This is my example code for the STM32F4 Discovers using the RTOS ChibiOS.
- Chibios 2.5.0+ (or a recent development snapshot)
- arm toolchain (e.g. arm-none-eabi from summon-arm)
- serial over USB console
- PWM initialization and control
- ADC measuring, continuous and single scan
- background blinker thread
- code structured into separate files
- edit the Makefile and point "CHIBIOS = ../../chibios" to your ChibiOS folder
- make
- connect the STM32F4 Discovery with both USB connectors
- flash the STM32F4: st-flash write build/ch.bin 0x8000000
- use your favorite terminal programm to connect to the Serial Port (/dev/ttyACM0 for me, probably COM1 on Windows)
- help
- exit
- info
- systime
- mem
- threads
- toggle 1/2/3/4 (toggles #led, short: t)
- blinkspeed #speed (changes blinker period to #speed ms, short: bs)
- cycle #duty (changes the duty cycle of PWM1 to #duty, short: c)
- ramp #from #to #step [delay] (creates a ramp for PWM1 with the given parameters, short: r)
- measure (measures 16384 analog samples on pin PC1 and prints the first and the average, short: m)
- measureAnalog (measures 16384 samples and converts the average to Volts, short: ma)
- measureDirect (measures 16384 samples and prints them all, short: md)
- measureContinuous (starts a background analog conversion, short: mc)
- readContinuousData (prints what has been collected by the background conversion, short: rd)
- stopContinuous (stops the analog conversion, short sc)
Neither am I a good C programmer nor do I have extensive knowledge about ChibiOS, the STM32F4 or uCs in general. I wrote this code to make myself familiar with the STM32F4 Discovery and I figured ChibiOS was a usefull tool. From my POV the code is not that bad, but your opinion may differ. In that case, please don't laugh at my code but provide constructive criticism. I just realized: I'm no pro at Git, Github and Markdown either...
Since I started from the USB-CDC code example from ChibiOS which is GPLv3, I think I am forced to release this code under GPLv3 though I don't care what you do with the code. I asked Giovanni and he said "there is not much meat" in it anyways.