I got my MS-II idling in the FC last night, thanks to the contributions of this forum. There's some things I would like to take a look at on the bench, so I bought a jimstim kit from DIYautotune and assembled it this evening. The settings I have on it don't seem to be working right. The megasquirt responds fine to CLT, MAT, and TPS inputs, however, the megasquirt is not showing RPM.

I wired the megasquirt ignition to H4Inf's PDF file. I set the jimstim up with dip switch #5 on for 24/2 denso CAS, 2nd trigger to pin 31, 5v tach pull-up, and the IGN LEDs to pin 27 and 29 to monitor leading and trailing activity.

If I run output test mode, the injector and IGN leds show function, so it's only the RPM that's not working. I hooked up the LEDs to the output of the signal generator, and it's giving a signal that flashes faster with increase in RPM. The second trigger output seemed to have the same signal as the first trigger, so it leads me to believe that the denso 24/2 option does not work with our VR inputs. To get this to work, do I have to temporarily change my trigger settings in megatune? Is my jimstim setup incorrect? Do I have to program the jimstim for our CAS signal?

 

I'll have to check into that. I have a jimstim here so I'll see what I've done to get it to work. I switch between lots of different settings though.

 

Anyone ever find a solution to this? For some reason, I don't think the denso 24/2 setting on the JimStim accurately emulates the RX7 CAS. All else fails, I may get a USB cable and see if I can change it around to do so.

I'll post something up on MSExtra forums if anything else.

 

So, my suspicions were sort of correct. According to Jean on MS Extra forums, the jimstim won't work with the LM1815 circuit without modification.

http://www.msextra.com/viewtopic.php?t=26831

I'm going to try some things and report back. It would be nice to be able to trigger the LM1815 circuit so we can test them in our builds, and (in my case) play with different firmware.

 

the easiest thing to do is to bypass the lm1815 when you're using it with the jimstim.

That's what I've done on my test bench setup.

Ken

 

That sounds good, however, I think it would be nice for some people to be able to test their LM1815 circuit while doing their build.

The issue I ran into, and did not realize was D3 on my Jimstim board. I bought and assembled my Jimstim before Jean found that D3 was causing errors with the CPU generating some tach signals, I guess the Denso 24/2 signal was one of those that were effected.

I removed D3 and installed a .1uf capacitor in series with the 2nd tach signal and it now "stimulates" my MSII without having to bypass the LM1815. I think this would be helpful to those who are building a dual VR sensor MS that want to test their LM1815 circuits.

 

I just found a problem... basically trailing ignition hangs the processor. I'm debugging it right now. James rearranged a lot of the interrupt handlers and I guess this got missed.

Ken

 

OK, found the problem with trailing ignition, and fixed it, but found 2 or 3 other problems, will work on those today.

Ken