[Paparazzi-devel] Introduction, Q's about STM32 development

[Jake Stewart]

Hello Paparazzi list members!  I'm a microbiologist from Idaho (USA).  I have a 
basic electronics background with some experience with RC flying and a little 
bit with Atmega8 programming.  I'm very interested in using UAVs to collect 
unique biological samples from inaccessable areas like remote areas, high 
altitude areas, open seas, arial samples, etc..

Your project is amazingly impressive!  So much so that it is pretty 
intimidating to a non-expert such as myself.  I have a few questions about 
where to begin.  I've done a fair bit of reading on the project, but perhaps 
need some advice on getting started.  Feel free to let me know if I'm out of 
line, or reply off-list, or ignore any or all of my questions if it's something 
I should be able to figure out myself.

I am currently playing with STM32 VL Discovery boards from ST.  I got a 
handfull of them from Arrow for the insane price of $2.20 each! Link and 
datasheet...
http://components.arrow.com/part/detail/49099771S8561546N7728
http://download.siliconexpert.com/pdfs/2010/11/13/7/31/8/620/st_/manual/cd00277245.pdf

It's essentially a STM32F100B chip with all the pins exposed on headers, on a 
board with a STM32103 for USB programming support, a couple lights and buttons, 
and with all the voltage regulators and whatnot that you'd expect for a simple 
dev board.  I'm curious what I could do with such a cheap board.  I figure that 
they're essentially disposable for all intents and purposes, so no worries 
about going soldering iron crazy and trying to prototype some interesting 
circuits.

I'm curious about the extent that the code is tied to the hardware...
What hardware features are there beyond a proto/dev board that are necessary 
for the project?
Would it be possible to implement something on a cheap board like the one I 
mentioned?
Is the code dependent on any of the hardware on the LISA boards?
What are the memory requirements for the firmware?

I ask because I'm currently using Atollic in Windows with my board and haven't 
yet set up a linux environment/toolchain to work with.  Any tips or pointers to 
info on that would also be much appreciated, although I think I saw some info 
on that somewhere.  My only linux install at the moment is BT3.  Should I try 
with that or install debian/ubuntu?

I reallize these are all pretty noobish questions, but I just wanted to 
introduce myself and see if I couldn't make a contact or two who have done 
similar work or could easily give me some answers.

I plan to put some serious work into this project and think I have most of the 
tools needed.  Besides my $2.20 dev boards I have soldering irons, lot's of 
spare components, a few prototype boards, two o-scopes, multimeters, etc..  For 
the project I've gotten a 9DOF IMU (ST chips), a few pressure/barometer 
sensors, a differential pressure sensor for an airspeed tube, a Fastrax GPS 
module, and a couple generic RF serial modems (sub-G TI chip based).  I also 
have an electric plane, laptop, 3 small cameras, and a 900mhz video 
transmitter.  As far as I can tell I have everything to build a prototype UAV 
and just need to wire everything together and program it! Easy right? (kidding)

If running on different hardware platforms is not something easily done with 
the project I'm hoping I can put together a more basic program running a subset 
of the normal features.  One reason I'm thinking of this is that I need to do 
things on the extreme cheap side as I don't have a lot of confidence that a 
very high percentage of my planes would actually be returning due to the 
dangerous nature of what they would be doing.  Maybe I'm wrong there, but I 
don't envision a whole lot of my hardware returning to me and I'd be happy with 
a 50/50 crapshoot if I can keep the hardware within budget.

At the moment I'm hoping to use the components I've gotten for testing. Not 
sure I really even need a radio.
STM32VLDiscovery board - $2.20 (arrow)
9DOF IMU - $50 (pololu.com)
Fastrax GPS - $28 (mouser)
Cessna 182 (electric, 1.4m wingspan) - $130 (hobbyking)
--------------------
Total $210.20

So if I can get any sort of reasonable return rate (many missions would 
probably be pretty safe) I should be able to get samples for fairly cheap 
(<$500).  That should be much cheaper than collecting them by hand and open up 
a lot of areas that simply aren't accessable.  Am I crazy to think this might 
be possible?


-Jake