How does my trackpoint module connect to controller

eefee

27 Nov 2020, 09:35

I have a new trackpoint module, it just has 6 pinouts which is :
NC SDA SCL INT GND VDD (which has no mouse button pinouts probablly)
I have seen almost every trackpoint module from thinkpad, which is different from mine
could anyone here please help me about the connection between my trackpoint module's pinouts with a controller?

Findecanor

27 Nov 2020, 11:45

SDA and SCL are used by the I²C protocol ... but the details of the protocol are different from device to device. There is some code for I²C support in the popular firmwares (TMK, QMK, ...) but they might be written for other devices than that module.
Unless someone else has already written support for your trackpoint module specifically, then you would need to get the documentation for it and do some programming.
It's impossible to tell more without knowing more about which kind of module you have.

NC = No Connect. (unused pin)
GND = Ground
VDD = Positive current. But at which voltage?

eefee

27 Nov 2020, 17:07

Findecanor wrote:
27 Nov 2020, 11:45
SDA and SCL are used by the I²C protocol ... but the details of the protocol are different from device to device. There is some code for I²C support in the popular firmwares (TMK, QMK, ...) but they might be written for other devices than that module.
Unless someone else has already written support for your trackpoint module specifically, then you would need to get the documentation for it and do some programming.
It's impossible to tell more without knowing more about which kind of module you have.

NC = No Connect. (unused pin)
GND = Ground
VDD = Positive current. But at which voltage?
thank you! have you ever seen in this forum that anyone has add such trackpoint module into keyboard?

Findecanor

27 Nov 2020, 17:26

eefee wrote:
27 Nov 2020, 17:07
Findecanor wrote:
27 Nov 2020, 11:45
SDA and SCL are used by the I²C protocol ... but the details of the protocol are different from device to device. There is some code for I²C support in the popular firmwares (TMK, QMK, ...) but they might be written for other devices than that module.
Unless someone else has already written support for your trackpoint module specifically, then you would need to get the documentation for it and do some programming.
It's impossible to tell more without knowing more about which kind of module you have.

NC = No Connect. (unused pin)
GND = Ground
VDD = Positive current. But at which voltage?
thank you! have you ever seen in this forum that anyone has add such trackpoint module into keyboard?
All trackpoint modules I've seen before have spoken PS/2.

I have seen a couple of tiny trackball modules that speak I²C though - not here but over on /r/ErgoMechKeyboards on Reddit and on Geekhack. There is the PAW3204OA and the Pimoroni trackball breakout. The PAW3204OA requires a level converter because it works at 2.7V (2.5-2.9V).

However, a I²C protocol could be anything .There is no standard for pointing devices over I²C ... (other than a Microsoft-proprietary protocol that wraps USB's HID protocol in I²C for use by detachable keyboards for their Surface tablets. But I doubt that is in use here)

What is it that you have?

eefee

28 Nov 2020, 03:56

Findecanor wrote:
27 Nov 2020, 17:26
eefee wrote:
27 Nov 2020, 17:07
Findecanor wrote:
27 Nov 2020, 11:45
SDA and SCL are used by the I²C protocol ... but the details of the protocol are different from device to device. There is some code for I²C support in the popular firmwares (TMK, QMK, ...) but they might be written for other devices than that module.
Unless someone else has already written support for your trackpoint module specifically, then you would need to get the documentation for it and do some programming.
It's impossible to tell more without knowing more about which kind of module you have.

NC = No Connect. (unused pin)
GND = Ground
VDD = Positive current. But at which voltage?
thank you! have you ever seen in this forum that anyone has add such trackpoint module into keyboard?
All trackpoint modules I've seen before have spoken PS/2.

I have seen a couple of tiny trackball modules that speak I²C though - not here but over on /r/ErgoMechKeyboards on Reddit and on Geekhack. There is the PAW3204OA and the Pimoroni trackball breakout. The PAW3204OA requires a level converter because it works at 2.7V (2.5-2.9V).

However, a I²C protocol could be anything .There is no standard for pointing devices over I²C ... (other than a Microsoft-proprietary protocol that wraps USB's HID protocol in I²C for use by detachable keyboards for their Surface tablets. But I doubt that is in use here)

What is it that you have?
it is developed from a small electronic company who sells on alibaba.1688. but it's not VI, don't support mouse buttons and press-select, so maybe I should turn to disassemble one from old thinkpad.

cakeanalytics

28 Nov 2020, 17:19

Don't know about your specific track point, but this guy has pinout for several old think pad track points like r61 and t40
https://github.com/alonswartz/trackpoint

Also think pad track point doesn't have mouse buttons either

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