Strange idle current consumption

RE: Strange idle current consumption

Igor — Tue, 05 Nov 2019 12:52:16 GMT

Fixed.
It turned out to be related to SAADC with oversampling. Oversampling produces multiple measurements. CPU won't enter into sleep mode until all measurements are consumed. So, if this (accidentally) happens, current may be unusually high.

RE: Strange idle current consumption

Simonr — Tue, 12 Mar 2019 14:28:50 GMT

Hi Igor

It is hard to find out without knowing your code or custom chip. But always when having problems with custom boards can you try the same software on a development kit or similar, so we can find out if the problem is with the hardware or software. Also, if you are using the timer STOP task, there is errata on that particular task causing the nRF52840 to draw excess current. Can you check if this might be the reason for your current draw?

Best regards,

Simon

RE: Strange idle current consumption

Igor — Tue, 12 Mar 2019 14:02:24 GMT

It was a typo. 900 uA is correct value.

No of timer has 2 min interval (all are much shorter).

RE: Strange idle current consumption

Simonr — Tue, 12 Mar 2019 07:13:14 GMT

Hi Igor

As Turbo J says, you should be able to find components getting very warm during those two minutes with 900mA current draw. Do you have any 2 minute timers in your code which can explain why you have 2 minutes of high current draw and 2 minutes of low draw?

Best regards,

Simon

RE: Strange idle current consumption

Turbo J — Mon, 11 Mar 2019 19:36:36 GMT

With 900mA through an NRF5284 for 2 minutes, you would be looking at the smoking remains of a chip.

I recommend looking at other components in your circuit - it should get pretty warm...