Power Pins

GND - this is the common ground for all power and logic

BAT - this is the positive voltage to/from the JST jack for the optional Lipoly battery

USB - this is the positive voltage to/from the micro USB jack if connected

EN - this is the 3.3V regulator's enable pin. It's pulled up, so connect to ground to disable the 3.3V regulator

3V - this is the output from the 3.3V regulator, it can supply 500mA peak (try to keep your current draw under

250mA so you have plenty for the ESP8266's power requirements!)

Logic pins

This is the general purpose I/O pin set for the microcontroller. All logic is 3.3V

Serial pins

The ESP8266 runs on 3.3V power and logic, and unless otherwise specified, GPIO pins are not 5V safe! The

analog pin is also 1.0V max!

© Adafruit Industries

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

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