My experience with installing speed monitor equipment on automobiles has been mixed. I have found is that noise can be introduced into the automobile speed sensor devices causing problems from nuisances to true safety concerns. Perhaps a better alternative, both from safety and cost, might be to monitor when the vehicle is in gear and then cause the doors to lock. You would want to assure that you only pulse the locks so a passenger can unlock the door to exit. If you still want to monitor the vehicle speed signal you may want to use the LM1815. In several instances we had to use an opto isolator circuit using a National LM1815 to sense the speed signal and then drive the opto isolator. Link to Data sheet is provided: http://www.national.com/pf/LM/LM1815.html Hope this helps. ----- Original Message ----- From: "Hulatt, Jon" To: Sent: Tuesday, September 23, 2003 12:54 PM Subject: Re: [EE] (automotive) frequency trigger > hehe, no, really 10mph. I want to lock the doors when i get to 10mph, and > then unlock them when the engine turns off. Seems to be a good second pic > project, and also a simple anti-hijack tool. which is a risk in that car. > > -----Original Message----- > From: Eric Schleicher > To: PICLIST@MITVMA.MIT.EDU > Sent: 23/09/2003 13:15 > Subject: Re: [EE] (automotive) frequency trigger > > So you rally meant 100 MPH didn't you... > > > > What type of vehicle is it? > > > > A Nissan Skyline GT-R (1997 model) > > > > -- > 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 -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu