A continuity tester is a simple device that tests the continuity of a circuit. To use it to test a resistor, follow these steps: Step 1: Turn off all power sources to the circuit. Step 2: Connect one ...

ATmega328p micro-controller as per schematic or alternatively a Arduino uno/nano module. Resistors: 20 ohms , 220 ohms, 660 ohms, 10K , 500ohms X 7, 1K X 4 Transistors 4 X 2N2222 NPN One 4 digit seven ...