A shell script that updates the RGB on my razer mouse dock based on the mouse's charge level

dock-charge.service

# put in /etc/systemd/system, then do $ sudo systemctl enable dock-charge.service
[Unit]
Description=Charge LED Monitor
After=syslog.target

[Service]
ExecStart=/usr/local/bin/dock-charge.sh
Restart=always

[Install]
WantedBy=multi-user.target

dock-charge.sh

#!/bin/bash

# This script depends on openrazer. I use this script as a systemctl service.

# Function to find the device path with the charge_level handle
find_charge_handle() {
  for device_path in /sys/bus/hid/drivers/razermouse/*; do
    if [[ -f "$device_path/charge_level" ]]; then
      echo "$device_path"
      return  # Exit the function after finding the handle
    fi
  done
  echo "charge_level handle not found"  # Handle not found
  exit 1  # Exit the script with an error
}

# Function to find the device path with the matrix_effect_static handle
find_led_handle() {
  for device_path in /sys/bus/hid/drivers/razeraccessory/*; do
    if [[ -f "$device_path/matrix_effect_static" ]]; then
      echo "$device_path"  # Return the full path
      return
    fi
  done
  echo "matrix_effect_static handle not found"
  exit 1
}

# Constants for device handles and color ranges
charge_handle="$(find_charge_handle)/charge_level"
# Get the device path with the LED handles
led_handle="$(find_led_handle)/matrix_effect_static"
breath_handle="$(find_led_handle)/matrix_effect_breath"
green_min=200
yellow_min=100
orange_min=50
critical_level=15

# Function to set LED colors based on charge level
set_led_colors() {
  charge_level=$(<"$charge_handle")

  if [ "$charge_level" -ge "$green_min" ]; then
    color_hex="\x00\xFF\x00"  # Green
  elif [ "$charge_level" -ge "$yellow_min" ]; then
    color_hex="\xFF\xFF\x00"  # Yellow
  elif [ "$charge_level" -ge "$orange_min" ]; then
    color_hex="\xFF\xA5\x00"  # Orange
  else
    color_hex="\xFF\x00\x00"  # Red
  fi

  echo -n -e "$color_hex" >"$led_handle"

  if [ "$charge_level" -lt "$critical_level" ]; then
    echo -n -e "$color_hex" >"$breath_handle"  # Send red to breath_handle too
  fi
}

# Main loop to continuously update LEDs and output
while true; do
  set_led_colors
  echo "Charge level: $charge_level, Color: $color_hex"
  sleep 5
done