Uber-easy DIY USB ALDL Cable

[shimniok]

Okey doke... I broke out my o-scope to look at waveforms, looked fine whether vehicle running or not so that wasn't the problem. I thought it'd be interesting to try and buffer the signal with a PNP and was able to look at waveforms in that case. There may be a ground issue at play but need to investigate further and eliminate loose wiring. :) I was able to collect data during idle for about 30 seconds before TunerPro reported a data error (loose wiring, probably).

EDIT: it was a ground issue. Fixed. Data logging works at idle and engine off. Was able to collect about 3 minutes so far. Will have to test long term once I get this thing on the road. Wouldn't be too hard or costly to build my own circuit board.

Once the truck warmed up it was idling all on its own (not well, but still...) Pretty happy about that! Clearly open loop is whacked out. But this means idle is approximately stable enough to permit me to check and adjust timing. Whew.

I'm relying on Scott for the Autoprom emulator/burner until I can scratch together enough money for one of my own. I want to look into what it'd take to make my own emulator (or more precisely, some device that would permit near real-time bin changes). But all that's off topic.

Scott pointed me to this as a start for a DIY cable: http://www.aldlcable.com/sc/details.asp?item=daewoo

Pretty cheap too, all things considered.

[FSJ Guy]

That cable is just for the CABLE. No transistors or circuit inside to allow it to talk to the laptop or ECM.

The best setup for real-time emulation is the AutoProm that Scott has. The only reason I got rid of mine was because it can't burn the big chip that I am now using to stack multiple files on. Otherwise, it's an excellent device to allow emulation AND datalogging at the same time.

I'm tired of experimenting with the FTDI chips. I think I'm just going to order a cable from Moates.

[phonedawgz]

I do sell USB to ALDL cables for less.

http://reddevilriver.com/aldl.html

Yes it works out of the box.

Yes it is based on the FT232RL chip

Yes it works for both Pin E 160 Baud and Pin M 8192 Baud

It is available in both 12 pin and 16 pin (OBD2 type) connectors, and also in a bare pin format.

[shimniok]

That cable is just for the CABLE. No transistors or circuit inside to allow it to talk to the laptop or ECM.

Yes, I know. :) Hence a "start" of a DIY cable. :) Sorry for the confusion. What I meant was, you start with that handy cable, then add the FTDI stuff. I'm still working on what that stuff would be. :)

But, if you have the money to spare, IIWY I'd get some form of ALDL / USB cable pre-made like the one phonedawgz sells. Avoid the headaches.

[EagleMark]

Playing with cables and making cool stuff on the bench is fun. But if you want to record data and tune cars then cables are cheap tool!

Trying to get RedRiver to advertise here so we have good cables and someone involved to help with projects like this...

[FSJ Guy]

Yes, I know. :) Hence a "start" of a DIY cable. :) Sorry for the confusion. What I meant was, you start with that handy cable, then add the FTDI stuff. I'm still working on what that stuff would be. :)

But, if you have the money to spare, IIWY I'd get some form of ALDL / USB cable pre-made like the one phonedawgz sells. Avoid the headaches.

If you're going to do a DIY cable, you don't really need the ALDL plug. Just tap right into the wiring harness. The ALDL plug allows you to carry the cable to different vehicles. If you don't need that feature, wire it up yourself and just use the USB connector to plug and unplug it.