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 progam 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, Adafruit added a connector for any of their 3.7V Lithium polymer batteries and built in battery charging. 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 its available.
We took a certified module with an onboard antenna, and plenty of pins, and soldered it onto our designed breakout PCBs. We added in:
- Reset button
- User button that can also put the chip into bootloading mode,
- Red LED you can blink
- Level shifting on the UART and reset pin
- 3.3V out, 500mA regulator (you’ll want to assume the ESP8266 can draw up to 250mA so budget accordingly)
- Two diode-protected power inputs (one for a USB cable, another for a battery)
The module itself is FCC certified and contains the ESP8266 chip with 64 KiB of instruction RAM, 96 KiB of data RAM, and 4 MB of QIO FLASH (32 Megabits)