Zach's Carbs to Microsquirt conversion thread, 7/20/18 update Options

[Spoke]

So right now this is my plan for the test board.
(IMG:http://www.914world.com/bbs2/uploads_offsite/farm9.staticflickr.com-1435-1428018341.1.jpg)

Please look and see if I have something glaring. Do I need to add a circuit?

I think I only need 3 circuits at this time.
1) Power
2) Coms
3) Bootloader Ground

I have a 15 volt, 1.4 amp power AC to DC power converter on hand. This will allow me to plug the test box into a wall and not have to fiddle with batteries.

The numbers inside circles are the pins to the Ampseal jack.

Boot loader will be on a switch instead of plugging and unplugging a wire, with an LED to show when it is grounding.

Zach

If pin 1 is the power pin, the LED should not be in series with it unless the manufacturer says so. If you want an LED to let you know when power is on, the LED should be connected between the switched power and ground through a resistor of about 5-10k ohms.

A couple of things from previous posts: You 'may' be able to see some resistance from power to ground with the power off. If it was a dead short, it would show up as zero ohms. This is not a conclusive test.

About the power supply noise, chances are the automotive voltage rails are about as noisy as can be. The electronics in the MS run off a low voltage like 5V or 3.3V or lower and likely have significant filtering from the input power to the conditioned digital power.

Still a good idea to have as quiet a power supply as possible. If you're going to have a fuse in the path, why not use a car battery? The load on the battery has to be minor and should give hours of running just the MS.

[VaccaRabite]

I don't have a spare car battery. My 914 and its battery are at Tony's shop.

[Spoke]

Your power supply should be ok.

What exactly happened that the MS stopped working? I read through your thread but couldn't tell when the ECU stopped working.

I'll offer to take a look at it and see what's wrong. We do electronic solution development at work and have a lot of experience with small systems like MS.

Here's one we just finished. It's a camera on a needle for probing knees and shoulders. Pretty cool. We did the camera board (me) and the base processor and software. It runs Android. (IMG:style_emoticons/default/barf.gif)

Trice Medical Mi-Eye

[crash914]

Schematics are available here...

http://www.microsquirtmodule.com/microsquirt_V2.2_module.pdf

[crash914]

it could be just the rs232 chip that is no good....

[McMark]

Careful of changes by version. That schematic is v2.2, the ECU is v3.

[crash914]

yea, i thought about that.....ver 3.0 is also available...

[VaccaRabite]

Your power supply should be ok.

What exactly happened that the MS stopped working? I read through your thread but couldn't tell when the ECU stopped working.

I'll offer to take a look at it and see what's wrong. We do electronic solution development at work and have a lot of experience with small systems like MS.

Here's one we just finished. It's a camera on a needle for probing knees and shoulders. Pretty cool. We did the camera board (me) and the base processor and software. It runs Android. (IMG:style_emoticons/default/barf.gif)

Trice Medical Mi-Eye

I don't know. I was not there. All I know is what was stated. They had it connected, ad then it stopped communicating.

Could I get you to draw out the circuit (so a dummy layman like me could build it) so that I can have the LEDs light up when there is power to their circuit?

Zach

[Spoke]

Schematics are available here...

http://www.microsquirtmodule.com/microsquirt_V2.2_module.pdf

Thanks but the link just takes me to a logo.gif file. I looked on the MS website but still didn't find the schematic. Got another link to the schematic?

[Spoke]

Could I get you to draw out the circuit (so a dummy layman like me could build it) so that I can have the LEDs light up when there is power to their circuit?

Zach

Here's the main part of the circuit. The LED with the bootloader is not in the right place but I don't have a schematic to add this to it.

When you connect the power from the wall wart, do not connect the MS to it yet. Connect the fuse, switch, LED and resistor and try the power. If the LED doesn't light when you close the switch, the voltage is backwards. If the LED lights when the switch is closed, then the power is correct. Then turn the switch off and connect the MS.

When you're done with this and it doesn't work, you can give it to me and perhaps I can get it running and give it to you at Hershey. BTW, I pass through Harrisburg 2 times a week if you want to drop it off.

[McMark]

I don't have a spare car battery. My 914 and its battery are at Tony's shop.

Motorcycle batteries are pretty cheap and make great tester batteries for all sorts of automotive projects. (IMG:style_emoticons/default/wink.gif)

[crash914]

Let's try this one.

Never mind......can't cut and paste

[VaccaRabite]

Herb, i may come to pick your brain when I get the tester built. Youve done this before and that may come inhandy trying to get the ECU back on line.

Zach

[crash914]

No problem...Jim stim and unit on my bench. I think I have everything to fab a cable if needed...

[VaccaRabite]

Well, I built the breadboard for the power circuit, and found an issue.
My 15 volt power supply (which would have been perfect for this) is actually a 20 volt power supply. Glad I checked it with a multimeter before connecting the MS unit.

Microsquirt can take a 9V to 17v supply. Looks like its time to go get a lawn tractor battery. At least I'll have a hot spare when the battery on my tractor dies.

Zach

[VaccaRabite]

Tester for power built.
(IMG:http://www.914world.com/bbs2/uploads_offsite/farm8.staticflickr.com-1435-1428808725.1.jpg)

tested with the meter: 12.68 volts. In business.

Attach the leads and put 12 volts on the Microsquirt controller. No problem.
Turn that off, and go to hook up laptop.

Zach

[VaccaRabite]

My laptop has sucessfully communicated with Microsquirt!!!!!!!!

WOOOO!

(IMG:http://www.914world.com/bbs2/uploads_offsite/farm9.staticflickr.com-1435-1428809738.1.jpg)

Now I just need to figure out why it won't on my car... My laptop detected the microsquirt ecu within second of plugging it in, so I know the ECU is good. I also know my laptop is good.

Harness? Ground loop?
zach

[VaccaRabite]

So here is my theory.

This test circuit only has power and ground and communications. Nothing else is hooked up.

I recall in the startup file I was reading again last night it said to unhook all the sensor leads and make sure they are not grounding anywhere. I bet this is the issue. The leads are unplugged but were just laying in the engine bay. I bet they are grounding and creating some sort of connection problem.

The other possibility is a fault in the harness. Maybe a bad crimp somewhere. Though I tested continuity on the harness and I got a solid tone each time, so this is not a strong theory.

Wont know till I can get back to the 914, which may have to wait till after Hershey - depending on Tony's schedule.

Zach

[VaccaRabite]

Brain goes back in the catr on Thursday for further testing. I had taken thursday off for Hershey anyhow, so this will be good timing.

Still, excited that I was able to get my laptop to talk to it, eleminating the ECU and my laptop as the issue.

Zach

[VaccaRabite]

No dice. Once in the car the ECU failed to connect again. I pulled everything that could be causing a ground loop out, still no love.

Finally pulled the wire harness to bench test at home. I may do this tonight at the Knights Inn, since the whole mess is in my car already.

Stuff I tested: there is power for sure. 12 volts.
Grounds are clean. Grounds go from the engine block to 1 place on the engine harness - so we should be getting a clean ground to the ECU.

The harness is the only thing I can think of at this point that would be causing a problem. Hopefully I will be able to figure that out tonight or tomorrow.

Zach