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Emady
Newbie

Joined: 02/02/2016
Location: United Kingdom
Posts: 23

Posted: 08:46pm 17 Dec 2020

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Hi All,

After a lot of lurking I have started my custom build of a CMM2. Initially I wanted to do my own PCB but decided against that. Instead I took an old eeePC netbook and used it as a donor in which I fit the STM32 shield and all other required parts.

The build is well under way, I have done the smoke test today and all went well �

I wanted to use the original keyboard of the netbook so I built a USB Keyboard controller following this instructable:

https://www.instructables.com/How-to-Make-a-USB-Laptop-Keyboard-Controller/

I tested the controller on my laptop and it works great but when plugged in the CMM2 it does not work. Plugging a normal keyboard in the CMM2 works. Anyone tried a custom keyboard controller based on the Teensy with the CMM2?

Here are some photos of the build and the smoke test setup:

Any advice to help me make my CMM2 Netbook a reality?

Thanks,
Elia
Edited 2020-12-18 06:48 by Emady

JohnS
Guru

Joined: 18/11/2011
Location: United Kingdom
Posts: 4147

Posted: 02:12pm 19 Dec 2020

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Cool idea.

The instructable talks about a composite USB device which may well be where the problem is.

I suspect you want it to look like a keyboard only.

John
Edited 2020-12-20 00:13 by JohnS

Cyber

Senior Member

Joined: 13/01/2019
Location: Ukraine
Posts: 161

Posted: 04:56am 21 Dec 2020

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I remember people mention on forum that CMM2 worked with almost every USB keyboard, but there were few models that did not work.
I assumed USB keyboard protocols has several modifications and CMM2 might not support all of them, but only most popular ones.

toml_12953
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Joined: 13/02/2015
Location: United States
Posts: 479

Posted: 05:18am 21 Dec 2020

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Cyber said I remember people mention on forum that CMM2 worked with almost every USB keyboard, but there were few models that did not work.
I assumed USB keyboard protocols has several modifications and CMM2 might not support all of them, but only most popular ones.

One restriction is that the keyboard must not have a USB hub in it. It can't have USB ports in it for example. Some keyboards that have backlit keys use a USB hub to run the LEDs and don't work. For a wireless dongle, it can't support both a mouse and keyboard, only a keyboard.

Emady
Newbie

Joined: 02/02/2016
Location: United Kingdom
Posts: 23

Posted: 01:01pm 21 Dec 2020

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Thanks for the replies, I looked at the Teensy website and forums and sees it has something to do with the way the USB Keyboard is emulated. The code for the controller was compiled to emulate a pure USB Keyboard only, nothing else but somehow the CMM2 does not recognise it.

Programming USB drivers, etc... is beyond my capabilities, will try a bit more to see if I get anywhere, if all fails will see if I can fit a similar size commercial keyboard in the laptop to make it work.

Everything else is working, I got the original display to work, finishing off the battery charger and power supply, just this keyboard .....

Will keep you posted
Thanks,
Elia

Cyber

Senior Member

Joined: 13/01/2019
Location: Ukraine
Posts: 161

Posted: 01:12pm 21 Dec 2020

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Emady said if I can fit a similar size commercial keyboard in the laptop to make it work

This might be a bulletproof option. )

Emady said Everything else is working, I got the original display to work, finishing off the battery charger and power supply

Turns out a very nice project!

Looking at the photo display loooks like wide AR, but CMM2 has 4:3 AR. The image woill be horizontaly disproportionaly stretched if display is really wide AR.

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