Debugging Power using on nRF52

RE: Debugging Power using on nRF52

Gordon — Mon, 11 Jul 2016 11:58:18 GMT

Ahh, thanks. Unfortunately I'm not using Keil - but even so it looks like it's a matter of checking each individual peripheral in turn :(

RE: Debugging Power using on nRF52

Øyvind Karlsen — Mon, 11 Jul 2016 11:52:52 GMT

Hi,

Follow this question to enable debug mode. In a Keil debug session you can press

Peripherals -> System Viewer -> [YOUR DESIRED PERIPHERAL]

Set a breakpoint at sd_app_evt_wait() and observe the register values in the right hand bar. You can also use a multimeter to monitor current (a bit rough, won't work for high speed changes, but sometimes enough to estimate).

RE: Debugging Power using on nRF52

Gordon — Mon, 11 Jul 2016 11:47:54 GMT

Ok, thanks! So is there a way to debug this? For instance suppose I forgot to stop TIMER1 but I didn't know that - is there a register that I could read the value of that would tell me which devices were causing the HF clock to stay on - or do I have to check every single device individually?

RE: Debugging Power using on nRF52

Øyvind Karlsen — Mon, 11 Jul 2016 11:40:33 GMT

Unfortunately no, as it is differs a lot depending on application. Essentially you just want to release resources when you are done using them. The application time tutorial explains how to do this for the applciation timer. For the TIMER you will want to clear the timer and stop it by calling, make sure to also clear pending interrupts

NRF_TIMER1->TASKS_CLEAR = 1;
NRF_TIMER1->TASKS_STOP = 1;

RE: Debugging Power using on nRF52

Gordon — Mon, 11 Jul 2016 10:49:12 GMT

Ok - thanks - do any of the examples in Nordic's SDK do this, so I can see how it is done? All examples I've found so far just use sd_app_evt_wait - so I assume that all of those will draw so much power they are not usable on a battery?

RE: Debugging Power using on nRF52

Øyvind Karlsen — Mon, 11 Jul 2016 10:31:51 GMT

Yes, this is right. You have to manually turn it off before calling sd_app_evt_wait if you do not need it.

RE: Debugging Power using on nRF52

Gordon — Mon, 11 Jul 2016 09:52:21 GMT

Thanks! But how do I do that? I was under the impression that HFCLK was turned off automatically by the hardware and/or sd_app_evt_wait if it was possible to do it? I thought that if it was on, it was left on because some hardware was using it?

RE: Debugging Power using on nRF52

Øyvind Karlsen — Mon, 11 Jul 2016 08:15:17 GMT

Hi,

Likely you are running the HFCLK which consumes current on this order, try disabling it before you go to sleep.

Best regards,

Øyvind