Okay, i'm having problems getting a VR input.
The moment i have megatune change to "Generic Wheel" i no longer get any type of rpm. If i leave "Generic Wheel" off and spin the cas i get an rpm signal.

Any guesses as to what i screwed up?

EDIT: Also, the RPM reads 2 when connected and nothing else. I thought it should read higher then that?

 

did you set up the wheel decoder settings as given in the FAQ? with 2nd trigger?

If you got rpms without the wheel decoder set up, you weren't really getting anything useful except that the built-in vr sensor conditioner works.

 

Yup, i have it set to 2nd trigger and it's not getting anything.
I'm going to try to test the circuit i built by connecting 24wheel to it and see if i can get anytype of output. I should get a 5V out that's going to the CPU right?

Okay, i connected the VR circuit i built to the 24wheel and received a +0.3V at the max on pin 11 on the CPU. That's certainly not right is it?

 

it'll be a +5v square wave. It might show up as a voltage fluctuation on a multimeter; on an oscilloscope, it'll show up as a +5v square wave.

did you connect your circuit to pin 11 on the cpu? are you sure your G+/G- wires are connected properly?

Ken

 

Well i have G+ going to the Vr2in, VRout is going to what is labled jumper8, which on the 3.0 board goes to pin 11 on the CPU

I have G- wired to Ne- and both of those wires going to pin 7 (this is a S5 case, though i don't think it should matter).

 

You should probably ground G- as close to your lm1815 circuit as you can... although I'm not sure that's what is causing your problem. Also, I usually wire the output of the lm1815 circuit through a 1k resistor to pin 11 of the cpu. If you're getting no rpms after switching to the wheel decoder, either your software setup is incorrect, or your lm1815 circuit has some sort of error. If you set it up exactly as in the FAQ, then most likely the error is in the circuit itself.

 

Well i think i might have a larger problem. The ECU isn't responding to to anything from the stim and it says the voltage is 22V instead of the 12V that i know it is. I can't flash it either.

I think i might have fried the CPU...lol
Never mind, i got it to work.
Well the CPU to work...not the VR Circuit.

 

well, just double/triple check your circuit, and then if it all looks good, you may have overheated the lm1815 while soldering... I've never done this myself, but it seems several people have managed to do that to the lm1815 even when they didn't do that to other chips on the v3 board.

Also, before doing anything to the hardware, make absolutely sure you have the right settings for the wheel decoder. Make sure the built in vr sensor conditioner potentiometers are both set all the way counter clockwise. Be careful when turning them as if you're turning them too quickly, you'll click past the stop without realizing it.

 

Woohoo! I got it to work!
I redid all the wires that i had going directly to the grounds and +5 with slightly better wire and it's working now.

Thanks very much Muy!!