7 Segment Display

How to tell if you have a common anode or a common cathode 7 segment display?

by Kalpasjack
January 02, 2020

As far as I know all 7 segment displays are able to work both in a common anode and a common cathode mode.

With a 7 segment display you have 8 control pins (1 for each segment + 1 for the dot) and 2 power pins (Vcc and GND). Usually these are pins 3 and 8 (so the middle bottom and middle top ones), not necessarily in that order.

You don't connect both of these power pins, only one based on if you want common anode or common cathode. With common anode you're applying a common voltage to Vcc (usually +5 volts in series to a 510 ohm - 1 kiloohm resistor), while the pins of the segments you want to light up are connected to the ground.

With common cathode mode you connect the GND pin to ground and bring positive voltage to the pins of the segments you want to light up .

Hope this helps.

by miminyte
January 03, 2020

Yes it helps and I Thank you very much.

by Kalpasjack
January 03, 2020
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