Detect TV remote buttons being pressed with CEC client

Question

My TV supports CEC and is connected to my Raspberry Pi with HDMI. I've installed cec-client on the Pi and followed this tutorial, but it only explains how to turn the TV on and off with the Pi. What I want is to somehow grab a signal in the Pi when a button on the TV remote is pressed, to know what button is pressed. I tried running cec-client until it outputs "waiting for input", but pressing buttons on the TV remote didn't do anything.

J.Doe · Answer 1 · 2019-04-18T12:49:16.357

I've had the same issue, that the remote controll buttons haven't been recognized after typing the command cec-client. In order to work I had to refocus the TV's input source after the waiting for input occured, so for example I changed from HDMI 1 (thats where the Pi was connected to) to HDMI 2 and back to HDMI 1 again via the remote manually.

After that I was able to catch the remote control signals.

If you want to controll your Pi you also need to download xdotool in order to simulate keyboard input. Type:

sudo apt-get install xdotool

Second step is to create an executable script with

touch name.sh
chmod +x name.sh

#open the script with your favorite editor
nano name.sh

You can now start to program your controlls.

#!/bin/bash
while read oneline
do
   keyline=$(echo $oneline | grep " key ")
   if [ -n "$keyline" ]; then
      strkey=$(grep -oP '(?<=sed: ).*?(?= \()' <<< "$keyline")
      strstat=$(grep -oP '(?<=key ).*?(?=:)' <<< "$keyline")
      strpressed=$(echo $strstat | grep "pressed")

      if [ -n "$strpressed" ]; then
         case "$strkey" in
            "1")
                xdotool key "1"
                ;;
            "2")
                xdotool key "2"
                ;;
            "3")
                xdotool key "3"
                ;;
            "4")
                xdotool key "4"
                ;;
            "5")
                xdotool key "5"
                ;;
            "6")
                xdotool key "6"
                ;;
            "7")
                xdotool key "7"
                ;;
            "8")
                xdotool key "8"
                ;;
            "9")
                xdotool key "9"
                ;;
            "0")
                xdotool key "0"
                ;;
         esac
      fi
   fi
done

This is a simple programm that sends the digits as keys when pressed the according button on the remote.

Now you can execute your script

cec-client | ./name.sh

It should be working now

If you want to learn more about that check out this link: https://ubuntu-mate.community/t/controlling-raspberry-pi-with-tv-remote-using-hdmi-cec/4250

It tells you also how to auto execute the script when booting

Futhermore you can find xdotool commands here: https://www.linux.org/threads/xdotool-keyboard.10528/

Detect TV remote buttons being pressed with CEC client

1 Answers1