MPGuino release one workspace - Page 3 - Fuel Economy, Hypermiling, EcoModding News and Forum

MetroMPG · 05-09-2008, 08:49 AM

Well, if you mean: "what's the best way to connect to the wires that connect to the relevant pins", have a look at dcb's first image in post #18. He's using those "splice clips" (not sure what the realy name is.)

(Hmm.. splice... if there were a bunch of women electricians playing in a band, would they be the Splice Girls?)

dcb · 05-09-2008, 09:51 AM

I went straight to the ECU. A few posts back, I had located the pinout for my ecu and circled the connections needed:
http://forum.ecomodder.com/showthrea...5.html?p=23551

I just tapped into the wires coming out of the ECU plugs that corresponded to those connections, and hooked them up to the guino. Battery and ground went to the power plug (center pin positive please), the vss signal went to the vss-in on the guino and the injector signal went to the injector-in on the guino.

Note: you need to choose wire size carefully when using the spice clips or they won't connect to the wire properly. I had to replace the yellow hookup wire since it was a fraction to small and wasn't making a connection.

If you don't have a pinout, don't despair. We are really only tapping into one side of an injector (easy to locate, and only two wires to choose from) and the vehicle speed sensor, which is a little more tricky (may be in the speedo or the transmission). And of course battery power and vehicle ground will be hard to miss. I'm sure there is a generic connection routine that could be written using a multimeter, but someone has to write it. I.e. turn on the ignition, unplug an injector connector, look for 12 volts on one of the connector pins, use the pin lead that does not have 12 volts for the injector signal to the guino, etc..

larrydag · 05-09-2008, 09:57 AM

I figured you just spliced in but I wanted to be sure. I do have a pinout diagram. It's not hard to find one for Hondas. They are everywhere on the 'net using Google.

I assume unplugging the ECU won't affect the electronics of the car, will it?

(PS: Metro, and one of them is Sparky Splice?)

dcb · 05-09-2008, 10:11 AM

Quote:

Originally Posted by larrydag

I assume unplugging the ECU won't affect the electronics of the car, will it?

assuming you plug it back in after making the connections, it shouldn't be a problem

larrydag · 05-09-2008, 10:21 AM

I've read on other forums that it would be wise to unplug the negative terminal on the battery. I'll probably do that. (Have to reset the radio again, drat)

dcb, When I downloaded the updated script for the Opengauge I wasn't getting a clean display. The top row of "0" digits were all garbled. The bottom row were fine. All of the display names you created ("IN, M/G, CU, etc") were fine too. Have you seen this before?

dcb · 05-09-2008, 11:02 AM

Quote:

Originally Posted by larrydag

dcb, When I downloaded the updated script for the Opengauge I wasn't getting a clean display. The top row of "0" digits were all garbled. The bottom row were fine. All of the display names you created ("IN, M/G, CU, etc") were fine too. Have you seen this before?

I have mentioned it before, the lcd does not always reinitialize properly after a download for some reason, or sometimes when plugging into the usb port. pressing reset should clear it up, and I haven't seen it happen when just using the external power jack (i.e. in the car). Also, I started having issues with the download on the serial board, but when I unplug the 5volt lead from the arduino to the component board before downloading, and plug it back in when I'm done, it works fine. That seemed like a manageable workaround to me for now.

larrydag · 05-09-2008, 11:47 AM

Quote:

Originally Posted by dcb

I have mentioned it before, the lcd does not always reinitialize properly after a download for some reason, or sometimes when plugging into the usb port. pressing reset should clear it up, and I haven't seen it happen when just using the external power jack (i.e. in the car). Also, I started having issues with the download on the serial board, but when I unplug the 5volt lead from the arduino to the component board before downloading, and plug it back in when I'm done, it works fine. That seemed like a manageable workaround to me for now.

Ok. That's interesting. I've tried resetting it several times after downloading. I will give the 5V unplug a try to see if that clears it up. Just curious if you were getting the same symptoms. The curious thing is the initial "OpenGauge MPGuino" comes up fine but the top zeros are garbled. I'll troubleshoot some more to see if I can get it to properly initialize. I probably won't get to it until late Sat. nite though.

dcb · 05-09-2008, 08:55 PM

Ok, just a couple q's when you get to them and before I forget them.

You got the LCD from NCK, correct? I don't know if any others would be significantly different or not, and don't want to know just yet.

Can you run it on just external power (i.e. a wall wart of 9-12 volts DC with a plug that fits and center pin positive, or that 9 volt battery trick)? Don't forget to move the jumper. Does it display correctly connected to just external power?

Have you triple checked the wiring against the diagram? I'm pretty sure the diagram is correct because I used it to swap in the serial board.

What if you disconnect pins 2,3,14,17,18,19? if disconnecting them all helps, is there a combination of pins or a single pin that the problem can be isolated to? Hit reset bewteen pin connection tests so the LCD will reinitialize.

Curious that you are seeing the opening screen, but the next screen is garbled. I tried to tighten up the lcd timing, we might have to try loosening it up a bit if nothing else is working.