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Old 11-16-2015, 11:54 AM   #61
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Originally Posted by Joe Perez View Post
But, on topic- Reverant's comment inasmuch as "the CPU board is not generally repairable," while true, misses the point entirely. For the average* user, the value of the schematics is not that they allow you to repair the CPU board, but they they enable you to design & modify supporting circuits which surround the CPU board. Without the schematics, you're left guessing as to how pins on the DIP-40 and header connections interface with the CPU itself.
That part is in the current edition of the MS3 manual. I can tell you that the 34 and 10 pin headers are tied directly to the CPU pin outputs, with the exception of the flex fuel input, which is the same as on the MicroSquirt.
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Old 11-16-2015, 12:01 PM   #62
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Originally Posted by Braineack View Post
what's the stock housing? a MS1/2 case?
Miata stock ECU.
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Old 11-16-2015, 12:35 PM   #63
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Originally Posted by Reverant View Post
99.5% of the time, when the board is damaged, the damage is on the processor, which you can't fix yourself, even if you had the schematics.
I replaced a processor once. Cheap from digikey. Can be done with inexpensive tools and mediocre solder skills.

The hardest part was putting the boot loader back on... which is definitely something I couldn't do myself.

However it does help to live within a short drive of a megasquirt developer.
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Old 11-16-2015, 12:36 PM   #64
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peter florance is also just 1 day usps priority from us :P
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Old 11-16-2015, 01:04 PM   #65
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Originally Posted by y8s View Post
The hardest part was putting the boot loader back on... which is definitely something I couldn't do myself.
See, that's the thing that bugs me. B&G have already secured the design with the secret-sauce bootloader. Any pirate who is sufficiently competent to extract and reproduce that process will find reverse-engineering the hardware trivial by comparison.

B&G aren't gaining any added security by refusing to release the board schematic, they're just making life annoying for advanced end-users.

I could draw a parallel to handgun laws in the US, but I don't want to drift the thread. We already have a thread for that.
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Old 11-16-2015, 02:11 PM   #66
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Originally Posted by Joe Perez View Post
I'd love to.

When I designed and built the Hellasquirt board* years ago, I had a copy of the Motorola technical manual for the 68HC908 on my desk, so that I could see exactly how all of the various IO pins worked. Yes, I could have backwards-engineered this info from looking at the 3.0 PCA schematic, but there are so many badly-designed circuits on there that I wanted to be sure I had the best data available right from the source.

The fact that there are active and passive components on the MS3 CPU (other than the CPU itself) means you can't make blind assumptions about how the pins on the actual processor itself are connected to the DIP40 and header connectors.

* = Yes, I realize that this makes me one of the counterfitters that B&G are so concerned about. I built this board for recreational purposes, only made one of them, and removed it from the car before I sold it. I still have it in a box somewhere.
Most pins on the 40-way DIL and the 10/34way IDC connectors are direct connections on the MS3 processor. The rest of the passives and ICs are there for:

1) FT232RL USB-to-serial conversion
2) SD Card datalogging
3) IAC stepper driver
4) CAN driver

And that's about it. There's nothing magical about it. I would literally not need the schematics to design a mainboard if I had the info above 3 years ago.
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