Thinkpad T470 Trackpad

Projects Networking, Protocols, and Devices
1

Hello everyone,

I've been working on a project for quite some time now. I want to use the trackpad on my ThinkPad T470 as an external device. For testing purposes, I wanted to connect the trackpad to an Arduino Uno first, and later to a ProMicro-C on a PCB with a few extra buttons and a rotary encoder. The PCB design is complete, and the input for the buttons and the encoder are working. I'm just stuck with the trackpad. I have the schematics for the trackpad:

schema
schema906×480 29.8 KB

I'm no expert, but I'd say this is a PS/2 device. For me, that means I need the following pins: GND (12), VCC3B_PAD (6), IPDDATA (3), and IPDCLK (4).
I've tried various combinations, but I'm not getting any signal.

I connected the Arduino as follows (I've already switched between 3.3V and 5V):

schema_2
schema_2593×318 7.27 KB

I've tried the code from various similar projects, but so far, all without success. So, two questions:
#1: Is my setup fundamentally correct, or has the error crept in here?
#2: Does anyone have a code snippet I can use to test the trackpad in the Arduino IDE? All the snippets I've tried so far have been unsuccessful.

Thanks in advance!

2

You can try this one:

This is an example of the "PS2-Mouse-Arduino" library. The library developer never submitted it to the Arduino Library Manager, so you will need to install it via an alternative method:

  1. Click the following link to open the library's GitHub repository homepage in your web browser:
    https://github.com/kristopher/PS2-Mouse-Arduino
  2. Click the "Code ▾" button you see on that page.
  3. Select Download ZIP from the menu.
    A download of the ZIP file of the library will start.
  4. Wait for the download to finish.
  5. Select Sketch > Include library > Add .ZIP Library from the Arduino IDE menus.
    The "Select the zip file containing the library you'd like to add" dialog will open.
  6. Select the downloaded file from the dialog.
  7. Click the "Open" button.
    The dialog will close.
  8. Wait for the installation process to finish, as indicated by a notification at the bottom right corner of the Arduino IDE window:

    ⓘ Successfully installed library from ...

After installing the library, you can open the example sketch by selecting File > Examples > PS2-Mouse-Arduino > Simple from the Arduino IDE menus.

Make sure to adjust these lines in the example to reflect the pins on the Arduino to which you connected the trackpad:

pert 4

Closing in favor of @null_x_17's cross-post, which has more replies:

@null_x_17 cross-posting is against the Arduino forum rules. The reason is that duplicate posts can waste the time of the people trying to help. Someone might spend a lot of time investigating and writing a detailed answer on one topic, without knowing that someone else already did the same in the other topic.

Repeated cross-posting can result in a suspension from the forum.

In the future, please only create one topic for each distinct subject matter. This is basic forum etiquette, as explained in the "How to get the best out of this forum" guide. It contains a lot of other useful information. Please read it.

Thanks in advance for your cooperation.