Connector considerations

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AbeFM
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Re: Connector considerations

Post by AbeFM »

Ah,you mean similar to the AEM board shown earlier?

If that were the case, I would think a vertical board might work. I dunno.

At any rate, I think with DB's your free to "boomslang" or make an adapter, though I admit something which clasps and auto alligns might be better if we knew we were to use a breakout board.

Then again, since we're likely (very likely) to have connectors on each card, any breakout board would likely have pigtails to get signals to the additional boards.

Image

I think it would start off using DB's, and some final instal would have an adapter board as pictured.
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jharvey
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Re: Connector considerations

Post by jharvey »

PCB mounted 90 degree CPC connector $12 for qty 1.

http://octopart.com/info/Tyco+Electronics/1-796375-1

[EDIT]

This is probably the best place I've found to browse the options available for CPC connectors.

http://catalog.tycoelectronics.com/cata ... ML=10000-C

I see 90 cable connectors for harness connections, as well as plugs for protecting unused connectors. Might come in handy for those that plan for a turbo, but want to get it going now. It would allow additional sensors to be planned for, and implemented later.
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Re: Connector considerations

Post by jbelanger »

But it's only a 9-position connector which is not much use in this case.

Abe, you forgot the cooler board above the CPU board in your picture :)
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jharvey
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Re: Connector considerations

Post by jharvey »

8InchesFlacid wrote:Then again, since we're likely (very likely) to have connectors on each card, any breakout board would likely have pigtails to get signals to the additional boards.
What you draw is very similar to a back plane. Much like the PCI card slots are part of the the PCI back plane in your PC. However, I'm not sure we really want a back plane theory. I kind of like the theory of driving the data down the center of the stack with power lines dedicated near the out sides of the PCB. Helps seperate the power from the data. A backplane approach forces them near each other.

About the beer storage, I'm not sure I like it. That's going to be way too hot. Perhaps if the expansion card includes Peltier junctions to keep the CPU temp low, then it could work.

The below is OT and again from NZ, but shows my point it's very important to keep the beer cold.

http://www.asciimation.co.nz/beer/
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AbeFM
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Re: Connector considerations

Post by AbeFM »

I just wasn't going to redraw it to take out the empty space. Sheesh!

I was just going to keep using stacked connectors like the computer board, not shown. A actual backplane would just be ANOTHER expensive piece to add in. More connectors, more routing...

remember, small/fast/cheap.
oughtsix
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Re: Connector considerations

Post by oughtsix »

Image

To me the solution seems VERY simple. The connector board should support a DB37 with pinouts compatible with Megasquirt/JimStim, an Amphenol connector and a screw terminal strip all on the same board. If someone doesn't want a particular connector on the board they can take a saw and cut off that portion of the connector board to save space!!!!!

Assuming that the Adapt9S12XDP512M2 is the dark blue board in the center and the rectangles are 50pin connectors in my opinion this is the perfect design for the connector board. Flexible and cheap!!!!! Put 50pin male connectors between each external connector and the CPU board with each adjacent pin jumpered with a circuit board trace. If you dont want that pin on that connector hot then cut the trace. If you decide later that you actually wanted that pin hot put a standard jumper on the pins like a computer motherboard. If you need pin 17 to go to pin 7 on the connector... cut the traces and use a wire jumper like the ones that come with Jimstims. Or use a wirewrap to tie two pins together more permanently.

What to do with the 4th edge of the board???? How about a Ford ECU connector??? Don't want a Ford ECU connector? Don't buy one and don't solder it on!!!!

I added an extra 50pin connector because I assume there is going to be an interface board with the high current drivers sandwiched between the Adapt9S12XDP512M2 and the connector board. This extra bus would be used to pass the signals from the interface board to the connector board. These are the signals that will most likely be routed to the external connectors!

Personally I see a sandwich of the Adapt9S12XDP512M2 board, a wideband O2 interface board and the High Z injector and ignition driver board and the connector board. Yes that is a stack of four boards!

From what I can tell from the MegaSquirt site MEgaSquirt III is all but dead. Honestly I believe from what I have seen this effort is what MSIII should have been to start with!!! Cheap to get started, flexible and expandable!!! My vision is I buy the Adapt9S12XDP512M2 board and the interface board (Or build the interface board on one of the prototype boards available). And do a group buy of the Connector board. Then I solder in the DB37 to test things out with the JimStim. Then I pull my MSII and plug in this board and test things out. Then I pull this board out of my car and I drive to work with the MSII. "I" think that this arrangement would cater to most MSII owners, especially the DIYer's that would make this project a success!

Just my 2 cents.
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Re: Connector considerations

Post by oughtsix »

Hmmmm..... Could we leave room on the connector board for the power relays and fuses so I can use the terminal strip as my only interface without having a MegaSquirt relayboard? After cutting off the connectors I don't need I would almost have something more convenient than a microsquirt!
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AbeFM
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Re: Connector considerations

Post by AbeFM »

I do like the idea of supporting a DB-37, yes, jimstim and the rest support it, and it's still a very viable, low cost, readily available connector. The downside is the MS pinout is beyond salvation. it would be very difficult to make something both useful and compatible (but not impossible), so that the "extra" sensors and outputs used the extra ground pins. I'm still not against a power connector and a signal connector.

The multi connector board isn't a bad idea.

Really, my own personal vision is we get something out - something solid and simple - ASAP. Hardware is NOT irreplaceable, and by using stacking, we can replace one section or another in hardware without building a whole new box every time. I like the concept of hacking off what you don't need. :-)

But for now, I'm still an advocate of a DB37 and a DB25 (or some similar combination of parts), and see 4 cars running on this. When it's working, and our horrible misconceptions and oversights become apparent, then we design something more akin to what you've got.

What I'm saying is the first release should be an alpha - in hardware as well as software. Let's stop worrying so much, get something working, then design it. And in the meantime, all this discussion is very useful, and means when the kinks are worked out, this sort of thing will be ready to go. (The nice part is it allows tweaking of the pin assignment without worrying about it's impact on the connector and other boards)
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Re: Connector considerations

Post by jharvey »

I still think the best I've heard is making a connector board specific to the application. If you have an OEM harness connector, make a connector board with that connector, and you don't have to cut anthing OEM. Put a DB37 on it for testing with the JIM stim, ect. I'd guess that eventually someone will consider MS as thier OEM and make a connector board for it, however, that's not really a good conenctor setup, so you really would want to make a new connector.
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Re: Connector considerations

Post by Fred »

Abe, I agree to a point, but I'm a bit scared that one of several things will happen :

1) we knock out a board now and it sucks so we fix all the things wrong with it and leave those with the first board out of pocket.
2) we knock out a board now and it sucks but too many people are upset about change so we stick with it and end up in a mess. (this is worse)

So, as I see it, we need some basic decisions made up front. I don't mind if the first board is rough-as-guts but I do want it to be sensibly designed at a connection and configuration level. My first attempt to run a car will be on bread board shoe horned into an oem case. I would recommend others that want to help dury rig something like this too.
jharvey wrote:I still think the best I've heard is making a connector board specific to the application.
I'm starting to come around to this idea myself. It would mean a very modular and generic system that could be used with all sorts.

oughtsix, firstly, welcome along :-)

secondly, "ms3 all but dead" where did you read this? Can you put a link in the ms3 progress thread in non-free?

lastly, the whole point of this project is to allow total freedom in hardware such that it grows with time and doesn't stagnate. what this means is that it should be straight forward for you to make something like the above when the time comes.

Thanks to all three of you for your input!

Fred.
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