nRF52832: Determine current position in sequence PWM with DMA

RE: nRF52832: Determine current position in sequence PWM with DMA

David — Tue, 26 Jun 2018 14:25:46 GMT

Thank you for the suggestion.

I was thinking about doing the counting in an IRQ in software, but using one of the Timers to count the steps is a great idea. I could also use a PPI to connect EVENTS_LOOPSDONE or EVENTS_SEQEND to TASKS_CLEAR.

RE: nRF52832: Determine current position in sequence PWM with DMA

CheMax — Tue, 26 Jun 2018 14:18:38 GMT

May be use a timer as counter?

If connect EVENTS_PWMPERIODEN to timer COUNT task with PPI. timer in comparison mode.

The new value in the PWM generator is delivered after the completion of the previous period (if delays are not included). Means knowing how many periods have passed, you can understand on which line of the table we are.

Theoretically it can work out, but this must be checked.

RE: nRF52832: Determine current position in sequence PWM with DMA

Håkon Alseth — Tue, 26 Jun 2018 14:02:18 GMT

Hi,

[quote user=""]Let's say that while the PWM is outputting COMP0[3], my application wants to know the current state of the PWM. Is there a way to read what values are loaded into the DMA or where the DMA is currently pointed?[/quote]

Unfortunately, there is no way to see where you are in an ongoing PWM sequence.

Best regards,

Håkon