building a harness

FreeEMS topics that aren't specific to hardware development or firmware development.
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Fred
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Re: building a harness

Post by Fred »

Hello and welcome, Nathan!

Sorry to be obtuse, but ask again end of next week and there will be more info on that subject :-)

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Re: building a harness

Post by Ronin7 »

Ahh, understood. That is good news.

Thanks,
Nathan
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Re: building a harness

Post by andg »

Peter: Everyone I talk to tries talking me out of it. It is incredible how much effort is involved plugging sensors into a breadboard. If I make it 20% of the way through I'll call it success. Thank you for sharing some experiences and gotchas. This is by far the biggest electronics engineering project I've taken on, but I'm just looking at it as a way to bond with my car.

Fred: I didn't mean to sound like I was rushing when I say that I may use Sean's PCB to get the car ranked, I was trying to explain how the big picture of the project seems to be coming together. I'm exclusively working on the harness first, and will move to building a Jaguar after getting it started once in my garage with Sean's PCB if he lets me. I can begin to tie in
Manualise your auto FTW :-)
hopefully after getting the thing started. That's why I call her 'car 25'.

Nathan: Have you read about the Jaguar board in this truck? Assembling the Jaguar pictures. It looks to me like the PCB is printed by a manufacturer and assembled by you or me. Here's the information on the Jaguar on github. There are big bold letters that say 'don't use this, it is being upgraded'. I'm pretty sure that is the reason that Fred originally informed me that I ought to hold off building one.

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{url: andrewgauger.com, skype: andrgaug, email: andg@andrewgauger.com, car: 25, fb: facebook.com/DonatoArrighi, github: andg.github.io, assets:https://s3.amazonaws.com/3400}
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Re: building a harness

Post by Fred »

Nope, that wasn't the reason! :-) Those warnings are a bit misleading and should likely be changed. Andy is working on the dev branch which is in a state of flux but is miles better than master branch by now.

BTW, what is the objective with the bread board thing? I don't understand the point of doing that.

Fred.
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sim
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Re: building a harness

Post by sim »

I can definitely back up the sentiments in this thread.

Building my own TA based board was really fun, both of the times
that I did it.

My first attempt worked, and ran the car. Like Peter, my analog
conditioners were a total rat's nest and proved to be
unmaintainable. Some still undiagnosed fault therein prompted me
to start from scratch and do the whole thing over after I lost my
MAP signal. It was pretty cool when the manifold was glowing
cherry red though.

The second iteration is much neater, and built with an eye
towards expansion and troubleshooting. It also pretty much fills
up a plastic shoebox in the passenger footwell. Passengers hate
that for some reason.

All that said, I had a great time building, and then rebuilding
my ECU. I learned a whole bunch in the process. It is still very
much a work in progress.

I fully intend to throw the works away yet again at some point in
the (hopefully) near future. When the time is right, I'd like to
replace it with a low serial number RavAGE board. I wouldn't
hesitate to run Andy's board either, he did a great job and it is
a proven design. I'm pretty sure the Jaguar board has been behind
the largest number of running cars, so far.

My homemade junk is very much a prototype, it was, however,
very satisfying to see it actually work.
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Re: building a harness

Post by andg »

Fred wrote: the bread board thing? I don't understand the point of doing that.
Sadly, it is just there to hold my wires in order while I keep working on harness. I might use jumpers to get to a board, I might not. Since I have PLANNED that far ahead I needed to do something.
sim wrote: Passengers hate that for some reason.
That would be a good fit for me, I don't like passengers. Thanks for chiming in. I'm thrilled how many folks running FreeEMS have pitched in with their personal experiences--a super big help for someone using a breadboard because they can't see over the hill they had to upshift to climb.

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{url: andrewgauger.com, skype: andrgaug, email: andg@andrewgauger.com, car: 25, fb: facebook.com/DonatoArrighi, github: andg.github.io, assets:https://s3.amazonaws.com/3400}
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Re: building a harness

Post by andg »

Peter:
You are my closest role model. In terms of geography you own the hardware nearest my current location, Portland. Additionally you have 2 daily drivers! My goal is exclusively daily driver related. I have a 65 mile daily commute from Woodburn, OR ( the `city` between Portland and Salem) to downtown Portland. For me reliability trumps performance. I want to challenge to DIY market with this perspective, but I feel you've already proven it with your winter/summer daily drivers that have been maintained since inception.
peter wrote:The worst part is when you have a problem it's fairly hard to track down
This was the second time I heard this exact revelation, first was on my alternate board, ga owners club, so I'm inclined to listen.

I've been reading your history (there's a lot of catching up to do) and noticed your posting style is pretty close to mine: peter's posts. I also noticed a hint of reckless abandon which is my specialty.

If it were possible, I'd like to consider getting to know you better, venturing out to see your setups, and getting some advice in the technique category. I want to build a board from components, dive deeper into electrical engineering, and get some user feedback. Any chance we can arrange for any of that?

AG

Code: Select all

{url: andrewgauger.com, skype: andrgaug, email: andg@andrewgauger.com, car: 25, fb: facebook.com/DonatoArrighi, github: andg.github.io, assets:https://s3.amazonaws.com/3400}
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Re: building a harness

Post by sim »

andg wrote: In terms of geography you own the hardware nearest my current location, Portland.
I don't know man, by my reckoning, the Snot Rocket is almost
five hundred miles closer to Portland than any place in Wyoming with a
name is.

But that's okay, he is way more bad-ass than I.
<@TekniQue> but in the end, it's code that makes a computer useful
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Re: building a harness

Post by Fred »

andg wrote:I also noticed a hint of reckless abandon which is my specialty.
ROFL! I noticed this too, and preceded to start begging him to be nicer to his cars, at which point he started sending me photographs of transfer cases split clean in half, cracked blocks, and other wanton destruction.

You'll be in good hands no matter which direction you choose to travel in. I rate both of these two clowns very highly indeed :-)

Fred.
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Re: building a harness

Post by Fred »

andg wrote:first was on my alternate board, ga owners club, so I'm inclined to listen.
Man, that guy is ULTRA conservative! He offers some good advice, but I'm going to hammer a few points:
Matt95GT wrote:2. Looking at the I/O of the hardware you intend to use... I do not see support for IAC, or even a fast-idle valve. Speaking from first-hand experience - it is difficult to get an engine to start/idle/warm up without it.
Firstly, he's blind, the IO of the HW that you intend to use has 11 FETs on it, You can do a LOT with 11 FETs, but a fast idle output is virtually for free, if that's all you need. A PWM idle output is pretty much for free (30mins behind a keyboard, 5 behind a soldering iron). If you need GM stepper idle, then that's going to take a tiny bit more code, and possibly some extra hardware.

Secondly, not having it meaning getting a car running is hard is total bullshit unless you're completely unaware of your engine's airflow requirements and utterly fail to use your brain and right foot in combination to push the pedal slightly and allow some air into the engine. It's true that many electronic engines virtually block all air flow by default, so if the throttle was closed on one of these, it'd never start. It doesn't take a mongo-db expert to work this out, though. IE, a mongo-db expert will have no trouble at all. Add a bleed valve to any nipple on the manifold and be happy.

I've never had a factory service manual for any of the engines I've toyed with. Yanks seem to think it's a requirement. I don't understand that, nor buying refurbished "axles" instead of just buying a brand new CV joint and installing it. You have two eyes and one brain, this is sufficient.

"Your application is a complex one" - only as complex as you make it. You're taking the right approach... get it running in the driveway, figure out trans control, drive it. IE, minimise the scope of failure and minimise the variables. Your engine is not complex to run, it's well known and simple. Your dash, I have no idea, that's your problem :-)

"but it will complicate troubleshooting" Peter was referring to hacked up DIY hardware. This guy is referring to the entire shooting match. I'll be bold and disagree outright here too: If you ever opened a MS tuning app, then you know you're confronted with 8390859485 (confusingly named) config parameters. By contrast FreeEMS has only a handful of (confusingly named) config parameters, so you won't get lost in the "what's this for" loop which can and does burn hours of a msers time. Logging is pretty detailed and useful for debugging, because it's a priority to have transparency over what the ECU is doing. The simplicity is a huge benefit for getting things setup/working at all. It's a huge down side if you need XYZ feature. But you don't, you need only a handful of features.

Fred.
DIYEFI.org - where Open Source means Open Source, and Free means Freedom
FreeEMS.org - the open source engine management system
FreeEMS dev diary and its comments thread and my turbo truck!
n00bs, do NOT PM or email tech questions! Use the forum!
The ever growing list of FreeEMS success stories!
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