multiple timers not working on nrf52832 Dev Kit

RE: multiple timers not working on nrf52832 Dev Kit

Ed — Thu, 12 Oct 2017 14:51:46 GMT

perfect -thank you for following up on this question

RE: multiple timers not working on nrf52832 Dev Kit

Sigurd — Wed, 11 Oct 2017 10:53:30 GMT

It have to do with interrupt latency in the ARM Cortex-M4 core. It takes time to both enter and exit the interrupt. It should be documented by ARM. See this link.

RE: multiple timers not working on nrf52832 Dev Kit

Ed — Wed, 04 Oct 2017 14:55:17 GMT

Thank you for clarifying this Sigurd. You said 1us is too fast, but what are the limits? Where are the limitations of the interrupts documented? Furthermore, this seems like a timer peripheral limitation so it probably should be documented somewhere.

RE: multiple timers not working on nrf52832 Dev Kit

Sigurd — Wed, 04 Oct 2017 13:54:42 GMT

Hi,

You need to use PPI for this. 1us is too fast for regular interrupts. You can find a tutorial that shows how to configure a Timer to toggle a GPIO pin, in software and by using PPI and GPIOTE to bypass the CPU at this GitHub page.

You should also consider using the PWM for this, since the nRF52832 have dedicated PWM hardware. You can find a simple PWM example in this post.