Shift light?

[Bernd Felsche]

BOWEN, SCOTT M. writes:

>I was wondering if any of you guru's have any suggestions for building a
>shift light that functions like the overpriced, ugly Autometer units. I am
>working on a custom install and those units are to big.

I'm not a guru, but how about a smart shift-light instead?  One that
knows about your engine's torque characteristics and gearing?

Use a uC.  Roll your own with engine spark and road distance pulses
(from speedometer sensor) as inputs, then a couple of output to
drive the "idiot lights". Hook up a switch; possibly in series with
the WOT switch to tell the uC to learn the acceleration
characteristics.

Find a straight, level bit of road and do in-gear acceleration runs
with WOT so that you can teach the uC the acceleration-in-gear curves.

The uC can then determine from road speed and engine revs which gear
you're in and be able to indicate/warn up/down-shifts based on
the best acceleration achieved near that road speed.

The most expensive items would be the warning lights to suit your
requirements.  uC chip cost about US$5-10. Something like an AVR
with RAM and EEPROM should be sufficient - the amount of memory
determined by the required accuracy.

-- 
Real Name: Bernd Felsche
    Email: nospam.bernie at perth.DIALix.com.au
     http://www.perth.dialix.com.au/~bernie - Private HP
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