Would like some help with IOCards display...

[Guest christianholmes]

Hi,So I bought the Displays II card, got it all put together, and have a bunch of LEDs.Can somebody explain how how to wire 2 or more 7-segment displays to it?I'm totally confused- I bought the 5 digit PCB board, and soldered 5 7-segment displays to it, but there are only 13 pins- I just don't understand how 5 displays, with 8 pins (40 pins) can be controlled by 13 pins on the PCB.Has anyone tackled this, and care to share and explanation/pictures?Thanks very much.

[Guest MikePowell]

Christian,Groups of 7-segment displays are normally multiplexed to reduce the number of I/O pins needed to drive them. Each display has a common pin that connects to one end of all the LEDs. The other ends each have their own pin. This allows all the displays to be connected in parallel. All the display pins EXCEPT for the common pin are wired in parallel to the drivers. The common pin is used to activate the displays one at a time. During multiplexed operation the data for the first digit is placed on the paralleled connection as the common pin of the first display is used to activate it for a brief instant. Then the data for the next digit is placed on the parallel connection and that display is activated for a brief instant. And so on...I don't know the details of the system you are using, but perhaps this will help.Mikewww.mikesflightdeck.com

[Guest Ferdie]

The Display Card multiplexed connect with digits exactly like Mike explain to you.This is a example of connections :http://www.opencockpits.com/modules.php?na...rmine&cat=10728

[Guest christianholmes]

ah ha....I didn't realize that is how they worked...That makes more sense.Now, Can anybody tell me where to buy common cathode 7-seg displays that fit the OC PCBs? They have yellow ones on their site- I want red.

[Guest GeorgeDorkofikis]

At any good electronics store.They red ones you can use instead are the KnightBright SC36-11SRWA.George DorkofikisAthens, Hellashttp://online.vatsimindicators.net/811520/1704.png