Toggle Touchscreen for reMarkable 1

How to associate left+right keys to toggle the capacitive touchscreen of the reMarkable 1 tablet

The pen (EMR technology) can still be used. As a left-handed person, my left palm always tend to close the current note. Even as a right-handed person, the capacitive display can interact with the palm in a non-desired way while writing/sketching with the pen.

This tutorial is intended for people with beginner-medium knowledge of Linux and terminals.

Disclaimer

• This procedure only works with a reMarkable table model 1 (denoted here rM1): with three physical buttons on the front.
• The script has to be adapted depending on the version of the firmware to match the correct device index of the capacitive screen and the buttons.
• I manage to do the whole procedure from my Windows 11 with WSL (Ubuntu 22) and connected to the rM1 with USB.
• This explanation and code is derived from Ente on his personal website
• It also involves the following repos:
  • evkill: a silencer for evdev input devices.
  • evtest: a tool to print evdev kernel events

Tutorial - Installation

I will guide you step-by-step to test the feature and make it run by default on the tablet.

Part 1: Installing the main script and testing it

1. Make sure to know the IP Address and root password of your reMarkable 1. In what follow, replace the IP address with the correct one depending on your case: You can get the current IP address of the rM1 and the root password in Setting > General > Help > About Copyrights and licenses > Bottom of the page. The default address for a USB connection is 10.11.99.1

The following instruction are to run in a Linux terminal (it can also be WSL) located in this repository. Throughout the procedure, you will be prompted to type the rM1 password. If you don't want to type it all the time, you can also create a SSH key pair.

The two first steps download and compile the binaries that we will copy to the rM1. You can also directly skip them at start at step 3.

1. Optional: A binary file for evkill is already present in the bin/ folder of this repository. But you can also download the latest release for rM1's architecture (armv7l).

./scripts/get-evkill.sh

2. Optional: Similarly, a binary file for evtest is already in the bin/ folder of this repo. If you want to compile yourself the binary, you need to have docker installed. If you cannot run docker run hello-world, install it following the instruction here. Download and cross-compile evtest:

./scripts/compile-evtest.sh

Alternatively, the binary is already present in

3. Copy the executables evkill, evtest, and the main script toggle-touchscreen.sh to the user directory of the remarkable. Don't forget to replace the IP address if necessary.

scp bin/evkill root@10.11.99.1:. && \
scp bin/evtest root@10.11.99.1:. && \
scp scripts/toggle-touchscreen.sh root@10.11.99.1:.

4. Optional: In this step, we test the main script. In one command, connect to the rM1 and run the main script. Don't forget the -t -t to stop the script after leaving the ssh:

ssh -t -t  root@10.11.99.1 ./toggle-touchscreen.sh

Toggle the touchscreen by pressing briefly and simultaneously on the LEFT and RIGHT buttons. You should read something like this:

Event: time XXX, type 1 (EV_KEY), code 106 (KEY_RIGHT), value 1 -> LEFT false , RIGHT: true
Event: time XXX, type 1 (EV_KEY), code 105 (KEY_LEFT), value 1 -> LEFT true , RIGHT: true
=> Disable touchscreen: /home/root/evkill /dev/input/event2
Event: time XXX, type 1 (EV_KEY), code 106 (KEY_RIGHT), value 0 -> LEFT true , RIGHT: false
Event: time XXX, type 1 (EV_KEY), code 105 (KEY_LEFT), value 0 -> LEFT false , RIGHT: false

Now try to swipe your finger or touch anywhere. Tadaa 🪄!

The capacitive touchscreen is now ignored but you can still use the pen (if the capacitive touchscreen is still detecting, see the section Troubleshooter). You can stop this test by pressing the keys CTRL + C. Your touchscreen is detected again.

Part 2: Creating a service to manage the script

To automatically run the script at startup and keep it running in background, we will created a systemd service.

1. Copy the service file toggle-touchscreen.service to the appropriate location:

scp toggle-touchscreen.service root@10.11.99.1:/etc/systemd/system/

2. Enable the script to automatically run at startup and start it.

ssh root@10.11.99.1 \
 "systemctl enable toggle-touchscreen.service && \
  systemctl start toggle-touchscreen.service"

That's it!

Uninstall

To revert the changes on the rm1, just stop and disable the service.

ssh root@10.11.99.1 \
 "systemctl stop toggle-touchscreen.service && \
  systemctl disable toggle-touchscreen.service"

You can also remove the related files

ssh root@10.11.99.1 \
 "rm /etc/systemd/system/toggle-touchscreen.service \
  toggle-touchscreen.sh evkill evtest"

Troubleshooter

• If the main script can run but doesn't seem to work as planned: it might be that the device ID differs from the one specified in scripts/toggle-touchscreen.sh. Check the correspondence using

ssh root@10.11.99.1 ./evtest

And interrupt it with CTRL + C.

• The output should be something like

No device specified, trying to scan all of /dev/input/event*
Available devices:
/dev/input/event0: Wacom I2C Digitizer
/dev/input/event1: gpio-keys
/dev/input/event2: cyttsp5_mt
Select the device event number [0-2]:

From the previous output for instance, the mapping is the following:

Device	Name	Description
/dev/input/event0	Wacom I2C Digitizer	The EMR device for the pen
/dev/input/event1	gpio-keys	The hardware buttons
/dev/input/event2	cyttsp5_mt	The capacitive touchscreen

• In scripts/toggle-touchscreen.sh, make sure that the instructions DEVICE_BUTTONS=... and DEVICE_TO_KILL=... are matching respectively the input devices of gpio-keys (buttons) and cyttsp5_mt (capacitive touchscreen)