Forced_GTA

I just got a 486/25 Mhz laptop for free, and tried out Craig Moates Software (looks great!) and only for the reason that I am sick of spending so much money on my car and out of fear of going into more credit card debt, I figured I could cut costs and afford to buy all the other things (like a chip burner & eraser ) that I currently need for my car by not spending $65 on a cable I can make for a few bucks.

I looked on all the sites listed in traxions article about making your own interface, and found a couple different versions. AKM's schematic says its geared towards 94/95 cars.. and it looked like the most complicated.

This one I got looks like it will work with Craig Moate's software:

http://www.techedge.com.au/vehicle/aldl8192/8192hw.htm

To make it, it looks like all I need is:

1 MAX232
1 Voltage Reg.
3 Diodes
6 Caps
Some resistors
Wire
A printed circuit board
25 Pin Male/Female Connectors (or 9 Pin)
(2) RS-232 Cables

It looks like at school/work I can pick up all the parts I need except for the circuit board, the Voltage Reg, MAX232, and the 25 or 9 Pin connectors... so it looks good as far as cost, i'll even pick up the RS-232 cables for free. Will this schematic work with craig's program?

I have an old ALDL Connector sitting around so I am going to use that to interface the 25/9 pin cable to the ALDL test port...

Any thing I am forgetting?

Any help, suggestions? Anyone built their own cable?


------------
1989 GTA - 305 LB9/ 5speed
Paxton SN2000 / NOS 5151
Bunch of Suspension
Bunch of Little Stuff

[This message has been edited by Forced_GTA (edited June 05, 2001).]

Craig Moates

Power for your laptop (inverter or real good battery) ($30). ZIF extension for your EPROM if you're going to do alot of burning ($15).

Check my site for a couple schematics, one of which is a MAX233 design that is simpler. You should be able to get all but the MAX232/233 and maybe a couple diodes at RatShak. For those items, just check /w/ your local Yellow Pages under electronic parts, call around, and custom order if you have to. Total parts bill for the whole interface should not go over 10 bucks. Be a little higher than mail-order, but saves you some margin on shipping minimums for such a small quantity. You might check with Steve Ruse or Andrew Mattei and see if they can get you just the circuit board, since that'll let you make it clean. Personally, my interface is the 233 design size-minimized with custom enclosure (windings of electrical tape). Just used a square-grid PCB from RatShack, sketched layout, and made connections and 'traces' with globs of solder and resistor lead trimmings. Used a DB9 on one side (card-edged) and RJ-11 on the other (superglued on) with hard-wire to a phone jack at the ALDL. I also added a 3-position switch to allow A-B bridging mode selections (open, 10K, short).

I've had both the designs that are posted on my site working just fine. I'm sure that Peter's techedge design will work as well. In fact, I really like the setup he has which does both 8192 and 160. Something like that might become necessary as 160 capability is added to the program... Perhaps just a minor mod to the other designs...

Anyone have designs that work using the MC1489 as a basis? I've got a few of these now, and wondering about applications ;^)

-Craig

CanadianBeast

Ifyougo to Maxxims website, can't remember the adress, and find a link to some trials, fill out the formand they will send you a couple max232's for free. This is what I did and they sent me acouple max232a's nd Ibuilt thecable you have a link to, and it works well with Craigs program. You don't need a PCB, it's not that complicated, just lay the 7805 on top of the max chip and soldier all the capacitors and resistors directly to the max232. wrap the whole thing in electrical tape. Using a db9 connector this keeps the bulk of the cable down, which is nice.
Good Luck

AlexJH

www.maxim-ic.com is the address, you click on the samples link near the top right part of the page.

Forced_GTA

Heh.. I already went on Maxim's site and ordered a MAX232 because I read about that in another post.. but I don't know how long it will take to come. I'll order a Max233 too. The Max233 has the capacitors already built in, huh? Well I might just buy the MAX232 or MAX233 because I am really impatient. I havn't checked your site yet Craig, and since I will be using your software I will use your schematic for the RS-232 interface.

By the way Craig, I really like your software (at least from what I read in the instructions, and saw in the non-interfacing demo). It is exactly what I wanted in a data reading program.. a simple interface with everything included that I can modify if needed! The 0-60 and 1/4 Mile stuff looks great too. I am going to try using that at the track and see how close I get. I can't wait to use it!

Craig, a few quick questions about your schematic:

1. The pin 9 on "PCM I/F DLC Plug" goes to the data pin on the aldl, "M" correct?
2. R1 is 300 Ohms?
3. I can use the ground on the ALDL or any chassis ground I am assuming.
4. I can pull the 12V (VCC) from anywhere I want I assume?
5. So I really only need to connect one pin on the ALDL?

Thanks!


[This message has been edited by Forced_GTA (edited June 06, 2001).]

Craig Moates

By Thirdgen for Thirdgen...


Quick disclaimer, the schematics on my site aren't by me, I picked them up around. One's from andrew, the other I forget. They should work equally, along with Peter's design.

Answers to questions:
1) Correct. M or something else depending on year.
2) Correct.
3) Correct I'm pretty sure. I just tied chassis/batt gnd to analog gnd on the ALDL to be sure, might wanna think about it.
4) Correct, might wanna do it from an unswitched source (cig lighter) so comm goes uninterrupted during startup etc.
5) Incorrect to some extent w/r/t ground cross option. Also if it's a MAF-165 you'll need the switch/resistor/whatever to give yourself an open/10K option across A-B.

I hope that's all clear. Good luck!
-Craig
2)

Forced_GTA

Thanks Craig..

I went to the electronics store, and all they had was the MAX232 unfortunately.. if the MAX233A comes anytime soon I am going to use that cause it's a lot less complicated. I bought it and all the stuff I needed to make it w/ the 232 though. I put it together, but the 9-pin connector I got sucks, so I have to go back and buy a cable, or grab one from an old mouse or something.

I got a ZIFF too.. expensive! It was $10.50. I also picked up some PC motherboard for $.50 with 3 EPROM's on it, but I found out they are too big (256K) so that was kind of useless. Oh well, I'll let you guys know when I get it working.

Craig Moates

1) You can use the 256's just fine, just double up on the code as has been described around here, read up a bit...
2) Yeah the ZIFs are pretty high, take care making that cable or whatever you do to go from the ZIF to the ECM, should be short & sweet.
3) You should be able to make a SWEET little 9-pin deal, either with a 'solder-cup' connector (straddle the edge of the PCB with a trick mounting, works good very compact) or a pig-tail off a hooded assembly. In retrospect, I'd advise the pig-tail. That way, all you have is your 'cable', the laptop, and the 232-ALDL/pwr leads.

Sounds like you're snapping to it! Have fun..

94ZRagtop

Hi Guys,

The theory behind Peter's circuit is solid. It ought to work fine, at least on 8192 baud. I've never gotten it to work on 160, but maybe that's just me, others have reported success. I've provided some folks with the 160 baud modification (you'll notice that the circuit is independent of the 8192), but again, I've never verified that it actually works.

The easiest circuit to build is actually found on http://www.andywhittaker.com - the "two transistor" circuit. I've got a modification for it that reduces noise interference and also draws on port power (if you inspect my drawing, and then adapt the port power stuff, as well as the two diode drop, and incorporate it in there, it works). The software has to support port powering a device, though (ahem, Craig ).

However, the reason I don't go with Peter's or Sanjaya's is simply statistics. Both present "problems" for me in the LT1 world (the 95-97 cars have some interesting twists). That's why my diagram is "targeted towards LT1 cars" - because I know it works. But for a DIY job these others will work. I'm just concerned about returns, unhappy people, etc. so I go for the "slam dunk" proven circuit. For the TPI cars (which are nowhere near as finicky as the later cars), the simpler circuits will work fine. Just don't forget the 10k resistor between A&B!

Cheers,

Andrew

Craig Moates

Yep, yep, yep... I never even figured out the DSR 5v need. I don't know if the QBasic com routines I've used are versatile enough to cut it. The port-power is definitely the most elegant solution, though.

If I ever get the 160 stuff to work, I'll post it here first...

Greenshamrock77

What is the story on Craig's program? Is it free, if not how much? Where is a link or whatever to your site for info download?

------------------
82' Z-28. 327" w/ flat tops. 216/228/112LS. Pocket ported 041 heads 1.94/1.50 SS valves. World Class T-5 from a 91'. Best run? Runs with 2001 vette to 150mph! Soon to be converted over to TPI w/ supercharger.

John Boy

iTrader: (3)

http://members.tripod.com/moatesenheimer/gmecm/

Forced_GTA

94Z- I have read through your entire web page, and it is really helpful and has a lot of good info. You're car looks great too!

Are you serious that the diagram w/ two transistors, a diode, and some 10K resistors will work w/ Craig's program and the 8192 baud MAF ECM's???!?!? I am going to return my $10 worth or electronic parts and go buy those parts (about $2) if this is the case!

Will I get noise with that circuit though? On Andy's page, he mentions maybe needing to ad two diodes (like 1N4148?) in series with the 10K resistor going to the base of the upper transistor.. would I need to do this?
I assume the 2 diode drop would go before or after the 10K resist (does it matter)?

The 2 transistor diagram seems a lot simpler and less prone to fail (fewer connections) the only thing that looks different is that the ALDL connectors on the LOTUS are different (get data/12V/Ground from different sources) but I know which ones are correct.

Since Craig's software doesn't work w/ port power coming from the cable (doesn't bother me, i just want the software to be simple and work) I am assuming that I would not need to modify the circuit in any way to make it work? Would I just follow that diagram exactly and just add a 12V and ground source from the car (so I would not get those from the A & B ports then ) and then put a 10K resistor between the A&B ports?

Would the two diode drop addition be neccesary? Would anything else need to be done since i get the power externally?

Here is a link to the diagram I believe you are talking about:

http://www.andywhittaker.com/ecu/aldl_hardware.htm

it's the first diagram.

This stuff is pretty exciting, I can't wait to start burning chips. I am just trying to make the RS-232 interface correctly.

Thanks a lot for any info.

[This message has been edited by Forced_GTA (edited June 08, 2001).]

Forced_GTA

Anyone ever made the interface using the 2 Transistor method?

94ZRagtop

I was going to email ya, but you don't show your address. I don't get around here very often, but will make an effort to start.

The circuit on Andy's page *should* work, but it does have problems (in theory anyway). It doesn't adhere to RS232 standards, but it circumvents the rules. It should work, but it might not. That's why I don't use that one either. The only way to find out is to try it and see. The MAX232 *does* adhere to RS232 specifications, and that's one of the reasons I prefer the circuit I build (which is, admittedly, pretty component-intense).

Basically, you'll need to build it just like on the page, but use a 10k resistor between the A & B ALDL pins to kick the '165 in to 8192 mode. With Craig's software, you'll need to provide the external 12V hookup - probably from a cig lighter adapter.

Any other questions, please feel free to email me.

Cheers,

Andrew

Forced_GTA

Thanks for the help. I already built a circuit I got from a completely different source (on a breadboard) with the RS232 chip I had, so I am going to test it out to see if it works. Out of curiousity, I am going to build the circuit with two transistors to see if it works also, and also build the other RS-232 schematic listed on andy's page (the first, less complicated one). Maybe I can help out everyone figure out what is usable exactly for thirdgens. It seems that our interface is a lot simpler than the LT1 one (which I assume you sell most of your cables for).

I still need to get a good 9-pin connector though, and can't test anything out until I get one. Tommorow I'll make another trip to the electronics store, while I'm at it i'll go scavange the $.50 PC boards again for 27256-1 chips or 128 K as well. You can email me @ cs8wbz@ucsd.edu.

This stuff is really important to me now, as I put on a supercharger but am having big fuel problems (running lean). Believe it or not, I am an Electrical Engineering student at UC San Diego. I just switched into the major and have only taken 2 electronic's classes, so most of this stuff is not too familiar to me.

Forced_GTA

I just got the cable working working. I picked up a 9-pin cable for $1, cut it and used that, then put a 10K resist from A to B ports and plugged one cable from the 2-trans circuit into the M port. I used power from the fusebox and a ground from the battery. Tommorow I am going to pick up a ciggarette lighter adapter so It will be a lot easier to plug in. Worked first time w/ craig's software! Total cost for me to build circuit was about $19. I have enough parts left over to build 2 more of the more complicated converterters using the MAX232, that's why it's so much. The max232 chip's are what cost me the most, at $8, and I ended up not using them. $6-10 would have been the cost if I didn't buy the parts to make 3 different interfaces. While I was at the electronics store I picked up 3 128K EPROMS for $.50 off of a controller card from 1989.. one is bound to work. I also have 3 more 256K EProms I picked of a 286 motherboard for $.50 too last week. I think I am going to order the chip burner soon and start burning some new proms.. i'm pretty excited!

So far total cost for me:

$25 for Cable/EPROMS/Misc Supplies
+ FREE 486 Color Laptop
+ FREE Power Inverter
+ FREE Craig's Software
--- $25!

This is the best bang for the buck stuff I have done to my car!

Now I get to figure out why my car feels slower than it did before I put 6 lbs of boost on it.

Thanks for the help Craig and Andrew!