battery needs recharging. Lipoly batteries are 'maxed out' at 4.2V and stick around 3.7V for much of the battery life,

then slowly sink down to 3.2V or so before the protection circuitry cuts it off. By measuring the voltage you can quickly

tell when you're heading below 3.7V

Since the ESP8266 does not have multiple ADC pins, we didn't want to 'sacrifice' one for Lipoly battery monitoring.

However we do have a tutorial that mentions how to do it, using two resistors. You cancheck out the wiring diagram

here (use the VBat pin to measure) and the code here.

ENable pin

If you'd like to turn off the 3.3V regulator, you can do that with the EN(able) pin. Simply tie this pin to Ground and it will

disable the 3V regulator. The BAT and USB pins will still be powered

© Adafruit Industries

https://learn.adafruit.com/adafruit-feather-huzzah-esp8266

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