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Topic: Turning oFf LED in MKR 1400 (Read 549 times) previous topic - next topic

amirf

Apr 07, 2019, 03:17 pm Last Edit: Apr 08, 2019, 03:04 am by amirf
Is there anyway to turn off LED in MKR1400 after putting it into deepSleep().
It is powered from battery through Vin pin and the green power is on always. Any insight into power usage by this board and how to make the battery last for a few months would be appreciated.

pert

The only way is to remove the LED from the board. Luckily, the location makes this fairly easy to do. The tricky part is to avoid disturbing the nearby components if possible. Luckily, there is a good amount of space around the LED so it should be possible with a bit of careful work with your soldering iron.

amirf

I keep getting an orange LED light blinking occasionally when the battery is connected.

pert

The charge controller chip on the MKR GSM 1400 is the BQ24195L. The "CHRG" LED is connected to its "STAT" pin. The behavior of the STAT pin is described in table 8.3.4.1 of the datasheet:
http://www.ti.com/lit/ds/symlink/bq24195.pdf

CHARGING STATE                                | STAT
===============================================================
Charging in progress (including recharge)     | LOW
Charging complete                             | HIGH
Sleep mode, charge disable                    | HIGH
Charge suspend (Input over-voltage, TS fault, | Blinking at 1Hz
timer fault, input or system over-voltage)


So there are a number of things that can cause blinking. There is a charge timer that automatically stop the charge after a specific amount of time if the battery is still not detected to be fully charged. The idea is to avoid creating a dangerous situation by overcharging the battery if something has gone wrong. If you have a battery connected that has a capacity that causes it to not be fully charged after the safety timer duration, the timer would time out and the LED would blink. You should be able to identify if the blink is caused by the safety timer by timing how long it takes before the blink occurs.

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