How about drilling a tiny hole in the led? John Ferrell 6241 Phillippi Rd Julian NC 27283 Phone: (336)685-9606 johnferrell@earthlink.net Dixie Competition Products NSRCA 479 AMA 4190 W8CCW "My Competition is Not My Enemy" ----- Original Message ----- From: "Picdude" To: Sent: Friday, August 22, 2003 12:54 PM Subject: [EE:] How can I destroy select LED segments? I'll probably get sent off to the looney-bin for this one, but it's worth a shot still... I'm working on a PIC circuit that will send its output to a few 7-seg LED's. The 7-seg displays are all part of one integrated multiplexed unit, but only one digit will need to have the DP (decimal-point) on, and it will always be on. However, I'm just one pin short, and I'd like to avoid adding more parts (by multiplexing, etc), so I thought of just running outputs to the 7 main segments, and hard-wiring the DP to be always on. But this means I need to destroy the DP on the other digits (which will always have the DP off). So if I selectively zap each of the OFF decimal points with say 12V, can I selectively destroy those dp's WITHOUT destroying any other display segments? Standard logic tells me I should be okay, but I fear that there's more to it. FWIW, I found another way to solve this problem (sending the column-select output of the digit with the ON DP to the DP input of the display, and using CA displays with NPN transistors). But I think that burning out unwanted segments can be very useful for other purposes, so the question still stands. Cheers, -Neil. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.