One of many in Adafruit’s new line of tiny microcontrollers, the ATmega Feather Basic Proto is designed to make protoyping easier. The small prototyping area is perfect for adding a sensor or button.
The onboard ATmega32u4 clocks at 8 MHz with 3.3V logic. It features 32K of flash and 2K of RAM, with built in USB. With a USB-to-Serial program & debugging capability built-in, there’s no need for an FTDI-like chip. It’s also well supported in the Arduino IDE and “can run just about every sensor/library out there,” according to Adafruit,
“To make it easy to use for portable projects, we added a connector for any of our 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.” You can even use an analog pin to monitor the battery voltage so you’ll know when it needs a charge.
The ATmega Feather Basic Proto is available online for $19.95. It comes fully assembled.