ChibiOS Free Embedded RTOS

Hi, I am also trying to use USB CDC with STM32L1xx-Discovery, without much success.

Am I right that there is a need of external oscillator for 8 MHz in order it to work
with discovery?

If so, can someone point me to a document which describes what resistors and capacitors needed for it to work ...

You should have cloned the dac-new tree instead of just dac.
https://github.com/mobyfab/ChibiOS/tree/dac-new

Let me suggest a little gem which I recently found https://github.com/bjornfor/stm32-test . Which have at least 2 sets of stm32libs for stm32l1xx and stm32f0xx. It also has make friendly settings, as well as unix friendly.

Original stm32 libs have a lot of letter case mixing, which is big ...

Well, it is as trivial as to send a word to a register at least in some cases, though care should be taken to stop relevant DMA and probably free timers if they used before. But it is hardware dependent, which ruins the idea of a general API. If you specify how function call should look like, I will ...

For those who might search through this thread.I find a problem: wrong DMA streams were set. Now it works.

Mobyfab merged my patches into his tree, see for more details
http://forum.chibios.org/phpbb/viewtopic.php?f=16&t=1196&p=13183#p13179

Great job Mobyfab!

I just compiled and ran testhal/STM32L1xx/DAC. According to digital multimeter it works, I will check it with a scope on Monday.

Giovanni, is it along ChibiOS lines to have a code which just sets a DAC output to a particular value, i.e. not a waveform? This is often handy in a ...

Not sure about what you mean, the DMA exchanges are usually triggered by peripherals.
This is where I am puzzled. I would expect that the DMA starts transfer to the DAC as soon as ask for conversion in the code,
but you are implying that I probably need to toggle/trigger one of the external pins ...

I would suggest to start from either of the directories in the
testhal/STM32F0xx
They have known to work code samples. You will just need to trace appropriate pins to the ones at your board.

Most importantly they have a proper Makefile which compiles, just fill it with needed extras.

To flash I use the following line

I work with stm32l1, but I thinkthe flashing directive is the same for stm32f0 as well.

I find that I cannot work with openocd reliably, but st-flash works.

Quick diff shows that they are identical in functionality. F1 part has a few extra related to DMA2 but otherwise they are the same.

Is there a condition to be met for DMA exchange to be started?