It contains everything needed to support the microcontroller simply connect it to a computer with a USB cable or power it with a AC-to-DC adapter or battery to get started. It has 14 digital input/output pins (of which 6 can be used as PWM outputs), 6 analog inputs, a 16 MHz quartz crystal, a USB connection, a power jack, 2 ICSP headers and a reset button. Keyestudio Uno R3 is a microcontroller board based on the ATmega328 (datasheet), fully compatible with ARDUINO UNO REV3.
