lock beep.... 09 GT

Bikerscum · Post by **Bikerscum** » Fri Jul 04, 2008 6:43 am

I find myself missing the beep. Having to look at the car is a bit of a pain. Wife's at work, I'm kinda house bound today, (bored) so I got to thinking about how to remedy the problem. There's, of course, the excellent solution offered here. But I'm a tinkerer This got me to thinking... "The two wires of importance that I used are White/Black, which is ground, and Yellow/Black, which is used for the lock/unlock flash signals from the MFAM (Multi Function Alarm Module) and the hazard blinker button.The Ye/Bk wire is normally at 12v. The hazard switch connects it to ground continuously when pressed, and the flasher relay does the blinking by itself.However, the MFAM pulses the wire to ground once for lock...." If there's an EE in the house, please keep me from myself! I know just enough about electronics to keep from electrocuting myself with 12 volts. But, I'm thinking a 555 timer IC wired as a one shot switch with the trigger line AC coupled to ground. Sounds a WHOLE lot more complicated than it is.... do a Google on 555 one shot & you'll master it in 5 minutes. The 555 wired as such triggers on a negative going pulse, & has an output time set by a single resistor. No matter how long the input, the output is always the same. Hold the input for a year.... it'll still only beep once. Radio Shack has the chip for $1.69. The thing I can't get past, is that the horn will beep once when the hazard button is pressed. Maybe not such a bad thing.... maybe even a good thing, but I'd like to get around it. Suggestions? Thanks

GenuineVibe · Post by **GenuineVibe** » Fri Jul 04, 2008 8:58 am

i miss the "beep" aswell, i can never remember if i locked it. I'm definatlly not mechanically talented at all though....

Bikerscum · Post by **Bikerscum** » Mon Jul 07, 2008 10:29 am

Well, while I think I could plod through the circuit for the beep, I couldn't get past the hazaard beep.... so I called in the Cobra. Steve's a guy who just lives & breathes engineering.... particularly electrical engineering. Probably made a Tesla coil from his first Erector Set. And, he shares what he knows with us less .... ummmm.... enabled. "The idea is that the RC network on the TRIGGER input will generate an OUTPUT pulse only if the input pulse is short enough to release the RESET input before the TRIGGER network times out" -Steve Woodward Here's the circuit... Keep in mind this would no doubt not be his prefered approach, but I constrained him to using the 555 chip & other bits you can get from Radio Shack, so anyone can do it. Soon as I get the stuff together, and the time, I'll post how it turns out. Thanks again Steve.