Letting go of the "MegaSquirt mindset" (hardware)

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davebmw
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Re: Letting go of the "MegaSquirt mindset" (hardware)

Post by davebmw »

GrowlingandBiffo wrote:Eurocard is a standard format, not a size per sec.

http://en.wikipedia.org/wiki/Eurocard_%28PCB%29

You should always use lead free products as lead is banned and for very good reasons...
Apologies 100 x 160 is a eurocard size it is by far the most commonly used size for hobbyists that get PCB's made for them by the likes of PCB pool or similar PCB houses.

Lead solder is not "banned" it is being very slowly Phased out across most sectors, but the military products we build have a strictly non lead free policy.

The majority of component suppliers have switched over to ROHS compliant product purely because the one product is usually suitable for both lead and lead free processes.

It is widely accepted that lead free is the way to go as far as the environmental stance, but from a manufacturing and consumer aspect, lead free is an absolute nightmare in terms of long term reliability.
The noxious chemicals produced because of the increase in the quantity of the agressive flux required to make a decent fillet, is significantly more harmful to operative and environment than the trace amounts of lead that vapourise during processing of good old 60/40 Pb.

There are NO plans in the military sector to phase over to lead free the medical sector have concessions on vital pieces of equipent like ECG and dialysis machines.
The electronics test equipment manufacturers have boycotted Pb free altogether!
On the other hand end consumer goods like mobile and DECT phones, PC's and perhipherals, TV, AV equipment were some of the first to drift over as these product inevitably end up not being recycled but end up in landfills.

We in the UK have no government directives or EC driectives that say we must move over to lead free within any time frame.
Our factory has leadfree product and it only constitutes 5% of our total throughput, there just isn't that much of a call for it outside of mainstream disposable products.
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Fred
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Re: Letting go of the "MegaSquirt mindset" (hardware)

Post by Fred »

davebmw wrote:On the other hand end consumer goods like mobile and DECT phones, PC's and perhipherals, TV, AV equipment were some of the first to drift over as these product inevitably end up not being recycled but end up in landfills.
Failure rates have gone up there too, and so has the attitude that stuff *should* fail and thus be replaced not fixed. My girls fathers business is suffering from the latter a bit more than growing from the former though.

Lead free sucks, no doubt about it. I brought 60 40 with me from NZ and haven't seen it at maplins so imported some more from NZ. It seems since I left it's getting hard to buy the good stuff at home too :-( I have quite a good sized supply though, and the farnells etc still carry it...
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davebmw
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Re: Letting go of the "MegaSquirt mindset" (hardware)

Post by davebmw »

Our suppliers have a ready supply of the stuff if anyone has difficulty getting hold of it let me know by PM.
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Re: Letting go of the "MegaSquirt mindset" (hardware)

Post by Brian »

Regarding the earlier discussion of possible variations of PCB's that may get designed, I think that could be a good thing. Some people may not want or need the space for two VR ccts when they have a hall sensor on a crank wheel, or might want the inj drivers on board, or not, etc. Rather than having one PCB attempt to cater for as many engines as possible, engine specific PCB's could evolve, or PCB's with a specific feature set that cater for similar engine types. The common thread between the different PCB's could be one big schematic containing all the possible components/features/building blocks from which the required blocks could be taken to build the PCB variants. PCB's are relatively cheap, so having a few variants based on the common schematic according to the engine you want to fit it to makes sense to me. The PCB could be a "standard layout" to an extent also, once the chip is in place with it's support circuits and power supply and the standard ADC inputs are in place, then there is no need to reinvent the wheel for each variant.
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Re: Letting go of the "MegaSquirt mindset" (hardware)

Post by Fred »

Absolutely :-)

I do think we need an LCD variant first though = Lowest Common Denominator

That will allow most people to get involved without having to design a new board and increase adoption of the system.
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Re: Letting go of the "MegaSquirt mindset" (hardware)

Post by Brian »

I agree, LCD first. KIS. How do you envisage the PCB becoming available to people who want one, will someone design a PCB, and post the gerber files? Then anyone could get their own PCB made, or, someone gets a number of PCB's made and offers them for sale. After setup and tooling fees, the more PCB's made the cheaper it gets. I am asking to get an idea of what will be happening in the future.
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Re: Letting go of the "MegaSquirt mindset" (hardware)

Post by Fred »

Brian wrote:I agree, LCD first. KIS. How do you envisage the PCB becoming available to people who want one, will someone design a PCB, and post the gerber files? Then anyone could get their own PCB made, or, someone gets a number of PCB's made and offers them for sale. After setup and tooling fees, the more PCB's made the cheaper it gets. I am asking to get an idea of what will be happening in the future.
I 100% want one design at least to be available in full gerber/schem/pcb format so that people CAN print their own or have their own printed (think places like South America etc with harsh as all hell import laws/fees). I suspect that once we have a design that maybe 10 people or more are happy with we can get a small "bulk" buy happening and get a small batch made for testing and further development (maybe 100 boards and sell 9 each at cost for others to play with?). At some point someone will start manufacturing things and selling them, but I always want "home brew" to be an option for people so setting the stage with an open hardware design from the start is a good way to go IMO.

From my personal point of view, if worst came to worst I'd design my own mediocre setup and home print it with etchant :-) The code is key here and it's being worked on daily. By someone else at the moment too, not me! :-)

It's great that Jared has stepped up and started designing a basic board for us. I hadn't considered that it might take a long time, but I'm glad he's started now that I can see it dragging along much like the code so it's really good that he pushed for starting to do the work early.

It's only a matter of time now :-)

Fred.
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Re: Letting go of the "MegaSquirt mindset" (hardware)

Post by jharvey »

Hmmm so the VR might be a seperate board, that can be put in the ECU cavity, or not. Damn, I already drew the symbol. Now what am I going to do with it ;)

I'll probably make a freeEMS_VR_Module.sch for such a symbol to reside in, and add a couple points on the rpm input schematic for this to attach to. That way you can add VR as a seperate board, and you can add it if you need it, also if you need 2 VR's you can add one to each hall input schematic.

I think both VR and hall should be opto-isolated, any recommended parts for this? I've used the 4n26 (or equivilatn) before. They work well for most things. Thoughts?

I see KICAD can PDF, but when I do, it comes out 90 degrees off and off the edge of the page. Anyone know how to get this to print right? I'm played with several settings. I think I can get it to come out corccrectly as a post script, then I can use GSView to make sure it finishes the final step correctly. I'm still playing with it.

The PCB is going slow mostly because I only get 1/2hr here and there, wich is conbined with late hours, so most of it's starting and stopping. Slow and steady, then when I get it, it will be fast and burn.
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Re: Letting go of the "MegaSquirt mindset" (hardware)

Post by Fred »

What we want is a basic one box solution that with sufficient external ignitors can run an engine with no other external modules. Hence VR should be on board. If person X Y or Z doesn't want it there he can bridge the chip and build a module to buffer it remotely.

Why do you want to opto isolate a two preconditioned signals? Does it provide some noise immunity? What is the latency of such units? The voltage and ground isolation simply isn't required. I guess having an isolated ground could be nice though. Is that why you want it? I have a bunch of those here anyway, so it's an option for sure.

Does KiCad allow you to plonk components on top of each other? For the VR chip it would be nice if both through hole and SMD footprints were there in the same spot so you can choose the option that suits you. I'm not sure if that will work size/dimension wise, but it might. Keep it flexible. The SMD LM1815 is a lot cheaper.

We are SO far off topic in this thread... I'll have to have a thoughtful clean up and split off into another thread.

Fred.
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Re: Letting go of the "MegaSquirt mindset" (hardware)

Post by comrade904 »

I don't know how into dev you guys are, but I think you are letting go of the wrong parts and keeping the wrong parts of the MS mindset.

I agree that increasing system adoption should be priority 1, and with that in mind I think the system HAS to be universal. Instead, of aiming for a market that has a particular car, which will already be supported by competitors offering a universal solution, aim for the entire market by being universal.

The problem, is that a universal system is likely to be more expensive than a non-uni system. However, I believe that by making the system modular, with schematics avail and the open source community with is surprisingly intelligent.

Here is my idea:
one main board (the ecu, and communication port)
one timing wheel decoder board (that can be made or modified for universality)
1-12 injector boards
1-12 coil boards

The programmed main board get the timing information then outputs to another board that could be either injector or coil.

but make each board as cheap as possible or even make it possible to build some of the boards(home etching, and assembly).

So basicaly make the system small cheap and simple (universal) and gain sequential injection and COP by scaling system to meet your needs.

I'm new so go easy on me. but I wanted to get 4 MSv1 and link them together, but B&G hasn't been as nice to me so you guys get my idea instead. (call it multisquirt that should piss them off)

make your profit by selling home etching kits ;-)
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