Similarly, the segments for each digit are connected together as well, so one pin on the micro controls the same segment on each of the digits. The microcontroller in question is the AVR ATMega48.

We here at Hack A Day love LED’s, and all things LED related, but one of the biggest problems with LED’s are the small size. We want bigger and brighter, matrices the size of our TV, se… ...

For testing purpose only one 330 Ohm resistor (R2) is added between ground rail (0V) and the common cathode pins (3 & 8). It is better to directly connect pins 3 & 8 of the display to ground rail.

The finished circuit can display numbers ranging from 0 through 1023, in connection with a 10K preset pot attached to the analog input A0 of the Arduino board. This 4 -digit 7-segment display section ...