3 Digit Common Cathode 0.5″ – 7 Segment Display Module (Multiplexed)

This is a 3 Digit 7-segment display project that contains 3 x Common Cathode displays, current limiting resistors or each LED segment, 3 x PNP Transistor on each common cathode for multiplexing etc. The project works with 5V TTL signals but can be optimized for 3.3V operations by reducing the current limiting resistors' value.

Multiplexed Display Info

https://en.wikipedia.org/wiki/Multiplexed_display

• PIN 1 NC (VCC-NO USE)
• PIN 2 SEGMENT A
• PIN 3 SEGMENT B
• PIN 4 SEGMENT C
• PIN 5 SEMENT D
• PIN 6 SEGMENT E
• PIN 7 SEGMENT F
• PIN 8 SEGMENT G
• PIN 9 DP
• PIN 10 DISPLAY 1 CATHODE (BC847 BASE)
• PIN 11 DISPLAY 2 CATHODE (BC847 BASE)
• PIN 12 DISPLAY 3 CATHODE (BC847 BASE)
• PIN 13 GND
• PIN 14 NC

Arduino Code

Arduino code is provided to test the board. The user will be able to create a 0 to 5V DC Voltmeter using this code. Upload the code to Arduino Uno, apply 0 to 5V to Analog Pin A0 to Measure the voltage. Refer Arduino pin configuration vs display bellow:

• Digital Pin D12 = Display 1 Cathode
• Digital Pin D11 = Display 2 Cathode
• Digital Pin D10 = Display 3 Cathode
• Digital Pin D2 = Display Segment A
• Digital Pin D3 = Display Segment B
• Digital Pin D4 = Display Segment C
• Digital Pin D5 = Display Segment D
• Digital Pin D6 = Display Segment E
• Digital Pin D7 = Display Segment F
• Digital Pin D8 = Display Segment G
• Digital Pin D9 = Display Segment DP
• Analog Pin Input = A0 5V Meter