DAC driver for the STM32

[mobyfab]

Hi,

I am currently working on the DAC driver for the STM32F0/3/4 devices.
It's based on the patch submitted by Braun (many thanks!).

Right now it works on the F4, I will port it to the F3 and F0 in the following days/weeks.
So far I just added circular buffer support.

The code is here: https://github.com/mobyfab/ChibiOS/tree/dac
You can see the differences with the current trunk here: https://github.com/mobyfab/ChibiOS/compare/dac

The example for F4 discovery is here: https://github.com/mobyfab/ChibiOS-Exam ... DSP/main.c (video: http://www.youtube.com/watch?v=PqdnNBhFhbI)
I will make a simpler example as this one uses my DSP example using and LCD and so on.

[Tectu]

Good work! I'd really love to finally see the DAC driver inside the ChibiOS/RT mainline. Maybe the other platform maintainers should be contacted to create a port since they might not read this forum (and yes, I don't know if any other, currently supported, platforms do provide a DAC).


~ Tectu

[Giovanni]

Hi,

Thanks for the work, it is really needed.

I need to specify that this will have to go post-2.6.0 or directly in 3.0.x. I need to release 2.6.0 ASAP and I am doing just fixing right now.

Giovanni

[mobyfab]

Hi,

I got both channels working with their own DMA stream and timer (TIM6 & 7)

I will work on the F0/3 implementations in the following days.

The git repo has been updated.

[mobyfab]

I have updated the code with drivers and testhal demos for F0/30/37.

I had to add some code specific to the basic timers they use.

I will test them this evening on F0/F3 discovery boards, since they compile fine.

if someone has a F37x board and a scope, some testing would be helpful.

[mobyfab]

Good news, I have almost finished writing the driver

Tested and works fine on F0 F30 and F4! (after some fixes)
Untested on F37 but very likely to work.

Video: http://www.youtube.com/watch?v=JZrWxAi_U0s

[Giovanni]

Hi,

Would be possible to keep the API as close as possible to that unfinished I2S driver? basically they do the same thing. Probably there is no need for an explicit double buffered function. It works like the ADC on reverse.

For ChibiOS 3.0 I am thinking to give a "circular" capability to the SPI driver and make it some kind of common infrastructure for SPI/I2S/DAC (not sure about ADC) and similar.

Giovanni

[mobyfab]

Hi,

What I could do it use the same function names and define the DMA mode and buffers in the config structure like the I2S driver.

Code: Select all

void dacInit(void);
void dacObjectInit(DACDriver *dacp);
void dacStart(DACDriver *dacp, const DACConfig *config);
void dacStop(DACDriver *dacp);
void dacStartSend(DACDriver *dacp);
void dacStopSend(DACDriver *dacp);
void dacSend(DACDriver *dacp);

Does that sound good to you?

I am also moving the dac driver to the STM32 folder as it's pretty much the same for all STM32 devices.

[Giovanni]

That would be perfect. I would locate the files under ./STM32/DACv1 just in case it will change in some future STM32.

Giovanni

[mobyfab]

It's done.

I have added support and demos for F1 and L1 devices. (untested)

The coding style is probably not perfect but there should not be too many things to modify.