An Engine Simulator is Born - Part 1

[S2central.net]

peculiar is a good word alright - LOL... these things keep me out of mischief - well most of the time

[Flat on my back]

.

All 'geeks' are built that way...

Top job Paul.

[mcandmar]

Fascinating stuff Paul, keep it coming

Is the ITT chip where the speed correction takes place? I remember seeing a coding block and dip switches on the back of the cluster for this purpose. Any chance you can tease out which does what?

Reason i ask is the speedo in my CQ20v reads slightly fast as i have an ABY cluster in the car. Cant figure out why it reads fast, same wheel size as an ABY and the speed sensor is on a gearbox output shaft

[johne]

Fascinating stuff Paul, keep it coming

Is the ITT chip where the speed correction takes place? I remember seeing a coding block and dip switches on the back of the cluster for this purpose. Any chance you can tease out which does what?

Reason i ask is the speedo in my CQ20v reads slightly fast as i have an ABY cluster in the car. Cant figure out why it reads fast, same wheel size as an ABY and the speed sensor is on a gearbox output shaft

The DIP switches on the back of an S2 cluster are for calibrating the mpg computer & its display.

John

[S2central.net]

johne is right there... the speedo module just has four pins (not necessarily in this order)...

1 = 12V
2 = G22 in
3 = VSS out
4 = 0V

AFAIK - all dashboards read about 10% high anyway - have compared a few with GPS and always found that to be the case.

[S2central.net]

Few important additions to the overall scope drawing...

[S2central.net]

And the outline design for ESIM Part 1... I won't bore everyone with all pinouts and minute details here - its pretty self explanatory but I will be recording everything as I go.

[prj]

Pretty neat project...
I wonder if it is possible to just log all the data from the entire wiring harness from cold start, drive around a bit, then simulate the thing to the ECU?

[S2central.net]

Well - part 3 could be quite cool with a programmable DAC that could replay some logged sensors (needing a multi-channel ADC to log all that data in the first place) - say from a cold start, some hot runs or whatever... But that is some way off - there is probably some exotic piece of equipment that could help but I don't have the funds for such a luxury.

[prj]

Aren't 8 channel ADC's with serial outputs a couple of dollars each though?
As in http://cgi.ebay.co.uk/AD7908-8-Chann...item2305be4926
Or am I missing something obvious?

[S2central.net]

Well - maybe... lets park that for Part 3 - lots to do before we get there

[S2central.net]

Bit of an update... more elaboration for Part 2 - I had done much of this in the past - I need to revisit the HLD for G4, G28 & G40... I will probably use audio software to generate the sawtooth wave for G28, but will look for alternative means as well - ideally something that can change the o/p frequency by varying a voltage input control... that keeps the door open to DAC controls in Part 3 someday in the next millenium.

I will be OK designing the counters to trigger G4 and G40 but I might need some help making a pulse that looks like G4. Need to blow the dust off some old cookbooks. Tis all good education for my young assistant as well

Cheers,

Paul

[S2central.net]

Also - more of a formal write up on the G22 simulator prototype for Part 1.

I might lash up another one tonight that runs towards Vmax on the speedo. That will be as fast a speed as I have ever seen - except on Gran Turismo - LOL

[prj]

You have no life
Just kidding...

Looking great, keep it up.
Regarding audio software - if you have a programmable DAC, why do you need it? Wouldn't it be easier to just code some simple app to interface with the DAC directly?

[S2central.net]

Feel free to contribute to this project on such ideas - anyone. I'm hoping not to have to do all the work here ! Lol...

I have tried to carve it up in slices so that it is easier to collaborate on things so that all the ecu dabbler can get somewhere.