SAMR21G18 MCU: Cortex M0+ CPU up to 48MHz, 256kB flash, 32kB RAM, IEEE 802.15.4 radio, capacitive touch.
4-Mbit DataFlash for data and firmware image storage. Up to 64Mbit pin compatible options available.
Dual row 100mil extension header.
Through hole or SMD mounting (no USB for SMD).
15 configurable GPIO/peripheral pins.
Standard 10-pin Cortex Debug connector.
Green user LED.
Reverse power protection.
Supply voltage range : 1.8V - 3.3V. With LDO: up to 5.5V.
Input voltage measurement.
Capacitive touch pins with as much clearance as possible to minimize ground loading.