why do things not work

[tjrock]

So I know pin 1 is getting 12 volts, and all three grounds are properly grounded, but I plug in microsquirt, and I can't get it to communicate with my computer or megaview (I'm not sure megaview works with microsquirt, but I would assume it would). Where do you start to troubleshoot if microsquirt doesn't even seem to turn on. Portcheck won't even find microsquirt. I really don't want to open the board up because I fried megasquirt II messing with stuff like that, and I bought microsquirt hoping that I wouldn't have to deal with any board circuitry, but now this guy isn't even working...

Thanks in advance for any help,
TJ Rockefeller

[tjrock]

In response to my own post, I think I isolated the problem to a bad R232 to serial cable, or whatever that headphone jack is called. Microsquirt is now at least communicating with my computer, but now there is no tach signal. I'm using a hall effect type sensor (equinox cam position sensor), and let me see if I read the tach install correctly. OPTOIN+ is going to the sensor wire and OPTOIN- goes to ground, and the sensor uses a 12V reference. Is this correct, or is OPTOIN- an inverting option, and the ground should go with the rest of the grounds on the white/black wire ground sensor?

Hopefully I will figure this out soon,
TJ Rockefeller

[Matt Cramer]

That's how you should wire it up, but some Hall effect sensors need a pull-up resistor. Try putting a 1K resistor between the signal and 12 volt terminals of the sensor.