Quantity   Component name
1 × STC15W201S 8051 Microcontroller
2 × 74HCT595 Logic ICs / Flip-Flops, Latches, Registers
4 × ULN2001D Discrete Semiconductors / Transistor Arrays
1 × AMS1117-5.0 Voltage Regulator
12 × G2R-2-12VDC Switches and Relays / Electromechanical Relays