Tag Archives: microcontroller
Interfacing Multiplexed Display
To solve the problems of the static display approach, multiplexed display method is used. Here 4 seven segment displays connected using multiplexed method. Here common anode seven segment LEDs are used. Anodes are connected to +5V through transistors. Cathodes of all seven segments are connected in parallel and then to the output of 7447 IC through resistors. The PNP transistors connected in series with the common anode of each digit act as an ON and OFF switch for that digit. Here is how the multiplex process works.
In multiplexed display, the segment current is kept in between 40mA to 60 mA. So that they will appear as they would if not multiplexed. Even with this increased segment current, multiplexing gives a large saving in power and hardware components.
