Multiplexing for an LED display?
**broken link removed**
The way it works is, there is a common connection for each segment in the display, each segment in 1 digit is referred to as a,b,c,d,e,f,g and dp for the decimal. (driven by pins D0-D7 in the schematic).
There is an enable signal (at the top of the LED displays) for each digit. By enabling each digit one at a time, and changing the 'D' pins at the same time, you can display a different number on each display. So if you wanted to display 123456 on the display, you would enable LED1 and set the 'D' pins to display a 1, then disable LED1 and enable LED2 and set the D pins to display a 2.
So each digit is only turned on for 1/6th of the time. By switching between the LEDs fast enough you cant even tell that they are being turned on and off. (about 20-30 times a second for the human eye). Also, the LEDs should be driven with alittle more current than the normal rating, since they will only be turned on 1/6th of the time, they will be dimmer than normal.
Hope this helps...