The ATTINY861A-MU is a 8-bit microcontroller from Microchip and belongs to the AVR RISC-based family. It has 8K Bytes of In-System Programmable (ISP) Flash, 512 Bytes of SRAM, 1K Bytes of EEPROM and up to 32 I/O lines. It is also equipped with two 8-bit and one 16-bit Timer/Counters, 9-channel 10-bit ADC and 4 USARTs. Additionally, it is equipped with a JTAG port, watchdog timer and UPDI (Universal Programming and Debug Interface), Internal and External Interrupts, I2C and SPI controllers and POR, PWM, WDT and BOD power management features. The operating voltage range is 2.7V to 5.5V.