Introduction: In this circuit, we will show how to display numerals on a 4-digit 7-segment display just by directing using any Arduino microcontroller with no other external chips such as LED display drivers.
Each segment in the display module is multiplexed, meaning it shares the same anode connection points. And each of the four digits in the module have their own common cathode connection point. This allows each digit to be turned on or off independently. Also, this multiplexing technique turns the massive amount of microcontroller pins necessary to control a display into just eleven or twelve (in place of thirty-two)
Learn More about 4-digit-7 segment display
- Arduino Uno
- 4-digit 7-segment LED display
- 4 1KΩ resistors
- 4 2N3904 NPN transistors or any other NPN transistor
- Potentiometer/Variable Resistor