We need to lay out a basic board

From DIY contraptions to sophisticated FreeEMS-specific designs! Plus general hardware development!
gearhead
LQFP112 - Up with the play
Posts: 120
Joined: Sun Feb 03, 2008 9:30 pm
Location: Chicago, USA

We need to lay out a basic board

Post by gearhead »

I see DaveBMW is doing his own thing. I know that Fred wants to use the TechArts board. We are standardized on the 112 pin chip on the TA board. I know there are some efforts going to a board that the TA chip will connect to. What we need is a plug compatible solution so that we can get on with the development, IMO.

I want to do a similar thing so I can get this rolling. I picked up DipTrace and will start laying out a board using the 112 pin chip that all this (FreeEMS) is based on. I hate all this duplication of effort. I'd like to focus some effort so that this can make some more forward progress instead of all the discussion. I do not want to buy a TechArts board as it will cost me the same to buy boards and solder the chip to it and we can make it a group buy of boards. I do not want to complicate things with a 114 pin chip. I do not want to complicate things with current sensing, etc. I want quick and clean and we know what is needed.

2 timing inputs (crank and cam)
7 adc inputs (CLT, IAT, TPS, MAP, EGO, BATT, spare)
6 injectors
6 ignition (low current)
4 generic outouts (fets)

Terminates in a 37 pin dip for plug compatibility with other systems so that it can be developed to the point that it is useful to run a car as well can plug in easily to a JimStim.

The other pins will be routed to a 0.1 header for a 'daughter card' which can then use the rest of the huge number of pins.

Does anyone have a format that I can import into DipTrace? Its native schematics are "dch". It can import p-cad pdif or Ascii files. I'd hate to redo all this work and would rather just edit what is already there.

Am I crazy?

Gearhead
User avatar
Fred
Moderator
Posts: 15431
Joined: Tue Jan 15, 2008 2:31 pm
Location: Home sweet home!
Contact:

Re: We need to lay out a basic board

Post by Fred »

No, not crazy, but be aware that pins may move! Same warning, different keen hardware designer :-)

PM Dave and see if he can export his work for you. I know the tool he is using is quite powerful. Jared will know if KiCad can export to those or not. Why not just use KiCad though??

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!
User avatar
jharvey
1N4001 - Signed up
Posts: 1607
Joined: Tue Jun 10, 2008 5:17 pm

Re: We need to lay out a basic board

Post by jharvey »

If you believe a crazy person, no your not crazy ;)

I know KICAD is an ASCII format, but I don't know if it can be imported into the package you noted. KICAD can export a gerber file, and I know KICAD can import a gerber file. So that may be the standard format to work from for interoperability.

I also might try to encourage making a connector board. I suspect it will save you a lot of work. The outputs of the layout I've done, are quite solid. I've been stewing over making a CPU board, but haven't as the software needs to develope. I havn't done a connector card because I don't have a need for it.
gearhead
LQFP112 - Up with the play
Posts: 120
Joined: Sun Feb 03, 2008 9:30 pm
Location: Chicago, USA

Re: We need to lay out a basic board

Post by gearhead »

Yes, I grabbed and have standardized on KiCAD. No problem. I grabbed the 1.03 and there are not a lot of devices in there. I want to use/leverage what you have done and would like to copy/paste it to design a basic board with a 12 pin device on that same board. This is similar to what Dave is doing, but his is also pretty specific to his setup. What I am trying to do is get one that is DB37 swappable with other systems so we can do the dev and swap it in and out as needed. I also noted that KiCad does not have the chip we are using, either. I hope Dave has made it or found it.

I am not so enamored of the TA board as it is 125.00 and I thought why not just get the 10.00 processor and solder it to a board and be done with it. The rest would be mostly through hole, with some SMD (DPAK). For similar money, you can have a board and make multiples. If there is HW available, there can be more people developing, I would suppose. I am not too worried about this being a rev 0.1 board and do not want to complicate it with tons of 'options' or investigation opportunities. I will be developing at least 4 inj, 4 ign (low level) 2 wheel input with 7 adcs, and spares of ADC and DIO. Basically similar input and output numbers to many of those that are running a MS/E. I want it to fit on a single 4 layer board. I am considering a riser for a daughter card that has the other 8 igniton and 2 injection. I feel if I get this designed and can order a run of boards, there may be interest especially if it costs less than 125.00 US per board.

Gearhead
User avatar
Fred
Moderator
Posts: 15431
Joined: Tue Jan 15, 2008 2:31 pm
Location: Home sweet home!
Contact:

Re: We need to lay out a basic board

Post by Fred »

Just to be clear, the 125 doesn't look quite so bad when you consider the extra cost of the BDM module. You also need to factor in the hassle of soldering the fine pitch stuff. I don't want someone thinking they can solder a chip to a board and "just use it". This just isn't true unfortunately. The serial monitor needs to be installed and a BDM is needed to do that.

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!
gearhead
LQFP112 - Up with the play
Posts: 120
Joined: Sun Feb 03, 2008 9:30 pm
Location: Chicago, USA

Re: We need to lay out a basic board

Post by gearhead »

http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 0144411356

I think I can swing the 12.00...


For that matter, we can lay out a bdm on the board and cut it off as a separate part. This is a simple part.

Gearhead
User avatar
jharvey
1N4001 - Signed up
Posts: 1607
Joined: Tue Jun 10, 2008 5:17 pm

Re: We need to lay out a basic board

Post by jharvey »

I'm still a bit stumped by the 1.03 thing. Is the the KICAD version?

You should be able to use the sub schematics I've got, and simply recreate the top schematic to add and remove what ever sub schematics you want. Also I've made a script that copies sub schematics. My intent is that you make any changes you feel are needed to files in the template folder, then run the script. Then your top drawing patches them all together. This saves a lot of work and helps keep things consistent.

When and if you make your own symbol (say for the MCU chip), I recommend creating the library, but also create the ??? I forget the name of the blasted thing. I seem to recall you click the greenish icon, not the red-ish icon. This allows the symbols to be included local, where the libraries require you to first install the libraries, which some times has permission problems. Basically it allows a fully contained package, if you click that greenish icon. I can try to elaborate a bit more later on.

I did this on Linux, so MS folks may have some trouble running the scripts if they don't have a cygwin of some kind of POSIX enviroment installed.
User avatar
AbeFM
Post Whore!
Posts: 629
Joined: Sat Feb 16, 2008 12:11 am
Location: Sunny San Diego
Contact:

Re: We need to lay out a basic board

Post by AbeFM »

Not reading any detail, but I believe there's a p-cad to kicad import tool on the kicad sourceforge page....

I sort of like the idea of a dedicated board (ok, I really like it) but... I think the idea of a standard, known working board is good for the first pass. The more simple the first gen IO card is the better.
User avatar
longracing
LQFP112 - Up with the play
Posts: 140
Joined: Wed Jul 16, 2008 9:21 am
Location: NSW, Australia

Re: We need to lay out a basic board

Post by longracing »

I'm also try to weigh up the options of getting the tech arts board versus directly getting the uC. The tech arts board doesn't seem too bad considering it has the clock, regs, serial I/O etc.

One option would be to use the tech arts board for the first development then you could even make your own daughter board for the freescale uC that would plug into the same 2 x 40 pin connectors if you needed. Or if you did make your own board with the uC, place two PTH in the lines coming out of the package. That way if you do need to re-route just cut the copper between the PTHs and wire up jumpers as required.
User avatar
AbeFM
Post Whore!
Posts: 629
Joined: Sat Feb 16, 2008 12:11 am
Location: Sunny San Diego
Contact:

Re: We need to lay out a basic board

Post by AbeFM »

Uh huh, that's the 'only' answer as far as I'm concerned. Do 'initial development' as soon as possible, just how everyone else is... Once things are up and running, and some lessons learned, I'd build a board with it on.
-Abe.
Post Reply