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KeepIS

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Joined: 13/10/2014
Location: Australia
Posts: 1357

Posted: 01:43am 29 May 2020

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Just looking at making a mother board and I notice the Circuit for the CMM2 shows the USB/Serial convertor using Pin 10 to PGD and Pin 9 to PGC which is different to the Microbridge, which uses Pin 2 and 3.

I assume the Firmware for the PIC16F1455-I/P / MCP2221A-I/P been changed for use in the CMM2 with these pins and to allow for MCLRE and Auto Mode using pin Pin 4?

Mike.

It's all too hard.
Mike.

BobDevries

Senior Member

Joined: 08/06/2011
Location: Australia
Posts: 266

Posted: 02:16am 29 May 2020

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Is there any chance that you would make more than one CMM2 motherboard?

I should be able to source the other parts, I think, although I'm far from any *good* source.

Regards,

Bob Devries
Dalby, QLD, Australia

TassyJim

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Joined: 07/08/2011
Location: Australia
Posts: 5901

Posted: 02:20am 29 May 2020

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The microbridge uses pin 2 and 3 for programming micromites.
In the CMM2 we don't use that facility. The ICSP header was there as a way of programming the microbridge incircuit.

I found it easier to program the microbridge before installing so the ICSP header is not required.

There is also a Microchip IC that is already programmed as a USB-TTL device and it is pin compatible with the microbridge. Most of the pre-assembled units will use that IC.

Unless you are planning on a surface mount microbridge, I would forget about the ICSP header.

Jim

VK7JH
MMedit MMBasic Help

KeepIS

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Joined: 13/10/2014
Location: Australia
Posts: 1357

Posted: 03:50am 29 May 2020

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Thanks Jim, yes looking at the circuit again that should have rang a bell.

Is there any chance that you would make more than one CMM2 motherboard?
I should be able to source the other parts, I think, although I'm far from any *good* source.

Hi Bob,

I'm just going to knock something up using proto board, most of the parts are available at my local Jaycar, RS components are extremely fast at delivery if other parts are needed. As I was typing this, the Waveshare board arrived at the door, 7 days from China for $5.50 postage I expected it to be a few weeks at this time.

Pix from another forum member.
Proto MB
Edited 2020-05-29 14:32 by KeepIS

It's all too hard.
Mike.

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