CAN breakthrough!

Post by **jsmcortina** » Thu Jan 24, 2008 3:51 pm

For fuel or spark on two units you need a syncronisation signal, you would probably be as well to have two units in parellel sharing the signals.

James

devojet · Post by **devojet** » Fri Jan 25, 2008 3:54 am

With CAN you could share the variables you suggest between two MS2's. This is what James's transmission code does. But as James said you will need a sycronised signal to do fuel and spark.

cheers

Daniel

Post by **jsmcortina** » Sat Jan 26, 2008 8:35 am

In the latest (CVS) code I have been able to successfully use CAN-passthrough to tune MS2/Extra while connected to a different box on the CAN network. This needed some thought due to the paging mechanism in the code.

James

JeroenBosma · Post by **JeroenBosma** » Sat Jan 26, 2008 10:12 am

So.... If I got it right, it won't work because the CAN is not a suitable chanal to sent timing sensitive signals over.

What is your oppinion ? Should I let it alone, or is it a nice idea ?

Sharing signals like MAP, CLT, IAT etc. would be a nice feature. The RPM signal sharing would give the least trouble. I might even pull the signal of the pin on MS2 and feed it to the other MS2.

It would give CAN an interesting turn....

Post by **jsmcortina** » Sat Jan 26, 2008 10:25 am

I'd persue the single ECU for as long as you are able before going to twin ECUs. Tuning will be a lot more of a pain with two ECUs.

James

JeroenBosma · Post by **JeroenBosma** » Sat Jan 26, 2008 11:33 am

I understand. And I agree. But I wan't to get rid of the distributor and running COP on an Odd fire V6. I completely agree. But dizzy odd fire is not a succes I am afraid. I am not afraid of tuning issues. Since the second proc is only doing 3 coils, no fuel.

Can you help me setting up a CAN system for 2 MS2's ? A testbench howtoo ? Or is that too early ? It would be nice to tune both MS2's over CAN as it saves me a MAX 232 circuit.

Jeroen

devojet · Post by **devojet** » Sun Jan 27, 2008 12:45 am

A Bench test set up is easy. You just need 2 MS2's and two stims. Set them up as you would if you were only testing one, then just connect CANL to CANL and CANH to CANH. The normal stim has some solder pads which are connected to the spare ports on the db37 connector.

If you load the latest Beta on both, you can veiw the ADC inputs on one MS2 via CAN on the other one connected to megatune. If you right click on the gauges to change the gauge you should see and option for GPIOADC.

Another one you can try out is load one MS2 with the latest MS2extra beta and the other one with James's Transmission code. you can then connect megatune to the one running MS2extra and view and tune the transmission via CAN.

What you want to do will require firmware mods but might be possible if you share the RPM input and pass the rest over CAN. James would have a better idea than me on wether or not this will work though. It is very interesting though.

Cheers

Daniel

JeroenBosma · Post by **JeroenBosma** » Sun Jan 27, 2008 6:27 am

Thanks. I have quite a supply here so I am in for a bench test.