FREEEMS hardware schematic and PCB

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lekker
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FREEEMS hardware schematic and PCB

Post by lekker »

Hi All,

Fred told me to contact Gearhead for creating a dev board with CPU straight on it.
Can anyone point me the schematic either in Orcad /Altium Designer or pdf that I can start to produce what this group need. I have spare resource for that now. If the schematic is reviewed and checked then we can do that very quick. I mean few weeks.

I have a MS V3 board in the past and it works for me. I laos down loaded the MicroMS v2. as someone ponited to the site. What I am trying to say is this, I know the MS2 V3 and the Micro well.

Cheers,-L
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jharvey
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Re: FREEEMS hardware schematic and PCB

Post by jharvey »

Can I recommend looking into KICAD? I've been very happy with it. It has many features you simply can't get from those closed systems. Mostly the text editable files. I find it much easier to simply edit a text file than to drag and drop component after component, ect. I also find it much easier to edit component properties in a text editor, you don't have to right click every thing to change a simply attribute.

Also KICAD is about the only help file I've found helpful. So don't be scared to read it if you try it out.
lekker
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Re: FREEEMS hardware schematic and PCB

Post by lekker »

cool. Let me try KiCAD first, then report back shortly.
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Fred
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Re: FREEEMS hardware schematic and PCB

Post by Fred »

Thanks for jumping on the board, lekker! As I said to you, I'm holding things up with the hardware progress by not knowing what to do with the pins. Do look into kicad, I believe its the only open source tool worth using around. If you hate it, don't feel obliged to use it though.

After you next reply to this, I'll move it to the proper forum. (wouldn't want you wondering where it went...)

Fred
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Oskar
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Re: FREEEMS hardware schematic and PCB

Post by Oskar »

Over at Otaniemi Flying Finns our electronics people are using kicad and apparently are quite happy with it.
The user interface takes some getting use to, but after that is very efficient and powerful.

As stated in the general section, our hardware is almost complete.
Mayor work still needed with the software, and time is closing in quickly...
But I guess that's how things get done :)
lekker
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Re: FREEEMS hardware schematic and PCB

Post by lekker »

I guess I was not patient enough to keeping learning of the KiCAD, instead I use AD 2009.
What I plan to do for this is to fibracate 50 boards for people who would like to order at my PCBA cost.
The motive to doing this is that I was heard someone complains about the cost of a similar board from TA.
Thus, this would be an alternative supply.
My main objective to make contribution is on the main board (sensor, I/O..) to keep this group going as much as possible.

If feedbacks from this group are positive on this CPU board then I will going ahead immediately.
Attachments
9S12XDP512Schematic Prints.pdf
CPU board schematic with same PINOUT of TA's
(66.22 KiB) Downloaded 777 times
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jharvey
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Re: FREEEMS hardware schematic and PCB

Post by jharvey »

I just took a quick look, looks good to me. I'll try to take a closer look shortly. I didn't see a PCB layout, just the schematic. My longer term goal is to make a brain board that includes 2 cyl's and hall only RPM input. That way the brain board can be uses for small engines, and more cyl's can be added via FreeEMS 1.0.

Have you seen batchpcb.com? They do good things in keeping the cost's down.

Do you have a cost and ETA for when PCB's might be available?
lekker
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Re: FREEEMS hardware schematic and PCB

Post by lekker »

Board is done today. I will call it as Coreboard or CPUboard.
Here is the layout.
The next one I will work on is the main board (the sensor and control).
Cheers,
Attachments
FreeEMS_Board.pdf
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lekker
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Re: FREEEMS hardware schematic and PCB

Post by lekker »

Yes, I have looked some sources of PCB fabrication and PCBA as well. I think I have a pretty good ideal place to go for it with a minimum cost for the group. I will work out a costing sheet next time. - L
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jharvey
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Re: FREEEMS hardware schematic and PCB

Post by jharvey »

Looks good to me mostly. I have a couple smaller recommendations or thoughts.

The TA card transfers power via the 50 pin connector. There has been concern that these pins can't really handle the instantaneous power draws, and the pins often works as a restive connector for small current spikes. FreeEMS also wants to push the accuracy boundaries, so nice sharp rising and falling edges are going to be quite handy. Because of that the current practice is to add a jumper wire from the TA card to the power supply. If we have a self spun PCB, perhaps we can add a 0 ohm jumper for those that want to power it via 50 pin connector, and for those that want a heftier power supply can power it via other connector. If we place this power connector correct, it can also function as key preventing people from putting the brain on back-wards.

I think you have this drawn up as a 4 layer board. Is that right? A ground trace and / or flooded areas connected to GND will help prevent RFI. I ran a thin non conductive path around the parameter of the board on FreeEMS 1.0. A ground plane may take care of most of this, but I would recommend breaking out a path on the outside boundary, such that we can guarantee it's non conducting, unless it catches RFI.

Also if it's 4 layer, perhaps we can make it 2 layered. I don't think the power and ground paths are all that extensive, and it would be easier to attach a scope ground, if it's on the outside of the board. A 2 layered board would also be lower cost to MFG.

I'm not familiar with AD 2009. A quick google search didn't pop it up. Do you have a link? I'm curious is it something I can get for free, and I'm curious how well it works. I like the graphics you produced with it.

About assembly, I'm currently building a infrared re-flow oven from a infrawave toaster oven FC150R, the silicon horizon techFX re-flow 3.0 and futurelec's 40A Solid State Relay. Total cost with shipping was about $230. I'm still waiting for the relays. I have a tub of solder paste, so if you produce a solder mask, I may be able to populate the PCB's at a reasonable price.
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