HP Envy k151 HDMI-In switch

hdmi-toggle.service

# /etc/systemd/system/hdmi-toggle.service

[Unit]
Description=HDMI Button Watcher

[Service]
ExecStart=/usr/local/bin/k151_watch_hdmi_button.py
Restart=always

[Install]
WantedBy=multi-user.target

k151_watch_hdmi_button.py

#!/usr/bin/env python3

# requires python3-evdev on debian systems
# requires ddcutil
from evdev import InputDevice, categorize, ecodes
import subprocess
import re

dev = InputDevice('/dev/input/event2') # Confirm this with `evtest`

for event in dev.read_loop():
	if event.type == ecodes.EV_MSC and event.code == ecodes.MSC_SCAN and event.value == 0xff:
		output = subprocess.check_output(['/usr/bin/ddcutil', 'getvcp', '0x60', '--terse'])
		output = output.decode("utf-8").strip()

		match = re.search(r'VCP \d+ SNC x(\d+)', output, re.IGNORECASE)
		if match:
			current_input = match.group(1)
			print(f"Current Input: {current_input}")

			if current_input == "11":
				subprocess.run(['/usr/bin/ddcutil', 'setvcp', '0x60', '3'])
				print("Switched VCP 0x60 to DVI-in")
			else:
				subprocess.run(['/usr/bin/ddcutil', 'setvcp', '0x60', '17'])
				print("Switched VCP 0x60 to HDMI-in")
		else:
			print(f"ERROR: Could not parse VCP value. `{output}`")