DIY Autotap cable

[youngcamarokid]

Yes, I used the search function first, and did not find what I was looking for.

I would like to make a cable for Autotap, because I don't want to spend $290 for the cable.

I have all the tools necessary, I can use microcontrollers, and yes I know that there is probably a translation box with a MCU that runs firmware on it.

I know it's ambitious, but I need to know if anybody out there knows how to do it. If not, please tell me that you can't, and I'll look elsewhere.

Thanks,
Kyle

[OneQuickV6]

No offense, but if you know how to use micro-controllers or program them or anything, then you are more than likely an EE major...being one also, I would never want my hard work later on in life to be ripped off by someone because they don't wanna pay for it...At my school, in EE, we have ethics classes too. It would suck to oput so much time and effort into something to HELP OTHERS, and then they just rip you off so you don't make money off of it. Hope you aren't looking into your P.E. this could definitely cause you to lose it.

[youngcamarokid]

I'm 15 years old. I'm just smart for my age, and have no life outside of electronics.

I know it's totally ripping them off, but either way, they're not getting my money.

[Magnus]

You need an RS232 to VPW converter to talk to the class 2 bus for PCM communication.

To recreate an autotap cable, you will need their schematics along with their firmware. You will need a cable to look off of and take apart so find a friend that doesn't mind their autotap cable being hacked up.

Then you're going to need the firmware, so e-mail them for that.

Oh yea, you'll also need their permission.. e-mail them for that as well.

You'd be better off just making your own converter using a MOT chip.

[youngcamarokid]

Alright Magnus, thanks, that's what I figured. I had a feeling they have their firmware on a chip, it only makes sense and all.

So what other options do I have? As stated previously, I have all the tools I would need.

I just want to be able to view real time data and log data as well as graphs etc.

[Magnus]

to view real time data you have to poll the PCM to send you that data... so you need to know the VPW protocol. The protocol is documented in the pcm forum, http://pcm.dxsoftware.com/forum/

but you need an RS232 to VPW converter. If you want to build your own, read some of the threads on there... there are several chips available for simple monitoring...

now if you want to actually program the pcm's, the chips capable of such are not many.

Your options are...
spend hours and hours designing your own cable.
spend hours and hours writing the polling software.

buy a pre-made cable and spend hours and hours writing software.

try using pauls software and modify it for yoru own made cable or one you bought.

get a job for a week and buy the cable.

[67-03 RIP]

Scan Tool web page has a ton of info on building a converter with the elm chip - including schematics and chip info. Thought it said it was compatible with autotap, but don't quote me on that.


Ron

You can buy their kit for $65-8 roughly and also get free software that you can modify (again I think). This wouldn't be taking anybody elses work and could be some fun. Also

[ March 28, 2003: Message edited by: 67-03 RIP ]Elm Electronics

[ March 28, 2003: Message edited by: 67-03 RIP ]</p>

[youngcamarokid]

Alright, thanks guys, I'll keep looking. I don't want to modify the parameters, just view them.

Magnus - not to be a smart *** but I do have a job. 1) All my money is going towards my car, I owe $4100 on it. 2) If I scraped up the money, my parents wouldn't let me get Autotap anyway *sigh*

:(

[AZ3.8Camaro]

<blockquote>quote:</font><hr>Originally posted by youngcamarokid:
I'm 15 years old. I'm just smart for my age, and have no life outside of electronics.

I know it's totally ripping them off, but either way, they're not getting my money.<hr></blockquote>

They let 15 year olds drive in WA?? Sweet! :D

[youngcamarokid]

<blockquote>quote:</font><hr>Originally posted by AZ3.8Camaro:


They let 15 year olds drive in WA?? Sweet! :D <hr></blockquote>

Yeah I wish!

Unfortunately, no, they don't, I just am patiently awaiting the day that i can get my license :D

[Magnus]

Hey I'm not trying to come down on you.. If you're in this to learn then it's a great way.. but if you're in it just to save money, well then it may be better to just find a part time job.

This VPW stuff can get VERY in depth and very time consuming.

[youngcamarokid]

It's a little bit of both, and like I said, I already have a job but my parents won't let me spend the money and it's all going towards paying off my car anyway.

It's okay that it can get very in depth, I'm used to that already with my other interface projects that I've done. I'm not afraid to work with electronics :D

Where I have trouble is the code aspect. That is, the code for the PC. I can't write code at all, only MCU code.

Do you suggest any alternatives that I could use? I've looked at that PCM website...don't remember what it is...but I didn't find any threads that are helpful.