PCB layout - JHarvey

From DIY contraptions to sophisticated FreeEMS-specific designs! Plus general hardware development!
User avatar
jbelanger
LQFP144 - On Top Of The Game
Posts: 387
Joined: Sat Feb 23, 2008 8:58 pm
Contact:

Re: PCB layout - JHarvey

Post by jbelanger »

You're supposed to get one file per layer. Zip them up (with the drill file) and send that to the boardhouse. At least that's what I do but I use a different PCB software (Eagle).

Jean
User avatar
AbeFM
Post Whore!
Posts: 629
Joined: Sat Feb 16, 2008 12:11 am
Location: Sunny San Diego
Contact:

Re: PCB layout - JHarvey

Post by AbeFM »

I was hoping to load them into GC preview or some such to make sure everything lined up, but it won't load those pho files, and ... I can't check it.
User avatar
jharvey
1N4001 - Signed up
Posts: 1607
Joined: Tue Jun 10, 2008 5:17 pm

Re: PCB layout - JHarvey

Post by jharvey »

My understanding is that both techniques are acceptable. Gerber files technically have layers and you can technically put your different items on different layers. However, most software I've seen doesn't use the layers. Typically you zip up a pile of files and include a PDF or some such file that spec's things like board thickness, copper oz, score lines, ect. That PDF will allow the CAM dept to confirm that everything is what what you are expecting.

I've heard about GerbMerge. Good for when you are trying to panelize a board and some other basic tasks.

Yeah the 1,2,3 thing is that two rows of via that start with are titled 1a to 1v, then a next set titled 2a to 2p, and 3a to 3z. As you mentioned, those are for extra bits. Those 4 large vias must be for structural support on a terminal block.
User avatar
AbeFM
Post Whore!
Posts: 629
Joined: Sat Feb 16, 2008 12:11 am
Location: Sunny San Diego
Contact:

Re: PCB layout - JHarvey

Post by AbeFM »

Looks like I should have spent more time learning "wings", all that mess on that end of the board is the (self generated) footprint for the OEM connector, and the various screws which hold it down - which is why everything eventually goes there. Signals come out of the MS, most go to the jumper block directly (thanks Jean for the encouragement to try that) but some pass through drive circuits before they get there, or the cam/crk pickups. Some go down to the terminal blocks. After the jumpers, they all go out to the OEM, the only ones not using the jumper block is the battery low indicator (probably a mistake but I was out of pins), and ground.

My idea was you could make different standardized connectors with all the 'brains' already in them, to route wires correctly for one particular car or another. For a 2000 model, everything goes straight across, you could just solder the pads together. For a different year you might need to swap some things (I know you do). Plus, any diagnostics could also be worked into a plug - imagine a plug with a sense resistor on some lines.
User avatar
jharvey
1N4001 - Signed up
Posts: 1607
Joined: Tue Jun 10, 2008 5:17 pm

Re: PCB layout - JHarvey

Post by jharvey »

Fred wrote:I'd like to add that those parts were rejected because they don't have enough pins.
The EVK1101 eval board comes with the bottom of the barrel for AVR32. That's 75 MIPS, 48 or 64 IO, lower memory, ect. AVR is known for doing a good job in keeping architecture the same in a series of chips. Typically there are no require software changes to use the more powerful chips in that series. Using AT32AP7000 upgrades you to 160 IO, and 210 MIPS. More about the basic features in the AVR32 series of chips at this link.

http://www.atmel.com/dyn/products/param ... ection=ASC

About CAN. I personally don't agree with running CAN directly to the MCU, especially when it's the EMS. You certainly want a buffer chip of some sort. CAN is an industrial network, and is treated as such. It has a good chance of noise spikes that can fry our little MCU buddies in a hurry. For low $ you can get either signal conditioning chips, or you can get SPI to CAN chips. Because you really need this CAN chip any which way you look at it, I don't see a huge difference in CAN native chips or SPI interface chips. CAN and AVR's aren't a big deal. Check out this project.

http://www.candip.com/schematics-m162.htm

Includes posted design, and source code.

I should probably also ask for an update on the TA card part number. I see AD9S12E128M with uses the 112 pin MCU, but I also see lower cost version like AD9S12EQ128M0 with the 80 pin MCU. I'm glad to see that pricing now appears to be under $100. Looks like we have about 90 IO lines, and with XGATE less than 80 MIPS.
User avatar
AbeFM
Post Whore!
Posts: 629
Joined: Sat Feb 16, 2008 12:11 am
Location: Sunny San Diego
Contact:

Re: PCB layout - JHarvey

Post by AbeFM »

Heh, at work we just got a pair each of pic32's, avr's, the freescale chip and some 8051 thing... Kinda evaluating evironmental performance of these all. TOYS!
gearhead
LQFP112 - Up with the play
Posts: 120
Joined: Sun Feb 03, 2008 9:30 pm
Location: Chicago, USA

Re: PCB layout - JHarvey

Post by gearhead »

8InchesFlacid wrote:Ha, no, not at all. I mean, good guess but not right.

It's a board for a miata to a MS-II. I kinda want to put it in "non-free" but then again, this is really about the layout issues. I can send the whole zip but it's large? I just got tired of building harnesses and custom MS-II's for people who couldn't follow simple directions. You can't possibly charge enough to cover the work it takes to hand build these.

Do you know how to get gerbers out of this thing? All I got was "drill files" though they are PCO's and have traces so I'm not sure what it is - one per layer. Anyway, see attached.
This should be in a separate discussion thread, Abe. it confuses me and, I am sure, others. This is a replacement board for the MS V3 board, right? I agree that proper practice needs to be maintained and that there is no place to discuss it on the MS forums, but please keep this in a separate thread here.

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

Re: PCB layout - JHarvey

Post by Fred »

gearhead wrote:This is a replacement board for the MS V3 board, right?
No, not quite, I've started a thread just for it though :

Abe's Miata to MegaSquirt Adapter Project

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
longracing
LQFP112 - Up with the play
Posts: 140
Joined: Wed Jul 16, 2008 9:21 am
Location: NSW, Australia

Re: PCB layout - JHarvey

Post by longracing »

Has there been much progress on the FreeEMS board lately?
User avatar
jharvey
1N4001 - Signed up
Posts: 1607
Joined: Tue Jun 10, 2008 5:17 pm

Re: PCB layout - JHarvey

Post by jharvey »

I've made a couple small changes per the feed back I've received. I broke a ground path between two circuits, and made another small change. I haven't posted those files yet as they are very small changes. I've been waiting for software to determine what pins I should connect the different circuits to. I was hoping that release blah.21 could signify this coming into man hood. You know, still young but capable of making an impression on the world.

Out side of that, I'd be happy to hear more feed back and make more changes if need be.
Post Reply