Thanks, Ashley, this is a really cool trick! I suppose you could light more than one LED with various combinations of 1 and 0. I am supposed to be implementing a light bar, sort of like a progress baar on a download, so I will have to count up. This may not work so well in this case, because I think adjacent LEDs cannot be lit in the same color! You suggested a little port expander, another cheap chip that I have used is an 8-bit serial load parallel out shift register, 74HC164. These can be bought for $US0.15 in quantity, I think. I need to check the datasheet and see how many LED's thay can handle. I guess the problem is to figure out which of these alternatives is the cheapest. --Lawrence ----- Original Message ----- From: "Ashley Roll" To: Sent: Friday, February 01, 2002 6:09 PM Subject: Re: [PIC]: Driving a dual LED > Hi Lawrence, > > Not sure exactly what your requirements are but if you can multiplex and > have 9 pins you can easily drive the 8 bi-colour LEDs. This is a trick I've > done before and it only requires a few normal current limiting resistors. > I've done this trick with two single colour LEDs per leg (wired like a > bi-colour), so I'm sure this will work. -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listserv@mitvma.mit.edu with SET PICList DIGEST in the body