FREEEMS hardware schematic and PCB

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Fred
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Re: FREEEMS hardware schematic and PCB

Post by Fred »

I have some comments on the comments :

The TA card is NOT designed to take power in through the 50 pin connectors, that is to feed power OUT to low draw accessories. It is always the case that a second two wires for power are required with the TA card.

With respect to 2 vs 4 layer boards. Freescale actively recommend/require a 4 layer board is used and provide a reference pad layout for it in the documentation. I would say that is one of the only reasons to not just buy one, ie, if the one you are making is 4 layer and less susceptible to noise. Of course, cost is another if you have plenty of time on your hands :-) Yet another is flexibility, perhaps a one piece dedicated dev setup rather than a bunch of aux boards and a TA card.

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Re: FREEEMS hardware schematic and PCB

Post by lekker »

jharvey,

Thank you for the comments on the power concern. You have the credit.
I think we are not hurry to get the CPU board farbricated yet, since the main board is not done yet.
Without the main board we hardly can do anything on it.
Let me know beside the power issue whatelse you can think of that we need to change on the FreeEMS TA card.

AD 2009, is a play toy for me. It is the Altium Designer 2009. I am collecting tools that I can use to convert it to other programs, e.g., Eagle 4.5, or Protel99, edgeCAD, KiCAD.

The bare CPU board will be around $10 each, and I will also have a populated PCBA.

-L
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Re: FREEEMS hardware schematic and PCB

Post by jharvey »

I'm really not familiar with the TA pinout all that much. I'm glad I was able to raise the general idea.

I seem to recall KICAD can import gerber files to a specified layer. That may make for the easiest translation, if we are looking to get the design files into a free package. For now it's probably best to keep one copy. Perhaps I should inquire about gerbers just to see if it's possible to translate.
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Re: FREEEMS hardware schematic and PCB

Post by jharvey »

Seems like it's nearly time for me to poke about this again. Once I see posted firmware, I'm going to start looking a bit harder at the obtaining the brain. What's the status of this board? I have a re-flow toaster oven, and solder paste, so SMT assembly isn't a bit deal for me.
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Re: FREEEMS hardware schematic and PCB

Post by Fred »

When I do post the firmware, it won't help you at all. I've implemented just the minimum to get the Volvo running and prove the basic fundamental speed density and infrastructure code. Mission accomplished ;-) The code still needs some major arch changes and I'm hoping EssEss will be helping me design that as I feel like a noob in his presence ;-) After those changes we'll have some finalised stuff to design boards around. I expect around 6 months from now we'll have something close to generally useful, but don't try to hold me to that.

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Re: FREEEMS hardware schematic and PCB

Post by sry_not4sale »

Fred, am I right in saying we really need to get some more engines running with the code before committing to a hardware stuff?

Obviously the code still needs work, but more test engines would be a good thing right? Like - in the next month?
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Fred
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Re: FREEEMS hardware schematic and PCB

Post by Fred »

To be honest, I don't think we do need that at all. I'm fully aware of the current state of the code, both yours and mine and know what needs to be achieved and 99% of it can be done on the bench. If anyone *wants* to use it, by all means. I can't promise it will run as well as the Volvo has, that has come as a surprise even to me. So in summary, no need, but more testers, bench or real, welcome as always :-)

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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jharvey
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Re: FREEEMS hardware schematic and PCB

Post by jharvey »

Great, so this version of the brain board is a go right? Last I recall, there weren't any concerns about moving much around for pins. I seem to recall the only concerns were relative to the power supply, which I believe were addressed. So no more issues with this board right?

I was hoping lekker would chime in about getting a PCB spun, ect.
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Re: FREEEMS hardware schematic and PCB

Post by tpsretard »

Just a thought..

The code is far from production.
The hardware is even farther. for the people that will be contributing to this. would it note make sence to do up an eval board.

Using something like Pad2Pad, erexpressPCB or any of them, do up a devel board, with say 6 points for VNP5N07 and 6 coil drivers. (or logic, i dunno what you using) like the bip373, dos not run overly hot, and i am yet to kill it.. (yes i have tryed) some other basic curcuits like air temp, water temp. map and a few general input and output circuits..

Use the same dam DB37 connector the megasquirt uses if you want. You can even take a page out of the DIYPNP boards where you have to jump most things with wire..

And then on some point of the board put the header for the TA card..

This would be a cheep enough option and will allow better testing on a real engine than anything else..
Then as code develops and hardware bugs are found, like noisy inputs, no one person has sheld out a crap load of money on a board that now needs redesigning...

Shit, i am sure with my VERY limited use of Pad2Pad i could even toss something up, using borrowed circuits, from megasquirt on others. How different are things like inputs etc anyway..

How ever i am a novice at this part of the world, so
take my suggestions with a shot of tequila :)
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EssEss
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Re: FREEEMS hardware schematic and PCB

Post by EssEss »

I thought jared's board was essentially that ? ... but with a lot more thought since he had the time while waiting for s/w.
The current path looks sound to me :indiff: I would never expect the first spin of this to be the last either, just load what is important to your application. :P
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