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Grand Central in standby sleep mode
Moderators: adafruit_support_bill, adafruit

Please be positive and constructive with your questions and comments.

Grand Central in standby sleep mode

by oferzv on Tue Mar 03, 2020 2:34 pm

HI all,

I am starting to work with the grand central and having problems getting to micro amp current levels in standby sleep mode.

When i execute the code below i get a current consumption of 7-9 mA How can I achieve better results ?

Code: Select all | TOGGLE FULL SIZE
USBDevice.detach();
USBDevice.end();
USBDevice.standby();

PM->SLEEPCFG.bit.SLEEPMODE = 0x4;
while (PM->SLEEPCFG.bit.SLEEPMODE != 0x4);

__DSB();
__WFI();



Thanks for the help

oferzv
 
Posts: 1
Joined: Thu Dec 21, 2017 9:24 am

Re: Grand Central in standby sleep mode

by adafruit_support_mike on Mon Mar 16, 2020 3:33 am

You'd have to remove a lot of chips from the board.

Low-power design is a specialty field, and that wasn't a design priority for the Grand Central. The NeoPixel draws about 1mA on its own, the circuit that controls the 5V regulator draws some current, and so on.

It's easier to use an external low-power timer like the TPL5110:

https://www.adafruit.com/product/3435

It uses less than 100nA if you cut the jumper to the power LED on the back, and about 20uA if you don't.

adafruit_support_mike
 
Posts: 61442
Joined: Thu Feb 11, 2010 2:51 pm

Please be positive and constructive with your questions and comments.