Well, if you've had forgetting to disable ASR make an *** of you too, welcome.

Previously I've tested the ASR system and found that changing to a normally closed switch would cause the processor to sense a false/true transition on powerup and toggle the mode. In simple terms; ASR default to off.

Off I went, looking for a normally-closed switch. Unfortunately, the dirtbags at GM selected a 'tact' switch that is manufactured by everyone on the planet, but is absolutely not available in normally-closed form.

The upside of this is two-fold;
1) If a normally-closed switch were substituted, a bad connection could cause the mode to toggle unexpectedly (railroad tracks, etc.)
2) Not fooling with the switch is actually easier. What I'm now concocting is a small board that will plug in in-line with the existing switch. Essentially, you'd pull the plug off the switch, plug it into the board and plug a different connector from the board onto the switch. Easily reversible. I'm planning on using a T flip-flop to store the currently selected mode and revert to that mode on ignition powerup. The whole thing should easily tuck behind the switch pod.

Anybody interested in seeing the finished product?



[Modified by rocketfinger, 7:27 AM 6/9/2002]

 

I think that you are on the right track. However, I wonder how marketable such a product would be. Is there sufficeint interest to warrant a manufacturing run? Costs could price the units to be undesirable.

I wish you luck!
:cheers:

 

Not sure there's any money to be made here :nonod:
but you might be surprised at the unit costs in volume. We're talking pennies, but I'd post all the technical details gratis. There were 23XXX '94s built with ASR, how many others I haven't bothered to check, but I'm guessing a significant percentage of those owners would like ASR to remember where it was last set.


[Modified by rocketfinger, 7:37 AM 6/9/2002]

 

Sounds like you are on to something good there. I know when I drive my buddies 94 I wish it was automatically off. It has rememinded me many times, when you least expect it.

 

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Question: The T-flop flop would have to be powered all the time to retain
it's previous state. Correct? Granted this should not be a big deal since you
can use LS devices, just trying to understand what you're trying to do.

If you go this route, you may have to consider some type of switch debounce logic/circuitry to drive the T flip flop. The simplest would be the addition of a capacitor, but you'd have to do some testing to insure it would work. Hope you've got a scope!

There are 2 other issues you may want to consider.
The first is tha real marketability of this. In my mind, I can simply turn
off the existing swith, so why should I pay to do it as a default? The second is any potential legal issues. You would not want anyone to install your product, get into an accident & sue you due to the fact that the ASR was turned off as a default. Wether the customer was right or wrong in the use/misuse of the vehicle, they could sue anyway.

Not trying to be a wet blanket here -- just trying to explore the downside.

Fred Oliva


[Modified by rocketfinger, 7:27 AM 6/9/2002][/QUOTE]