ChibiOS Free Embedded RTOS

I found the problem. It turns out that the ARPE flag is only set for TIMs used for PWM, so (as I suspected) the problem likely was that it was updating the AAR register with a value that was less than where the current counter was at, so it had to wrap the counter before it updated again.

I fixed ...

After a bit more research and thinking about this, I'm not sure I fully understand your comment: "The interval is changed in next cycle, not the current one".

My understanding is that the GPT is just being used as a clock for the DAC DMA, so it knows nothing about the DMA buffer. So, the GPT "cycle ...

I could also have two data buffers (one for each frequency) and do one-shot DMAs for just the duration that I need for outputting a single bit. The only problems are that I have to track the phase so I don't have phase discontinuity, and re-starting the DMA would have to be low enough latency ...

By "cycle" I assume you mean that when it starts at the beginning of the buffer again? If that's true, then I don't think it will work for what I'm trying to do. I need it to take effect sometime around when the next sample would go out.

In any case, I don't think that's the problem. The "flat ...

I'm using DMA to a DAC on an F07 MCU, which is working well, at least for a constant update interval. I want to use it for generating an AFSK signal, and I was hoping that I could change the frequency by simple updating the interval, but that doesn't seem to be working correctly.

In order to ...

Just to close it out. Changing to TIM6 works like a champ.

Thanks!

I'm very interested in what you come up with here. I've been writing EX drivers for a couple of RF transceiver chips lately and those things have a *ton* of configuration parameters. Currently I'm exposing more-or-less all of them in the Config struct and making sure to put together a sensible ...

I know I'm replying to an old topic, but this is one that interests me.

I don't see why RF Transceiver would would be too different to generalize in a standard interface. I would take a look at the RadioHead library , which supports many different radio modules. It might not be the ideal interface ...

I think I see the problem now. There was no definition of STM32_GPT_USE_TIM6 in the mcuconf.h file. This is probably because it doesn't exist on all F0 devices. In any case, adding that, setting it to TRUE and changing to TIM6 at least compiles. I expect it will work now, but I can't test it for a ...

I'm sure I tried that because the example was using TIM6, but maybe I switched TIMs for the wrong reason. I'll try changing it back this evening and see if that fixes it.