How to set pause key for libretro emulators?

mitu

When enabling the hotkey in RetroArch, you can't use a single key for the command, you need to use the hotkey.
However, there is a workaround to that, albeit a bit more convoluted. RetroArch has a network input interface, to which you can send the Pause command through a script. You can trigger said script using the trigerhappy service (which is enabled and started by default on a RetroPie image).

Create a file named pause-retroarch.conf in the /etc/triggerhappy/triggers.d and add the following line:

KEY_P /home/pi/pause-ra.sh

You'll need to use sudo to create the file, since this is a system file.

sudo nano /etc/triggerhappy/triggers.d/pause-retroarch.conf

Create a script that will send the pause command to RetroArch in /home/pi/pause-ra.sh with the following lines

#!/bin/bash
echo -n "PAUSE_TOGGLE" | nc  -u -w1 127.0.0.1 55355

and then make the script executable

chmod +x /home/pi/pause-ra.sh

Install netcat - used by the script

sudo apt -y install netcat

Modify the RetroArch configuration configuration file in \\retropie\configs\all\retroarch.cfg and add a line at the end with

network_cmd_enable = "true"

Reboot and see if the P key pauses RetroArch.

agent4125

@mitu Thanks very much. It's a shame RA can't do it without a hotkey!

I tried the script as you mentioned above (checked everything twice) but still pressing the button on its own doesn't do anything. It still works with the hotkey though.

mitu

I may have omitted something in the thd script (pause-retroarch.conf. The line

KEY_P /home/pi/pause-ra.sh

should be

KEY_P 1 /home/pi/pause-ra.sh

Check if the service is started automatically with

systemctl status triggerhappy.service

agent4125

@mitu thanks again. No luck though. tweaked the .conf file as mentioned, and checked triggerhappy was running, which it was. Still can only get pause to work if I hold the hotkey.

I also ran the script ./pause-ra.sh directly from the terminal while lr-mame2003 was running. This did nothing either.

Cheers

mitu

@agent4125 Then maybe the network input interface is not enabled. Did you ever used Save Configuration in RetroArch when configuring it ? This would generate a full configuration file that's different than the .cfg I mentioned.

agent4125

@mitu I had set the network_cmd_enable = "true", is there another setting I should be looking out for. It's "true" in retroarch.cfg.

I may have saved configuration at some point in the past (before I knew better I guess), but manually editing the main retroarch.cfg for other settings works fine.

mitu

@agent4125 I think I know why it doesn't work - there's an extra parameter in the pause script - I amended the original post and removed it. Please re-do the pause-ra.sh script with the new command and try again.

agent4125

Bingo! That works.

Many thanks :)

jlr2000

@mitu Many thanks for sharing this information, I know this is an older post but is it possible to map multiple buttons using this script? I'm hoping to not use the pause key but a button combo such as Coin 2 and Player 2 simultaneously. This would allow me to have some consistency between emulators for Pause (libretto mame/advancemame) and avoid using the hotkey.

Thanks again for sharing this information!

mitu

@jlr2000 I don't know, in theory it knows about multiple key presses allowing for up to 5 modifiers. Just give it a test and see how it behaves.

jlr2000

@mitu Will do, thanks!