Feather 32u4 Adalogger is built in with USB and battery charging. Feather 32u4's heart is at ATmega32u4 clocked at 8 MHz and at 3.3V logic, a chip setup with 32K of flash and 2K of RAM. It has 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. The Feather will automatically switch over to USB power when its available.
- Product dimension : 2.0" x 0.9" x 0.28" (51mm x 23mm x 8mm).
- Weight : 5.1 grams.
- ATmega32u4 @ 8MHz with 3.3V logic/power.
- RAM : 32KB.
- No EEPROM.
- 3.3V regulator with 500mA peak current output.
- USB native support, comes with USB bootloader and serial port debugging.
- GPIO pins : 20.
- Hardware Serial, hardware I2C, hardware SPI support.
- PWM pins : 8.
- Analog inputs : 10.
- Built in 100mA lipoly charger with charging status indicator LED.
- Power/enable pin.