Letting go of the "MegaSquirt mindset" (hardware)

[Fred]

To quote myself from the firmware version of this thread :

There have been quite a few instances of people thinking in the "ms way". While this isn't a bad way to think, I think it limits us a bit. I've been proven to do this myself, and consequently I've been making a conscious effort to think outside the box and really consider what is missing and what is there.

Firstly, ms1 and ms2 do a great job in almost any circumstances. Where they are lacking is in IO. COP + Sequential + lots of accessories and data logging.

And this, modified slightly for this thread :

Another area that I don't like is the complexity of configuration. This exists because of the attitude present that says "we must support all cars ever made", and "we must do it on a single board"

We need to remember why we are here, and that is, we need a sequential COP solution that is the same price as an MS2/v3 setup.

To this end, we really need to try hard to keep whatever INITIAL design we come up with accessible to everyone. More complex and better designs with nice connectors etc will definitely come later if we proceed correctly at first. If we get lofty with our dreams for a first board, we will rule out low budget types, and end up creating something that is more expensive than it needs to be in a minimalistic form.

We should be aiming for the parts used to be available world wide (even if this means crappy connectors by default)
We should be aiming for the parts used to be cheapish.
We should be aiming for the design to be simple and comprehensible for simple minded folks like myself :-)
We should be aiming for the design to be adaptable to future needs.

This is all for the INITIAL design. None of this is a limitation for what comes in the future. Already someone I know is planning a hand soldered full SMD board design. Though that would be difficult to build, MAN would it be fun! :-) That is great, BUT, for now, KISS :-)

http://www.diyefi.org/forum/viewtopic.php?f=8&t=27

I think a good initial goal is this :

2x 2 layer through hole boards
Places for as many IO conditioners as possible
Good power supply topology
All inputs protected properly so that the user can't kill their cpu.
All outputs protected as much as practically possible, possibly by optional component selection.

In that way, a basic user with a 4 cylinder could get 2 boards for maybe 30us each printed, buy the adapt card, the power supply stuff, the input conditioning stuff, 5 fets (4x injectors, 1x fuel pump), 4 small fets (4x ignition drivers for external ignitors), a case, some DB connectors, and have themselves a basic but kick arse EMS for under 300US with plenty of room for expansion later piece at a time.

Once the foundations are there and we have a user base built around a low end setup like that, we can start thinking about other alternatives like "NanoFreeEMS" and "MonsterFreeEMS" at each end of the "does bare minimum and is tiny" and "does everything and includes the kitchen sink and fries with that" scale.

Thoughts?

Thanks,

Admin.

[Costa]

+1



Edit:Undo first edit

[Fred]

Legend! (for the feedback, not agreeing with me, though, I liked that too)

Learn by good example people ^ feedback is good.

:-)

[Tony]

+1 keep it basic at first then work your way into more complex stuff its always easier to add what you need than to add to much get confused and have a mess . Through hole is fine SMD is super fine.LOL


I was afraid of the SMD stuff till i did it i solder .020 pitch stuff all the time in fact i can solder a 28 pin .020 pitch lead component in less time that it takes me to solder a through hole resistor and clip the leads plus you dont need a solder sucker to suck the solder out of the holes once you remove the component key is having proper soldering tools and plenty of flux but you end up with a more robust board once its done and you can place components on both sides of the board effectively doubling your board to component size.

I only say this because i have about 3 million SMD resistors and capacitors here and i need to do something with them.LOL

But for a proto type board through hole would defiantly be the way to go and the option for both would be nice i know for bikes we cant have huge ECU's onboard theres just no place to put them and SMD is the only way to go to fit the required stuff in a box that not the size of a laptop.

[Fred]

Thanks Tony!

I personally really like the idea of a fully SMD DIY board, BUT, I feel that if that were the only option, it would scare too many people off. I have only through hole stuff here too. The local prices were so stupid (look up VAT) that I had someone personally import my component supplies from New Zealand!

I've been dreaming of a setup that is barely bigger than the adapt card myself. I think with two equaly sized boards sandwiched onto it, you could create a minimalistic 4 cyl ECU inside about 90x60x40 or so :-) That would be an awesome little project for offroad stuff, bikes, jetskis etc. Of course, if I don't get off my arse and write some more code soon that will likely never happen!

Cheers,

Admin.

[Tony]

Thanks Tony!

I personally really like the idea of a fully SMD DIY board, BUT, I feel that if that were the only option, it would scare too many people off. I have only through hole stuff here too. The local prices were so stupid (look up VAT) that I had someone personally import my component supplies from New Zealand!

I've been dreaming of a setup that is barely bigger than the adapt card myself. I think with two equaly sized boards sandwiched onto it, you could create a minimalistic 4 cyl ECU inside about 90x60x40 or so That would be an awesome little project for offroad stuff, bikes, jetskis etc. Of course, if I don't get off my arse and write some more code soon that will likely never happen!

Cheers,

Admin.

Oh yes it would for sure scare people off if this was the only option heck when i first started through hole stuff was kinda scary to me i was always afraid i was going to screw something up. (and i have screwed my fair share of stuff up)

Yes i know all about the VAT over there when i sourced the ECU connectors for my box i wanted to pull my hair out with all the hoops the supplier wanted me to jump through just to be able to buy them thats why i just found someone from over here to buy them for me the VAT took a $5.00 connector and turned it into a $20.00 one.

[Fred]

I was quite keen to get the logic analyser based on an FPGA board, however, it's 100US in the US, 107US shipped anywhere in the US, it would be 135US shipped to NZ, but to ship it here to the UK it would be 170US landed and received! Not good. I know just what you mean.

Admin.

[GartnerProspect]

First off, I'd like to say I'm very happy to see this board. I've been thinking that the MS project may have lost some of its original philosophy, or more accurately, it had just evolved past what I appreciated and enjoyed. Maybe I just fear change...

Much respect to the B&G and others, but I'm happy to see others going their own direction.

On that note, I've been working on a design of my own looking at some of the very same goals I think this project has and I'll contribute some of my findings.

I'm finding that through hole components are becoming harder and harder to find. Namely in MCUs. I seriously doubt we'd be able to get away from a SMT MCU if we want all the features and future availibility. But after some deep thought and looking at some fine pitch QFP chips, I'm pretty convinced that it's not a major obstacle to have a handful of SMT components.

With my current layout and design, it takes advantage of a stacked board design for growth. What I always hated on my MS implementations were the rats nest of wires required when you stepped up to Boost control, water injection, multiple trigger, COP, etc. By tying a majority of availible I/O to a PC104 style stacked board you can provide for nest-less expandablility and reduce overall cost for people that don't need ALL the bling on one board. I can expand on this concept at a later date.

Any under taking like this is going to take baby steps. B&G have been at this for over 10 years now, and I only found it 6 or so years ago - and it will still be a long time before I'd consider myself an expert on the subject!

yay!
-Brad

[Fred]

Have a look at the hardware feature wishlist thread for my thoughts on board layout and circuit design :-) pc104 gets it's mention in there too ;-)

[AbeFM]

Ok, so my comments are a bit late, but I'd put in another vote for surface mount.

With all the things you're doing to not bow down to the clueless (which, I think is being done too much, and that it should be done less), I'll say this: Most of the people in the MS world are scared about soldering at all. So having 50+% SMD won't scare them since they don't know to be scared. Don't say it can't be done, and no one will know how hard it is.

Here, at least, it would bring the costs down. Especially when looking at doing banks of circuits (8 peak and hold injectors, 8 COP, etc etc) buying quad- and eight-pak resistors and gates will be better for packaging, and lower cost.

I think it should be done on a case by case basis. Ideally, finding something for which there's an equivalent part, so the schematics are the same between versions. We do a lot of that here, leaving footprints for bigger parts, though from SMD to through hole, it would be harder to maintain layout.

This is how I think about it - the time it takes to solder the parts you pay for once. The space you save keeps paying you back every day.