festy's Alfa Romeo Alfetta GTV

[UCMatt]

Hi Festy,
I am keen to give one of your boards a go - I have an immediate application.
I don't need it packaged.

Cheers,
Matt

[festy]

I've been playing with scaling the VSS signal up and down, results are looking promising:
(blue = VSS in, yellow = scaled signal out)

PPK reduction (division):

2:1 ratio

2d.jpg (55.31 KiB) Viewed 3848 times

4:1 ratio

4d.jpg (55.83 KiB) Viewed 3848 times

10:1 ratio

10d.jpg (54.72 KiB) Viewed 3848 times

PPK increase (multiply):

1:14 ratio, trying an odd ratio

14x.jpg (54.76 KiB) Viewed 3848 times

1:20 ratio

20x.jpg (55.3 KiB) Viewed 3848 times

I'm hitting a few issues with both measuring and generating really low speed pulses, but I think I should be able to sort that out...

[Holden202T]

yeah i too would buy a basic board and i don't need a box or anything

[festy]

This might not look too significant, but...
The blue trace is a square wave, like a hall effect sensor would produce, and the yellow trace is the square wave output from my reluctor amp board.
This signal is being converted from a hall effect to a reluctor type, then back to a hall effect, eg. a universal converter .
The "reluctor" waveform in between the conversion stages doesn't look much like a sine wave, but it's triggering the zero crossing detector pretty well as shown by the input and output signals staying 180* out of phase.

thereandbackagain.jpg (49.76 KiB) Viewed 3818 times

[festy]

So I've been working on this in my spare time, and finally got around to installing it in my poor old Patrol yesterday. It's speedo has always read about 10km/h fast, so a perfect test candidate

My speedo corrector can take either a hall effect or VR (reluctor) sensor as input and can emulate both types, so will work with either as well as convert signals from one sensor type to the other.
The "correction" amount is done via a pair of trimpots - one for coarse adjustments and one for fine tuning.
There's 2 adjustment ranges - roughly 3:1-1:3, and 10:1-1:10.

My Patrol uses a VR type VSS, and now reads only about 1km/h fast at 80 so I'm pretty happy with that result

speedo_corrector.jpg (182.46 KiB) Viewed 3716 times

[VL400]

Nice work, the board has turned out well!

[HQ355]

Hi Festy will you still be making these available for sale ? I'm still interested

[Holden202T]

yeah nice work!

1km is good enough, and a hell of a lot better than the 10 you had before!

[antus]

I agree, that has turned out well

[festy]

Nice work, the board has turned out well!

Haha thanks, but I don't think I should give up my day job any time soon though

Hi Festy will you still be making these available for sale ? I'm still interested

I still need to do some more testing first, I'll PM you as soon as I'm done.

1km is good enough, and a hell of a lot better than the 10 you had before!

Being "only" 10km/h out already made it one of the most accurate speedos I've ever had
I really didn't want it any closer, and certainly didn't want it reading slow at all...