Ignition signal seems backwards with JimStim lights on

[fasterlaster]

I am building my first MS and for the most part it's been a very smooth assembly, but I have run into one hurdle related to the ignition output. I'm at work so I don't have access to post my msq and datalogs, but will be doing so soon. This initial post is more to see if anyone has an ah-ha idea to point me in the correct direction.

The Problem: With the JimStim connected and running the injector LEDs flash as I would expect. The 4 LEDs I have jumpered to my ignition output act the opposite. When in test mode in TS selecting 'off' will light the LED up, and 'on' will turn it off, as if it's backwards. The behavior of the flashing also looks more like it's always one with brief interruptions of off instead of the other way.

More Detail

• Testing the JimStim manually shows a signal on both primary and secondary Tach, so I believe Stim is 100% functional
• running 36-1 input TS reports full RPM sync
• I will be using a QuadSpark to power 4 COP units.
• Following the instructions in Section 3.3.3 for a QuadSpark, I assembled the recommended logic circuit in 5.3.1.3. This is the circuit using TC4427AEPA FET drivers.
• For the cam input I followed 5.2.14.3 Adding a cam sensor input - hall or logic sensor, the jimStim is set to 5v pullup on the secondary Tach. There are multiple cam sensor inputs, so that may be my issue. I'll be trying the 5.2.14.2 circuit later today now that i have some spare resistors needed for that circuit.

Update added the msq and msl files

Basic Info:
MS2/Extra 3.4.2
V3.00 PCB
TunerStudio
JimStim V2.0.4
(real data in msq and datalog to be added later)

[fasterlaster]

I had the opportunity to actually hook up the 470R resister that jumps between OptoIn and 5V on the proto circuit per 5.2.14.2. No change in behavior with the LED on JimStim. I've also hooked up an oscilloscope to the ignition output. It looks like I'm getting a 5V signal that lasts for ~4.6ms. I'm assuming this is the dwell and is close to what is set in TS. I think this means my ignition circuit is correct and the QuadSpark will be triggered by a going high 5v signal, but I'd appreciate a more knowledgeable opinion.

[jsmcortina]

The LEDs are switched on the ground side - so work "backwards" to the way you may expect for an active high ignition output.

You can test a couple by using the "IAC" LEDs with one side connected to ground and the other to your ignition output.

James

[fasterlaster]

Thanks James! That explains a lot. I ran across similar comments from you in the archives, but I didn't quite understand what it meant till applied to me. I can't wait to get home and try the IAC LED.