The project presented here is an open source 2-digit 7 segment Arduino compatible display board. It can used in many applications that require 2-digit display and switches inputs. Possible application of this board is a 2-digit counter, 2-digit countdown timer, token display, score board etc. 2 x 7 segment 0.56-inch Common cathode displays are used in multiplexing mode. Refer to the connection table to check connections between display segments and Atmega328 chip. A led connected to A4 pin of IC is used as indicator LED. All 3 switches have pull-up resistors of 10Kohms, 220E ohms series resistors used between I/O pin of Atmega328 chip and display segments.
Arduino Compatible 2-digit 7-segment Display Board for Timer/Counter – [Link]