Can't put Adafruit NRF52 Feather board into Low Power

RE: Can't put Adafruit NRF52 Feather board into Low Power

Mason — Thu, 04 Jan 2018 17:55:39 GMT

Got an official response from Adafruit, and it turns out that my excess power draw was due to the CP2104 USB to Serial chip. Removing the chip brought the power draw down into the microamps to a level that was sustainable for my purposes.

Apparently they will be releasing a new board using a different low power component. forums.adafruit.com/viewtopic.php

RE: Can't put Adafruit NRF52 Feather board into Low Power

Stian Røed Hafskjold — Thu, 04 Jan 2018 11:17:31 GMT

I flashed the 6mA and 14mA hex-files to a clean nRF52832 test board, and the results were 130µA and 7mA respectively. The 130µA seems to be the result of the RTC timer triggering every 1ms, and the idle current between the RTC peak looks fine (~1µA). The 7mA result is most likely caused by the CPU running and never reaching the WFE loop.

So my conclution is that there must be something else on that Adafruit board that consumes the additional ~6mA. Are you sure the USB brigde is in idle mode?

RE: Can't put Adafruit NRF52 Feather board into Low Power

Mason — Wed, 03 Jan 2018 16:16:43 GMT

Edited the main post to include them, thank you very much!

RE: Can't put Adafruit NRF52 Feather board into Low Power

Stian Røed Hafskjold — Wed, 03 Jan 2018 10:54:20 GMT

I have to order one of these boards first. Meanwhile, can you please post the 14mA hex file and the 6mA hex file? Then I can run them here and see what is going on.