CH552TinyPad 6 key macropad with USB microcontroller CH552T bill of materials R1: 330 R2: 10k R3, R4: 5.1k C1, C2: 0.1uF U1: CH552T J1: PinHeader 2x10 J2: USB-C receptacle U1: CH552T SW1~SW6: CherryMX compatible keyswitch SW7: SMD tactile switch