This project will help you to easily develop an Arduino compatible project that requires 3 x 7-Segment 0.5″ displays. These are common cathode displays that use multiplexed configuration, BC847 transistor drives 3 x common cathodes, all display segments are connected to the microcontroller using current limiting resistors. The circuit operates with 5V DC, Connector CN1 is provided for bootloader and Arduino firmware upload. Upload Arduino code to test the board. The user will be able to create a 5.00V Voltage Meter. Use analog pin A0 for voltage input, Connector U2.
Arduino 3-Digit 0.5″ Common Cathode 7 Segment Display Module – [Link]