At the Feather HUZZAH’s heart is an ESP-12 module. You can progam the microcontroller using the Arduino IDE for an easy-to-run Internet of Things core or using the NodeMCU firmware. Fast code download with 921600 and auto-reset before download are available.
To make it easy to use for portable projects, a connector for a 3.7V Lithium polymer batteries and built in battery charging are added. No battery is needed when powering over the micro USB connector. But, if you do have a battery, you can take it on the go as wearable for example, then plug in the USB to recharge.