Quantity   Component name
1 × atmega168-20pu Microprocessors, Microcontrollers, DSPs / ARM, RISC-Based Microcontrollers, see http://www.atmel.com/Images/Atmel-2545-8-bit-AVR-Microcontroller-ATmega48-88-168_Datasheet.pdf
1 × a4988d stpper motor driver, up to 1/16 step, see https://www.pololu.com/product/1182
1 × m74hc5981