Boron's LTE Charge State LED

boron
Tags: #<Tag:0x00007fe2203c0f50>

#1

Not sure if this is normal or not but periodically the Boron’s LTE charge state LED will go off and on for a few seconds without any battery connected. I only have a power supply connected. Also, none of my code checks for voltage or battery presents. Device OS:1.3.0-rc.1

Is this normal? Why is it doing it?


#2

From Boron datasheet:

You can stop this behavior by either plugging in the LiPo battery or by disabling charging using firmware command: PMIC().disableCharging(); .


#3

Perfect. Thanks!


#4

This is because the charger thinks that there is a battery connected. It attempts to charge and finishes charging quickly. (Led turn on and almost immediately turn off) After a short amount of time that node will then fall below the charging threshold and the charger starts all over again.

In some cases, that node gets discharged very quickly. This causes the LED to flash constantly. Sometimes it will flicker a few times. Sometimes it won’t do it at all!

As far as I can tell it’s a board to board variation.

For the boron it’s easy to fix as @dreamER suggested. For the other boards, you don’t get that luxury!