Props in Class
deSilva
Posts: 2,967
A first cycle of my class about using micro controllers will come to an end tomorrow, Participants had been programmers, with elctronics background, but either from times long ago or of a very theoretical kind.
What have I learned for the next cycle?
(A) We started with 8 Edu-Kits. These Kits are extremely fine, and even affordable @ 20 pcs. They released me from compiling a quite complex shopping list. I additionally just needed a few CMOS SSI chips to start with (for pre-investigation of I/O behavior without endangering the Prop ), some low cost voltage meters, wire cutters, tweezers, and turnscrews completed the equipment.
(B) It all takes longer than you think, getting acquainted with the breadboards, many misunderstandings, errors. But could be checked and fixed within the class, comparing what worked against what not worked.
In the first place you should not expect that the installation of the Propeller Kit and the USB driver will work eight times. We succeeded after half an hour, but it remained unclear what the issues really had been...
(C) An oscilloscope should be used by the teacher , preferrable an USB box the output of which could be beamed through the PC. To have one for each student was out of the question for budget reasons, but I also doubt it will improve the situation in a beginner's group
(D) Chapter 1 of the Manual turned out to be unreadable. Chapter 2 and 3 were fine for self study. But the persons that started from the beginning dispaired. Lots of detailed technical information about clocks and crystals... They started WITHOUT EEPROM and crystals in the first place. The "piece de resistance" finally was the description of the interleaved character set.
(E) After six weeks now: Two dead Props (of eight) :-(
But lots of parts the usage of which still to be discovered for after class projects
Post Edited (deSilva) : 10/9/2007 10:30:54 PM GMT
What have I learned for the next cycle?
(A) We started with 8 Edu-Kits. These Kits are extremely fine, and even affordable @ 20 pcs. They released me from compiling a quite complex shopping list. I additionally just needed a few CMOS SSI chips to start with (for pre-investigation of I/O behavior without endangering the Prop ), some low cost voltage meters, wire cutters, tweezers, and turnscrews completed the equipment.
(B) It all takes longer than you think, getting acquainted with the breadboards, many misunderstandings, errors. But could be checked and fixed within the class, comparing what worked against what not worked.
In the first place you should not expect that the installation of the Propeller Kit and the USB driver will work eight times. We succeeded after half an hour, but it remained unclear what the issues really had been...
(C) An oscilloscope should be used by the teacher , preferrable an USB box the output of which could be beamed through the PC. To have one for each student was out of the question for budget reasons, but I also doubt it will improve the situation in a beginner's group
(D) Chapter 1 of the Manual turned out to be unreadable. Chapter 2 and 3 were fine for self study. But the persons that started from the beginning dispaired. Lots of detailed technical information about clocks and crystals... They started WITHOUT EEPROM and crystals in the first place. The "piece de resistance" finally was the description of the interleaved character set.
(E) After six weeks now: Two dead Props (of eight) :-(
But lots of parts the usage of which still to be discovered for after class projects
Post Edited (deSilva) : 10/9/2007 10:30:54 PM GMT
Comments
About the software: it is amazing how computers can be fo fickle (though they have the same software)
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Sorry, but you sound like a father, asking in the evening:" So I see the boy again bruised his knees! What did he do all the day?"
The precaution is simple: Buy more Props
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
No, it's people like you and me
But it is in Hamburg, Germany
And: "Man sprikt Deutsch"
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
The explanation in the wikipedia is wrong BTW.
Baking powder generally contains Natriumhydrogencarbonate, but for "Amerikaner" (= Black and White Cookies)
Ammoniumhydrogencarbonate is used, which during the baking process will issue ammonia:
NH4HCO3 --> NH3 + H2O + CO2
Thus they were called "Ammoniakaner" for a short time, easily leading to "Amerikaner"
Post Edited (deSilva) : 10/10/2007 2:01:48 AM GMT
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Can you keep us informed when your next courses start and what you will focus on?
I personally would be interested in learning some basic electronic concepts because I am very reluctant to just wire up things and see what happens (in contrary to programming where it is usually safe to just try out things). Maybe that is why I havn't killed any prop so far - knock on wood.
Examples, what I'd be interested in:
1. That sigma delta AD-conversion thing with a microphone... I have wired everything just like the demoboard, but get very scratchy funny sounding echoes when I try Beau Schwabe's Microphone to headphone object.
http://forums.parallax.com/forums/default.aspx?f=25&m=217193
2. Some knowledge about audio generation. How do I get Multiple notes out of one speaker, how do I generate a sawtooth or a sine wave in assembler.
3. How do I wire up my IR-Led to control my Camera over greater distances than 10 Centimeters with the IR-Object.
(...) and all these things that you shoudn't try at home, if you don't know what you are doing.
I am using Demo boards to keep hardware setup time to minimum, and get quicker to the fun stuff.
This semester we are using the Hydra text, though it was backordered at the start of the semester and we spent 4 weeks doing some of the PEK labs with the demo board (actually worked out very well!).
I got them started with video early so they could use it in projects and such.
We've done a couple long projects - one was to make a controllable tone generator using Spin - They had to tweak the code to find get the frequency right, and they found the limits of spin and WAITCNTS. The video had to display the correct frequency being produced. From this they had to draw their schematics of what exactly was needed for prop hardware and layout a PCB (I'll select one to have produced). This expored using mutiple cogs too (one to watch the tone control buttons and display, one to produce the tone)
The next project was to use a 74xx165 shift register and write spin code to shift in a byte of data serially. They had one brainstorming day-session to discuss how the 165 worked, how to interface, come up with psuedo-code that should do the trick, etc. Then spent several sessions making it work. This was brought about by having a lesson the NES controllers from the hydra text. They had to roll their code into an object.
They have long term outstanding participation points to discuss infromation they see in forums and to select one thing they see on forums/object exchange to explore and demonstrate on their own. Hi Guys if you see this!
All in all, I'm having fun teaching with the prop and using this text and Andy's labs, and I really enjoy not having to spend 2 months just discussing dozens of registers in 8051/AVR/PIC style controllers and be able to start interfacing and controlling quickly with flair!
-Martin
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
StampPlot - GUI and Plotting Software
Southern Illinois University Carbondale, Electronic Systems Technologies
Post Edited (Martin Hebel) : 10/11/2007 12:05:59 AM GMT
I bought a proto board for my project, did all kinds of things to it, wasn't that careful about static, and mine still works! go figure.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
The more I know, the more I know I don't know.· Is this what they call Wisdom?
The basic class is 6 x 2.5 hours, lot of time lost for not done homework or having been off the last session
They start from the beginning, and are assumed to learn Propeller Tool and SPIN from the Manual, which is quite doable for people with a programmer's background. We in fact have a stronger electronics focus than I had intended., but not much time to do it thoroughly.
I chose a solderless breadboard for three reasons.
- Soldering was out!
- I wanted them to be really close to the hardware
- Budget was limited to €100 per person
I was aware of the time consuming issues with breadboards, but they turned out being not so relevant.
In fact the next two classes will use presoldered "modules" similar to the things Parts-Man does, but for breadboards only. Someone - maybe even Franz - posted a link to a supplier ( www.conelek.de ) where such parts are available, but one can make them for 10% of their price. So configuring a "board" is just plugging in 3 or 4 "modules" (power, Video, EEPROM/chrystal) - or 5 or 6.
An "advanced" class will follow in 2008
Post Edited (deSilva) : 10/10/2007 2:27:15 AM GMT
Thanks for the input, fun stuff!
-Martin
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
StampPlot - GUI and Plotting Software
Southern Illinois University Carbondale, Electronic Systems Technologies
(1) This being a 74HC00, obviously.
Then we discuss caps and make an oscillator out of two (or three) HC00.
The other two chips used are a 74HC4040 to divide that clock and a 74HC42 BCD-10 decoder. The first afternoon will stop with each one having built the most important part of a computer: a sequencer! The rest is trivia
(2) If we had more time we would also use a HC164 (SIPO) and a HC166 (PISO) or maybe their 5xx counterparts.
(3) There are also sidetracks walkable using a 74HC4049 which has some interesting output features, and can be used as a poor man's opamp.
(4) Another time consuming investigations could involve a Schmitt trigger (HC40106 e.g.). Additional latches or buffers are of minor relevance; latches can be discussed with the shift registers, and 4049 are fine buffers.
(5) Thinking about that: Yes, there should also be a section about "drivers", maybe ULN2803, but especially open drain applications - but this is no longer "logic"...
Post Edited (deSilva) : 10/11/2007 12:41:14 AM GMT
Martin,
This sounds like a terrific course! I commend you for having such an open minded approach.
I wish I had something like that to choose when I was doing my CS work!
Paul
When you get a chance (and inclination) I'd like to see your sequence of breadboard circuits.
F
(Everyone else, shhhhh. I am secretly getting deSilva to write his second opus, one small step at a time)·
Post Edited (Fred Hawkins) : 10/10/2007 11:22:09 PM GMT
I'm not sure what damaged brain cell I pulled the 74xx295 out of, I meant 74xx165.
-Martin
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
StampPlot - GUI and Plotting Software
Southern Illinois University Carbondale, Electronic Systems Technologies
The 295 does exist,very obsolete,and doesn't look like
it's available in HC, or HCT.
Best Regards
Ian
:- Good new rarely comes in a brown envelope.
Congratulations. There is a special place in heaven for teachers.
deSilva,
By the way, I am a deSilva fan. There aren't enough real characters in this world... and YOU are a real character.
I am trying to imagine a six week course, which includes both deSilva and the first three chapters of the user manual.
If a student can't get what he needs from "Propeller Guts," he/she isn't going to be able to absorb the user manual very comfortably.
Why not just stick to the lab notes?
As long as your course notes are complete, I guess it is ok, but I'm trying to imagine why there weren't 8 dead props, just to slow you down a little[noparse]:)[/noparse]
Rich