Connector considerations

[GartnerProspect]

I was under the impression that making a counterfeit board was the problem. Which is understandable, if party A spends the time doing a layout of a board and then Party B completely copies that whole design to make a few bucks. That's pretty much flagrant violation of copyright.

Building a board that is completely different from a B&G design but used a MS processor was fair game in my understanding. The B&G code offers no limitations on distribution or use aside from the fact that code derivatives required the header.

And if that's not that case then I stand corrected.

[Tony]

Well my impression is the MS1 MS2 processor and the associated firmware and software is copyrighted.

[jbelanger]

Building a board that is completely different from a B&G design but used a MS processor was fair game in my understanding. The B&G code offers no limitations on distribution or use aside from the fact that code derivatives required the header.

That's not true. The firmware has to be run on B&G hardware only unless you have a license. The only licensed hardware I'm aware of is the Spectre eMS-Pro.

Jean

[GartnerProspect]

Building a board that is completely different from a B&G design but used a MS processor was fair game in my understanding. The B&G code offers no limitations on distribution or use aside from the fact that code derivatives required the header.

That's not true. The firmware has to be run on B&G hardware only unless you have a license. The only licensed hardware I'm aware of is the Spectre eMS-Pro.

Jean

I've looked high and low and can't find anything that says that in the code or any megasquirt documentation. And believe me I've looked.

I can see why they would try to limit the hardware that their code can run on but I'm just not sure they can.

[Fred]

Wow!!

Awesome discussions guys, even if it did go a bit OT at the end.

I Believe Gartners last post is on the legal money, but I don't care either way. I want nothing to do with copying it.

For the record, it has been said many times before that if an individual wants to make their own board up for their own use, they should just ask, and permission will likely be granted :

No one is allowed to copy the hardware without permisiion, even for personal use. For personal use, we generally grant permissiion, with restrictions (to prevent someone from taking a personal use permission and twisting it to allow commercial use).

This thread is long gone... I have a full copy of it in my email though.

Cam : Thanks for outlining what I want to achieve. Physical separation of high and low power stuff. The main reason for putting stuff on both ends is the lack of room on one end of a suitably compact enclosure. I would be OK with both in and out stuff on one end, but it will need separate grounds and powers as discussed elsewhere. My irrational fear of noise is not what made me say both ends, just lack of space without going to an enclosure that is too high. Don't forget, we need around 100 pins of lowish current, and at least 2 high current ones. preferrably 4 or 5.

To reiterate my thoughts here :

1 x 25m outputs
1 x 25f outputs
1 x hd15m inputs
1 x hd15f inputs
1 x 15m inputs

we also need room for the serial db9 and/or usb connector(s) and power connector.

for power, amphenol style 3 pin is a likely candidate for the INITIAL and budget root : 2 x ground 1x power, and through the db stuff, a further 2x parallel power feeds for the cpu, and 1 battery voltage reference with INDEPENDENT filtering.

http://www.diyefi.org/forum/viewtopic.php?p=85#p85

Also : ROFL at Flacids suggestion. If we can fit the adapt card and and adapter in there with a v3, all the better way to get up and running fast :-)

[AbeFM]

http://www.glenair.com/micro-d/

We use these all the time at work. Ok, so they aren't cheap, but lots of companies make them, don't get them from glenair. But they handle great current, and the 3 row micro D has 57 pins and is like 1" wide, not very thick, and doesn't take up huge space on the board.

'Course, I still think it's a bit hard to source for a first spin, but it IS worth keeping in mind, they are very rugged, good with weather, etc. There are plenty of MILspec parts for them.

[Fred]

http://www.dataspares.com/

pmed to me by anon...

[GartnerProspect]

Well, I have no interest in copying them either to be fair.

And that snippet was regarding copying the existing layout from everything I could gather. Which again I have no interest in doing whatsoever. Since IMO the existing hardware isn't worth copying.

However, I do intend on using a Motorola 68HC908, with MSExtra firmware for initial testing of MY hardware. Because it's proven, simple, doesn't require a lot of ancillary hardware making the daughterboard simple as well. I'm going to leave ample realestate on the board to incorporate a number of different things, and make availible enough I/O that the baby jesus may very well cry over it. The idea? Just because the 68HC908 doesn't have the nuts for 8 cylinder sequential/cop doesn't mean the hardware should be neutered. That way when youre CPU has working code, all I need is a daughterboard to plug into the main board.

The more I look at the options the more and more I just feel like sticking with the DB series plugs. And Based out of simple fact that the existing cases make it easy, I'm going towards double ended boards as well. DB-37 on each end maybe.

What is the thought on the current carrying of the DB-xx connectors. I've seen single pin ratings as high as 7.5amp. Though it seems in the case of the DB-37 you can cut that to 1/3rd if you load up all the pins. I guess in real world that shouldn't be an issue and running single injectors per pin seems perfectly reasonable.

[FlappySocks]

I am happy with D connectors, although I have encountered some people that have grumbled about them...calling them printer ports, and such like. If they are good enough for Thatcham approved security devices then it's good enough for an ECU. They can be a pain to solder though.

I use 3 pins per output on my spark driver boards.

[jharvey]

I had some thoughts about connectors, I haven't read the thread yet, but I'll post my thoughts anyhow.

I don't like the familiar DB series connectors, or AMP connectors, and I'm not sure I like a connector. First off, why do you need a connector? Mostly for easy removal from the vehicle, but how often do you need to remove the ECU after installation?

The connector limits your design. The DB connectors aren't water resistant, but the amp connector requires thru holes to mount, increasing the cost to mfg. Both require multiple lines for ground and power due to currents that would exceed a single pin capabilities. Especially with the injector and the VR circuits, every connector has the chance of becoming a tank circuit, if a real good connection isn't made. Tank circuits are know for making very high voltage which can cause quite a bit of damage. Minimizing the connectors would help prevent issues that many non-radio folks won't understand.

Check the description found here http://en.wikipedia.org/wiki/LC_circuit. Not free, but also good from circuit cellar #191 June 2006 on pg 50 an article titled Stepper Failure by Ed Nisley. It does a great job explaining the importance of a good connection when you have an inductive load.

Perhaps a better solution is to have wire lengths that solder directly to the PCB and after 12" or so use a harness connector. Those that want water proof, can glop the entire PCB (or put int in a box, and clop just the wires), but those that don't can simply leave it in a box. That way you can run fat wires directly where needed, and little signal wires can keep their distance.

If I chose a connector it would certainly be a double row connector that allowed for sandwiching the PCB between the rows removing the need for thru holes. It would also be water resistant, and hopefully would have different pin sizes for power and signal wires.

Any how just some connection considerations.