The two wire bi-colour LED's usually require the supply voltage polarity to be reversed to change the colour. To control them from a PIC would require an H-pack (or bridge) configuration. One wire of the LED's to connect to a voltage divider giving half supply voltage and the other wire to a pipolar PIC I/O pin so that when the PIC output goes high it gives polarity for red and when low it gives polarity for green. You still have to work out how to control the LED's when you want them both off. An easier method might be to regonfigure your design so that tou can use 3 wire bi-colour led"s Regards Harry ----- Original Message ----- From: "Anthony Van Herrewege" To: Sent: Friday, June 25, 2004 8:39 AM Subject: [PIC:] Controlling 8 bi-color LED > Hi, > > I'm in the process of drawing up the schematics of my next project, a preamp. I'd like to be able to see the selected input on the front panel and decided to use Multimec switches (http://www.mec.dk/billeder/8_619.jpg). > > Because the preamp will have a tape loop output, I need to be able to see that as well on the front panel. I think bi-color leds (the ones with 2 pins, not those with 3, since they won't fit the switches) are the best for that. > > The problem is that I can't figure out how to connect those 8 bi-color leds to a shift register. Is it possible to connect 8 bi-color leds to an 8-bit shift register and control all of them? I need to be able to turn them all on independently, but there never won't be more than 1 green & 1 red lighted (in case I use red/green bi-color ones of course). Is there any kind of matrix-style connection possible for this or do I have to resort to a 16-bit shift register? Note the fact that I need to light 1 green & 1 red led at the same time, so usual matrix arangements won't work. > > Regards, Anthony Van Herrewege > > > Website: http://members.lycos.nl/anthonyvh > > > --------------------------------- > Do you Yahoo!? > Yahoo! Mail - 50x more storage than other providers! > > -- > http://www.piclist.com hint: To leave the PICList > mailto:piclist-unsubscribe-request@mitvma.mit.edu > > -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu