Connecting a 7 Segment LED Display to ICL7107
Here is a diagram showing how to wire a single seven-segment LED display to the ICL7107. The same principle applies to the rest of the remaining LED displays, and below is a table showing the mapping between all the pins of the seven-segment display and the ICL7107 chip.
LED Display | ICL7107 | |||||
Segment | LED Pin No | Pin No | Pin Designation | |||
Display 4 | - | 10 | 20 | POL | ||
c | 4 | 19 | AB4 | |||
b | 6 | 19 | AB4 | |||
Display 3 | g | 10 | 22 | G3 | ||
f | 9 | 17 | F3 | |||
e | 1 | 18 | E3 | |||
d | 2 | 15 | D3 | |||
c | 4 | 24 | C3 | |||
b | 6 | 16 | B3 | |||
a | 7 | 23 | A3 | |||
Display 2 | g | 10 | 25 | G2 | ||
f | 9 | 13 | F2 | |||
e | 1 | 14 | E2 | |||
d | 2 | 9 | D2 | |||
c | 4 | 10 | C2 | |||
b | 6 | 11 | B2 | |||
a | 7 | 12 | A2 | |||
Display 1 | g | 10 | 7 | G1 | ||
f | 9 | 6 | F1 | |||
e | 1 | 8 | E1 | |||
d | 2 | 2 | D1 | |||
c | 4 | 3 | C1 | |||
b | 6 | 4 | B1 | |||
a | 7 | 5 | A1 |
Here is the complete wiring table that maps the pins on the LED display modules with the pins on the ICL7107 chip. Pin 8 and pin 3 on all the display modules join to Vcc, and the decimal point is pin 5 on all modules.