I have enough to make 3 more if anyone wants one.

I will caution though, it helps to have a recent laptop with USB 2.0. Some people have had problems with the driver not being recognized on old hardware.

 

bump

 

bump

 

bump, couple left.

 

Will this work for the 93 cars with the old style aldl? Thanks

 

No it will not. Sorry, 94 and 95 years only.

 

I think I need one of these. Do you still have one?

 

Yes I do. If you'd like send me a PM and I'll give you my paypal and what not.

 

Still have some left, I might make a second version/batch if them people still want them.

 

Available?

 

Yes I still have a couple. PM if you are interested for payment and shipping address and what not.

 

It's hard to tell in the videoso I may be wrong but.... from what I can see it looks like you're using a Microchip MCP2200 USB UART and a couple SOT23 (89?) transistors for level translation I assume. Some of your issues might be due to this. You'll get a lot better results if you go with a max232 RS-232 buffer instead of transistors and possibly even an FTDI part.

 

That is correct. If you are talking about the issue with USB on some old computers not working it has nothing to do with the transistors. The MCP2200 can be hooked up without/independently of the transistors, and in fact is tested that way before I continue soldering the rest of the board.

Sorry if that's not what you were talking about. I'm always open for constructive criticism, though.

On another note, I did make a max232 based connector also that used a DB9 and cigarette lighter versus USB power. After going that route, though (using this design), the max232 still gets its reading from the car buffered by transistors, after being knocked down to a 5v signal (same as USB voltage) from a 7805 regulator.

At the bottom of OBD Diagnostics, Inc. - ALDL Circuits they state they have not seen a max232 circuit where a two-transistor circuit will not. Since they have tested more cars and cables than me I am inclined to take their word for it.

I don't mean this to be any form of attack on you MikeGyver, I am mostly explaining this for people who might be curious/not know these things.

 

I'm not especially familiar with the MCP2200, but I recommend the FTDI uart because it supports legacy hardware so it may solve your usb issue. Which boardhouse did you go with btw?

 

Ended up using Itead Studio, similar and virtually the same as Seeed Studio, if you're familiar with them. Had 5 orders from them and have gotten only one bad board (out of 54 boards). I used them to fab weather station boards that I use to monitor weather when I am racing, and they did a nice job on routing islands on the boards with minimal clearance.

Microchip has all their documentation on their website for the MCP2200. It's actually a very sleek chip.