Just a quick brain dump of potential ideas: Maybe you can use different frequencies for each cable or use pulsed width modulation. The 16F877 might be a starting point, you may find a derivative of that model to create what you need. You could send a square wave out of the pic at different freqs to identify each cable or you could simply attach every wire to the pic at one end and a pic on the other end and write a program that will step thru all of the cables by simply using a dc voltage to match up each line using some type of algorithm and an lcd display. You could have one pic put a +5 on one wire, while the other pic scans all of the wires for a high ( may need 2.2K ohm pull down resistors to gnd for each wire to reduce noise). Once the high is detected then a match can be detected and the pic will advance to the next wire. Once a match is detected, you can repeat the process. But how do you notify the other Pic to move to the next cable? If you can run a serial cable between the two pics that would help coordinate the pics, otherwise, you could have both pics tying one line high while they are both scanning until a pair is located and then that pair can be used as the serial or clock signal to notify the other pic when a cable has been identified and when to move on to the next cable. If you use serial, you could have one pic tell the other pic the wire id and display the info on an LCD. Sounds like a fun project. -----Original Message----- From: George Shaw [mailto:george.shaw@UKF.NET] Sent: Monday, June 23, 2003 10:38 AM To: PICLIST@MITVMA.MIT.EDU Subject: [PIC]: Cable Tagger Project Hi all. Only just joined this group and hope to have fun as an active member. I start off with a question/request. I wish to build a device that will send an ID down a cable (twisted pair) and be picked up at the far end in order that the cable can be identified. Now I already use a tone and amplifier which will send a audio frequency tone down a wire and be picked up at the far end, using a commercial "Tone/Amp" set from Progressive. What I what is to be able to attach a series of "tones" or voice ID's to one end of say a 30 pair telecoms cable and read off which cable is which at the far side without having to physically switch the device from one pair to the next, ID'ing say 10-20 pairs at a time. There is a commercial unit that does what I want called the Voice IDer from Tempo at http://www.tempo.textron.com/products/prod_voicetaggers.html and http://www.tempo.textron.com/archive/ds_voicetaggers.pdf I want to build this type of device using a PIC ??? although I am totally new to PICs and their capabilities. OK now the question. Can anyone help out with a design/circuit or any ideas as to how it could be designed built programmed? -- George Shaw MI3GTO " Any Sufficiently Advanced Technology is Indistinguishable from Magic" ---Arthur C. Clarke Mobile: +44 (0) 7740 361 163 Email: george.shaw@ukf.net Fax & Voicemail: +44 (0) 871 242 9183 --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.491 / Virus Database: 290 - Release Date: 18/06/03 -- 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.