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PostPosted: Mon Dec 31, 2012 1:33 pm 
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Location: drinking devil fuel
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Ah,
This reminds me of what I forgot to tell you over lunch :oops:

The adapter loom I have has the correct 3 way male to hook to the OEM Toyota loom. The connector is marked AMP but I have a feeling it's probably a clone looking at the overall quality. I think it probably came from Tractive. Might be worth a speculative call to see if they can offer any guidance for a one off project kind of thing

I've got a second extender loom somewhere that I need to dig out and check the connectors on


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PostPosted: Mon Dec 31, 2012 2:41 pm 
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I know the connectors are available as the 'adaptalink' box uses them. I just can't find a source for small quantity.

It's relatively easy to get the individual 'cable mounting' connectors, adapter looms are readily available on ebay.

The plan is to supply a short 'loom' with D plugs one end and sockets to fit the standard toyota loom the other.

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PostPosted: Mon Dec 31, 2012 7:37 pm 
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I can't believe the likes of Tractive go out and buy a metric sh**load of them though as the market is so small. A trawl of Alibaba might reveal a knock off supplier if your **sed supplies are high enough


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PostPosted: Thu Jan 03, 2013 12:34 am 
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Having abandoned the idea of using the original denso connector, I have re-jigged the inputs further into a more logical layout which also removed a lot of crossed tracks / via holes.
I applied more thought about my original decision to run the slave on the same 3.3V as the master. With the change to the knock chip (5V only) I had ended up with loads of level shifting circuitry between 5V and 3.3V when the only link between master & slave is 2 I2C lines. A bit of digging later revealed these pins on the master are 5V tolerant and open drain (output pulls down, external resistor pulls up) anyway so no problem driving these at 5V.

https://dl.dropbox.com/u/8316230/ecu/ECU_issA.pdf

https://dl.dropbox.com/u/8316230/ecu/EC ... layers.pdf

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I'm now happy enough with the design to go for a prototype batch. It will probably be about 6-10 boards as the cost isn't much greater than just 1. This gives me a couple for my cars, one for the bench plus a few for others to test when the time comes.

The cad system generates a 'drill file' (CNC file) which contains all the hole positions & sizes for the drilling machine plus 'gerber files' (photoplot files) which are used to generate the photographs for the 4 layers - Top copper, Bottom copper, solder resist (the dark green paint which covers all but solder pads), component ident (silk screen showing component locations)
These files will be emailed over to the PCB manufacturing company I use (in Essex) and in about 3-4 weeks I'll get the blank boards back.

Still on target to have one running an engine by the end of March, work permitting.

For anyone interested in the manufacturing process, this is the best I found on youtube.

http://www.youtube.com/watch?v=XKAeSjC-TDA

http://www.eurocircuits.com/index.php/p ... king-a-pcb

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PostPosted: Thu Jan 03, 2013 3:05 am 
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How about a jumpered ground link out to one of the case fixing screws. That way you have an option to ground the case easily if the need arises


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PostPosted: Thu Jan 03, 2013 2:32 pm 
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I was thinking of it, but dismissed on the basis the case will be screwed to body earth, and the ECU connects to engine earth. Recipe for a nasty earth loop at best, or burnt out loom / PCB track in the event of a poor earth connection from battery to starter.

May be worth a resistor between case & earth though just to take away noise if it's left hanging in mid air.

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 Post subject: Re: Developing an ecu ?
PostPosted: Tue Jan 08, 2013 12:34 am 
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To be fair I didn't find the MS's that hard to sus out, electronically or not, but I can see that most people won't want the hassle. But that's why the 1K+ market exists. I've not read this whole thread but I'm in the middle of doing something similar myself (though not specifically for the 3S, and won't be up for sale as I'll be basing it on the MS3 processor board and MS CPU's and code aren't licensed for use on non-MS motherboards - they have a habit of getting litigious). Mine's for the new V8 project, I don't want all the bloody daughterboards and wiring mods required on the MS, or the dodgy grounding schemes, or the poor connectors, so I intend to take the bare MS3 board and sit it neatly onto my own which contains all the ins and outs (8 sequential spark and fuel!) that I could ever want, including full power control circuitry. I'll bookmark your thread and see how you get on.


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 Post subject: Re: Developing an ecu ?
PostPosted: Tue Jan 08, 2013 12:10 pm 
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I was considering doing a custom motherboard for the megasquirt but was worried about the commercial minefield, never mind the technical one, of having half the design under someone elses control. I hadn't realised they were busy suing people, makes me even more sure I did the right thing. A shame they don't put the energy into adding the final polish to their product to make it viable for the masses.

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 Post subject: Re: Developing an ecu ?
PostPosted: Tue Jan 08, 2013 12:18 pm 
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To be fair I think it was forced by the number of people ripping their design off and selling flakey versions on ebay, but it is something to avoid. The primary reason I thought I'd stick with the MS is that while I'm happy developing the embedded code it'll stretch out my car design even further (I'm designing the car from scratch too) and I need off the shelf parts where possible to keep some things under control.

Are you sticking to tuner-studio type standard comms or are you writing your own tuning front end too?


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 Post subject: Re: Developing an ecu ?
PostPosted: Tue Jan 08, 2013 1:47 pm 
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In the short term, i'm doing (have done) custom front end software for the PC and USB interface. Longer term, I'm looking to go canbus / OBD2 so may open the door to standard mapping software.

First hurdle is to get it running my car so I can start testing it as I travel round doing my other work. Aiming for end of March.

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 Post subject: Re: Developing an ecu ?
PostPosted: Wed Jan 16, 2013 3:27 pm 
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What's IC8? I take it they didn't have it in through hole part? ;)

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 Post subject: Re: Developing an ecu ?
PostPosted: Wed Jan 16, 2013 6:48 pm 
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IC8 is the knock sensor interface chip.

IC5 is a cheap I2C d-a chip for setting trigger threshold voltage.

Neither are available in through hole.

IC8 is gen 1 surface mount and even an old git like me can handle it.
IC5 is only 6 pin and not that fine pitch so I can still handle it.

Currently a break in activity while the blanks are manufactured and I do some paid work :)


It also now appears the original ECU connectors ARE readilly available, and I should have half a dozen in the next few weeks. I'm very p***d off :lol:
For now, I'll make adapter looms for the test ones. When / if they go into production I'll probably do a toyota version with original connectors, not a massive job just another £85 tooling cost.

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 Post subject: Re: Developing an ecu ?
PostPosted: Thu Jan 17, 2013 9:23 am 
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If and when you go to the stock connectors, what other mods will you need to do to run the ecu?
Wideband sensors etc..?? (or will that be selectable via software options??)

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 Post subject: Re: Developing an ecu ?
PostPosted: Thu Jan 17, 2013 11:49 am 
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Wideband will be selectable in software. Without wideband you will lose the 'weak on boost' safety feature. Otherwise, no mods required plug & playtime.

Hopefully it will also allow ditching of the AFM on a 185 and use the turbo pressure sensor instead, may need uprating to a 205 sensor for higher boost than standard.

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 Post subject: Re: Developing an ecu ?
PostPosted: Fri Jan 18, 2013 12:06 am 
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Location: Bournemouth
Car Model: ST205
Ohh, I see this ECU is for the ST185....
Will it do the ST205? (sorry, don't know much about the differences between the 2)
Knowing you, I'll guess it will do both :mrgreen:

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