At the Feather HUZZAH’s heart is an ESP8266 WiFi microcontroller clocked at 80 MHz and at 3.3V logic. This microcontroller contains a Tensilica chip core as well as a full WiFi stack. You can program the microcontroller using the Arduino IDE for an easy-to-run Internet of Things core. We wired up a USB-Serial chip that an upload code at a blistering 921600 baud for fast development time. It also has auto-reset so no noodling with pins and reset button pressings.

To make it easy to use for portable projects, they added a connector for any of the 3.7V Lithium polymer batteries we stock and included a built in battery charging circuit. You don’t need a battery, it will run just fine straight from the micro USB connector. But, if you do have a battery, you can take it on the go, then plug in the USB to recharge. The Feather will automatically switch over to USB power when it is plugged in using a micro USB cable available.

As of January 2021 this is now Revision G, and includes a slightly improved power selection circuit. It will no longer back-power USB if a battery is plugged in.