brand new puck.js v2 – already bricked?

[espruino-discuss]

Posted at 2020-08-24 by user117186

Hi,

i just got my new puckjs v2. Everything was working when i got it.

Here is how i apparently bricked it:

1. flashed https://www.espruino.com/binaries/espruino_2v06_puckjs.zip (even tho it already had that version. realized that later)
2. the next day: bluetooth connection would fail with the puck blinking red
3. tried to hard reset it, but I'm always only getting red blinking leds

did i already brick it – anything else i can try?

• i measured the battery, its 2.8V
• can not find the puck on bluetooth anymore
• it's only blinking red sometimes. and I can't get it to reproduce

edit: previously could not get any led to light up. it now blinks red – content edited to reflect that

[espruino-discuss]

Posted at 2020-08-24 by user117186

i feel kinda stupid. the battery simply was empty.

is the "flashing red to indicate low battery" a feature? because i did not see it documented anywhere

[gfwilliams]

Posted at 2020-08-24 by @gfwilliams

As you figured, at 2.8v the CR2032 batteries are basically only 10% charged.

is the "flashing red to indicate low battery" a feature?

It's not an intentional feature, but it does happen on the v2 for certain charge levels.

Basically at boot the accelerometer draws a bunch of power a fraction of a second after startup, so while Puck.js boots and flashes the red LED, the accelerometer pulls the battery voltage too low and causes a reboot loop.