the right place. But if you could take a look at this and see if you could find it that would be great.
Do you think this sensor would be a good one to detect the level of methane? Why or why not?
·
I agree with Justin. No because if we wanted to measure methane we could just buy a methane sensor and a methane sensor is made to measure methane. If we wanted the most accurate results personally I would use the methane sensor because I believe that it would be the most accurate.
·
Both links are working for me. If you still can't access them, I'll download and upload them somewhere else for you if you want.
Dylan and Mr. Kibler