cables for MS / megastim?
Turbo Mini Forums

I've built up my stimulator, and am about to start on my ECU using the megabuild manual.

It seems I need a lead - or a few leads - to connect all this together?

Any pointers please! I've had a look on the MS forum, but man there is a lot of info there.... (read too much info,,,,)

Edited by TurboDave16V on 10th Apr, 2007.

connecting a stim to a regular megasquirt? they jus tplug directly into each other, one has a male and the other a female DB37 :)

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

or are you useign one of these fancy missign tooth stimulators? if so you can hook a regular stim to the megasquirt, and cut the regular stims rpm trigger out and substitute your own, worked for me whilst playing wit hthe rover 36-1-1-1-1 wheels this gives you a pretty fuss-free setup

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

oh - I think I've messed up then...

I assumed I needed a cable - didn't realise that it actually plugged straight in LOL!

So, if i wanted to set up my system for bench testing the code, what would you reccomend doing?

I'll be using a RS540 motor with its own speed control to move a 36/1 wheel. I guess I could just mount some sensors and what-not to a dummy loom, and 'pretend' it's all installed in a vehicle, when really it's all just mounted on a piece of board....

hmmmmmm. :)

Edited by TurboDave16V on 10th Apr, 2007.

Hi,
Dave ... Did you look at Jeans Break Out Board? Looks just the thing for what you want to do....
Cheers,
Gavin :)

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Ding dong - well done Bat...

Have re-raised the break-out board stuff.

Dave

for what you want dave quickest and easiest setup is hook up the stim as normall. then note what trace on teh stim provides the "IRQ" signal to the megasquirt, cut this trace and then wire your crank position sensor in here. build the megasquirt up as you would for the VR input and your good to go. a few otehr small mod's to the stim and you can have flying leads comeing off to hook up to your scope for the injector and coil outputs and your ready to bench.

heres a pic of mine: cut trace just after the wee green wire, the wee green wire is there so i can hook up the stim's own trigger output if im not specifically testing a missing tooth wheel :)

excuse the blurryness but im sure you get the idea, its basically a poverty-spec break out board

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

IRQ?

So the stim board is (amongst other things) generating a 36 (without the missing) pulse ref, that I adjust the frequency of - so I just need to break into that signal line???

And what of the injector and coil outputs - can you point out to me which pin they are?

Cheers,
Dave

the stim board creates a single pulse liek a points system would create. to test toothed wheels i cut this out and substituted a signal from a crank position sensor pointing at the wheel i wish to run. when running an external wheel and sensor like this the circuit on the stimulator is defunct.

irq (Interupt ReQuest) every time the megasqurit recievens a pulse on a certain line the processor stops what its doing and processes teh interupt. in this case the classic megasquirt install would recieve an interupt every time the points opened and closed on a toothed wheel set up the megasquirt recieves an interupt on the falling edge of each tooth(where it crosses 0v), basically its another term for the wire you hook a VR sensor or whatever form of trigger you have up too.

the other wires depend on your install im afraid, as you will no doubt be running atleast 2 coil outputs etc there is wiring diagrams on teh mega manual, itll be self explanatory once you have built the megasquirt itself.

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

cheers Evo...

Keep checking back - I'll probably need your help before too long!

sorry about the typing by the way, i really should proof read before i hit post.

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

Evo,

While it's true that you can easily modify the stim, it's hard to reverse the mod and if you want to get at other signals it can get a bit messy. With the breakout board this is very easy. Here's a picture of the board connected between the stim and the MS board:

Also a small technicality, with MS2 the tach signal is no longer an IRQ signal but an input capture signal. It still cause an interrupt but it also gets the timer value to get an accurate timing between the tooth events.

Cheers,
Jean

http://www.jbperf.com/

I should have added that the breakout board can also be used for in-car diagnostics because you can plug it between the MS and the wiring harness and have access to all signals coming into and out of the ECU

You can also change some inputs with external signals if needed/desired.

Jean

http://www.jbperf.com/

wasnt bashing the breakout board atall jean, its specifically designed for the kind of thing that is going on here, and i agree, when i was benching my waisted spark setup and VR filtering circuits the stim got very messy with extra wires :)

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

I wasn't seeing your comments as bashing, don't worry. I just wanted to explain for everyone reading the thread. I've also modified my stim before I made the board :). It's just a lot easier and quicker to do with the breakout board and there's a lot more flexibility for both bench and in-car testing/diagnosing.

Jean

http://www.jbperf.com/