diff --git a/examples/install-service.sh b/examples/install-service.sh
index 7da0f41..61988df 100755
--- a/examples/install-service.sh
+++ b/examples/install-service.sh
@@ -1,268 +1,127 @@
-#!/bin/bash
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Fan SHIM Installer for Debian 12+
+# Updated for Python 3.11–3.13 compatibility
 
-DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )"
 ON_THRESHOLD=65
 OFF_THRESHOLD=55
-HYSTERESIS=5
 DELAY=2
+BRIGHTNESS=255
+LOW_TEMP=$OFF_THRESHOLD
+HIGH_TEMP=$ON_THRESHOLD
 PREEMPT="no"
-POSITIONAL_ARGS=()
 NOLED="no"
 NOBUTTON="no"
-BRIGHTNESS=255
 EXTCOLOURS="no"
-PYTHON="python3"
-PIP="pip3"
 PSUTIL_MIN_VERSION="5.6.7"
-
-ON_THRESHOLD_SET=false
-OFF_THRESHOLD_SET=false
-
-SERVICE_PATH=/etc/systemd/system/pimoroni-fanshim.service
-
-USAGE="sudo ./install-service.sh --off-threshold <n> --on-threshold <n> --delay <n> --brightness <n> --low-temp <n> --high-temp <n> --venv <python_virtual_environment> (--preempt) (--noled) (--nobutton) (--extended-colours)"
-
-# Convert Python path to absolute for systemd
-PYTHON=`type -P $PYTHON`
-
+SERVICE_PATH="/etc/systemd/system/pimoroni-fanshim.service"
+
+PYTHON=$(command -v python3 || true)
+PIP=$(command -v pip3 || true)
+
+USAGE="Usage: sudo ./install-fanshim-service.sh [options]
+Options:
+  --on-threshold <n>     Temperature (°C) to turn fan ON (default 65)
+  --off-threshold <n>    Temperature (°C) to turn fan OFF (default 55)
+  --delay <n>            Poll delay in seconds (default 2)
+  --brightness <n>       LED brightness (0–255, default 255)
+  --preempt              Allow fan preemption
+  --noled                Disable LED
+  --nobutton             Disable button support
+  --extended-colours     Enable extended LED colour scheme
+  --venv <path>          Use Python virtual environment
+  -h, --help             Show this help message
+"
+
+# Parse arguments
 while [[ $# -gt 0 ]]; do
-	K="$1"
-	case $K in
-	-p|--preempt)
-		if [ "$2" == "yes" ] || [ "$2" == "no" ]; then
-			PREEMPT="$2"
-			shift
-		else
-			PREEMPT="yes"
-		fi
-		shift
-		;;
-	-l|--noled)
-		if [ "$2" == "yes" ] || [ "$2" == "no" ]; then
-			NOLED="$2"
-			shift
-		else
-			NOLED="yes"
-		fi
-		shift
-		;;
-	-b|--nobutton)
-		if [ "$2" == "yes" ] || [ "$2" == "no" ]; then
-			NOBUTTON="$2"
-			shift
-		else
-			NOBUTTON="yes"
-		fi
-		shift
-		;;
-	-o|--on-threshold)
-		ON_THRESHOLD="$2"
-		ON_THRESHOLD_SET=true
-		shift
-		shift
-		;;
-	-f|--off-threshold)
-		OFF_THRESHOLD="$2"
-		OFF_THRESHOLD_SET=true
-		shift
-		shift
-		;;
-	-G|--low-temp)
-		LOW_TEMP="$2"
-		shift
-		shift
-		;;
-	-R|--high-temp)
-		HIGH_TEMP="$2"
-		shift
-		shift
-		;;
-	-d|--delay)
-		DELAY="$2"
-		shift
-		shift
-		;;
-	-r|--brightness)
-		BRIGHTNESS="$2"
-		shift
-		shift
-		;;
-	--venv)
-		VENV="$(realpath ${2%/})/bin"
-		PYTHON="$VENV/python3"
-		PIP="$VENV/pip3"
-		shift
-		shift
-		;;
-	-x|--extended-colours)
-		if [ "$2" == "yes" ] || [ "$2" == "no" ]; then
-			EXTCOLOURS="$2"
-			shift
-		else
-			EXTCOLOURS="yes"
-		fi
-		shift
-		;;
-	*)
-		if [[ $1 == -* ]]; then
-			printf "Unrecognised option: $1\n";
-			printf "Usage: $USAGE\n";
-			exit 1
-		fi
-		POSITIONAL_ARGS+=("$1")
-		shift
-	esac
+  case "$1" in
+    --on-threshold)   ON_THRESHOLD="$2"; shift 2;;
+    --off-threshold)  OFF_THRESHOLD="$2"; shift 2;;
+    --delay)          DELAY="$2"; shift 2;;
+    --brightness)     BRIGHTNESS="$2"; shift 2;;
+    --preempt)        PREEMPT="yes"; shift;;
+    --noled)          NOLED="yes"; shift;;
+    --nobutton)       NOBUTTON="yes"; shift;;
+    --extended-colours) EXTCOLOURS="yes"; shift;;
+    --venv)           VENV="$(realpath "${2%/}")/bin"; PYTHON="$VENV/python3"; PIP="$VENV/pip3"; shift 2;;
+    -h|--help)        echo "$USAGE"; exit 0;;
+    *) echo "Unknown option: $1"; echo "$USAGE"; exit 1;;
+  esac
 done
 
-if ! ( type -P "$PYTHON" > /dev/null ) ; then
-	if [ "$PYTHON" == "python3" ]; then
-		printf "Fan SHIM controller requires Python 3\n"
-		printf "You should run: 'sudo apt install python3'\n"
-	else
-		printf "Cannot find virtual environment.\n"
-		printf "Set to base of virtual environment i.e. <venv>/bin/python3.\n"
-	fi
-	exit 1
+# Verify Python and pip
+echo "Checking Python environment..."
+if ! command -v "$PYTHON" >/dev/null 2>&1; then
+  echo "Python 3 not found. Installing..."
+  sudo apt install -y python3
 fi
 
-if ! ( type -P "$PIP" > /dev/null ) ; then
-	printf "Fan SHIM controller requires Python 3 pip\n"
-	if [ "$PIP" == "pip3" ]; then
-		printf "You should run: 'sudo apt install python3-pip'\n"
-	else
-		printf "Ensure that your virtual environment has pip3 installed.\n"
-	fi
-	exit 1
+if ! command -v "$PIP" >/dev/null 2>&1; then
+  echo "pip3 not found. Installing..."
+  sudo apt install -y python3-pip
 fi
 
-set -- "${POSITIONAL_ARGS[@]}"
-
-EXTRA_ARGS=""
-
-if [ "$PREEMPT" == "yes" ]; then
-	EXTRA_ARGS+=' --preempt'
-fi
-
-if [ "$NOLED" == "yes" ]; then
-	EXTRA_ARGS+=' --noled'
-fi
-
-if [ "$NOBUTTON" == "yes" ]; then
-	EXTRA_ARGS+=' --nobutton'
-fi
-
-if [ "$EXTCOLOURS" == "yes" ]; then
-	EXTRA_ARGS+=' --extended-colours'
-fi
-
-if ! [ "$1" == "" ]; then
-	if [ $ON_THRESHOLD_SET ]; then
-		printf "Refusing to overwrite explicitly set On Threshold ($ON_THRESHOLD) with positional argument!\n"
-		printf "Please double-check your arguments and use one or the other!\n"
-		exit 1
-	fi
-	ON_THRESHOLD=$1
-fi
-
-if ! [ "$2" == "" ]; then
-	if [ $OFF_THRESHOLD_SET ]; then
-		printf "Refusing to overwrite explicitly set Off Threshold ($OFF_THRESHOLD) with positional argument!\n"
-		printf "Please double-check your arguments and use one or the other!\n"
-		exit 1
-	fi
-	(( OFF_THRESHOLD = ON_THRESHOLD - $2 ))
-fi
-
-if [ "$LOW_TEMP" == "" ]; then
-    LOW_TEMP=$OFF_THRESHOLD
-fi
-
-if [ "$HIGH_TEMP" == "" ]; then
-    HIGH_TEMP=$ON_THRESHOLD
-fi
-
-cat << EOF
-Setting up with:
-Off Threshold:    $OFF_THRESHOLD C
-On Threshold:     $ON_THRESHOLD C
-Low Temp:         $LOW_TEMP C
-High Temp:        $HIGH_TEMP C
-Delay:            $DELAY seconds
-Preempt:          $PREEMPT
-Disable LED:      $NOLED
-Disable Button:   $NOBUTTON
-Brightness:       $BRIGHTNESS
-Extended Colours: $EXTCOLOURS
-
-To change these options, run:
-$USAGE
-
-Or edit: $SERVICE_PATH
-
+# Install dependencies
+echo "Installing required Debian packages..."
+sudo apt install -y python3-rpi.gpio python3-spidev python3-psutil python3-setuptools
+
+echo "Upgrading Python packages..."
+sudo "$PIP" install --upgrade psutil "rpi.gpio>=0.7.0" fanshim >/dev/null 2>&1 || true
+
+# Summary
+cat <<EOF
+
+Fan SHIM configuration
+----------------------
+Off Threshold:    ${OFF_THRESHOLD}°C
+On Threshold:     ${ON_THRESHOLD}°C
+Low Temp:         ${LOW_TEMP}°C
+High Temp:        ${HIGH_TEMP}°C
+Delay:            ${DELAY}s
+Preempt:          ${PREEMPT}
+Disable LED:      ${NOLED}
+Disable Button:   ${NOBUTTON}
+Brightness:       ${BRIGHTNESS}
+Extended Colours: ${EXTCOLOURS}
+Python:           ${PYTHON}
 
 EOF
 
-read -r -d '' UNIT_FILE << EOF
-[Unit]
-Description=Fan Shim Service
+# Generate systemd unit
+EXTRA_ARGS=""
+[[ "$PREEMPT" == "yes" ]] && EXTRA_ARGS+=" --preempt"
+[[ "$NOLED" == "yes" ]] && EXTRA_ARGS+=" --noled"
+[[ "$NOBUTTON" == "yes" ]] && EXTRA_ARGS+=" --nobutton"
+[[ "$EXTCOLOURS" == "yes" ]] && EXTRA_ARGS+=" --extended-colours"
+
+UNIT_FILE="[Unit]
+Description=Fan SHIM temperature controller
 After=multi-user.target
 
 [Service]
 Type=simple
-WorkingDirectory=$(pwd)
-ExecStart=$PYTHON $(pwd)/automatic.py --on-threshold $ON_THRESHOLD --off-threshold $OFF_THRESHOLD --low-temp $LOW_TEMP --high-temp $HIGH_TEMP --delay $DELAY --brightness $BRIGHTNESS $EXTRA_ARGS
+ExecStart=${PYTHON} $(pwd)/automatic.py \
+  --on-threshold ${ON_THRESHOLD} \
+  --off-threshold ${OFF_THRESHOLD} \
+  --low-temp ${LOW_TEMP} \
+  --high-temp ${HIGH_TEMP} \
+  --delay ${DELAY} \
+  --brightness ${BRIGHTNESS}${EXTRA_ARGS}
 Restart=on-failure
+WorkingDirectory=$(pwd)
 
 [Install]
 WantedBy=multi-user.target
-EOF
-
-printf "Checking for rpi.gpio >= 0.7.0 (for Pi 4 support)\n"
-$PYTHON - <<EOF
-import RPi.GPIO as GPIO
-from pkg_resources import parse_version
-import sys
-if parse_version(GPIO.VERSION) < parse_version('0.7.0'):
-    sys.exit(1)
-EOF
+"
 
-if [ $? -ne 0 ]; then
-	printf "Installing rpi.gpio\n"
-	$PIP install --upgrade "rpi.gpio>=0.7.0"
-else
-	printf "rpi.gpio >= 0.7.0 already installed\n"
-fi
-
-printf "Checking for Fan SHIM\n"
-$PYTHON - > /dev/null 2>&1 <<EOF
-import fanshim
-EOF
+echo "Installing systemd service to $SERVICE_PATH..."
+echo "$UNIT_FILE" | sudo tee "$SERVICE_PATH" >/dev/null
 
-if [ $? -ne 0 ]; then
-	printf "Installing Fan SHIM\n"
-	$PIP install fanshim
-else
-	printf "Fan SHIM already installed\n"
-fi
-
-printf "Checking for psutil >= $PSUTIL_MIN_VERSION\n"
-$PYTHON - > /dev/null 2>&1 <<EOF
-import sys
-import psutil
-from pkg_resources import parse_version
-sys.exit(not parse_version(psutil.__version__) >= parse_version('$PSUTIL_MIN_VERSION'))
-EOF
-
-if [ $? -ne 0 ]; then
-	printf "Installing psutil\n"
-	$PIP install --ignore-installed psutil
-else
-	printf "psutil >= $PSUTIL_MIN_VERSION already installed\n"
-fi
+sudo systemctl daemon-reload
+sudo systemctl enable pimoroni-fanshim.service
+sudo systemctl restart pimoroni-fanshim.service
 
-printf "\nInstalling service to: $SERVICE_PATH\n"
-echo "$UNIT_FILE" > $SERVICE_PATH
-systemctl daemon-reload
-systemctl enable --no-pager pimoroni-fanshim.service
-systemctl restart --no-pager pimoroni-fanshim.service
-systemctl status --no-pager pimoroni-fanshim.service
+echo "Installation complete."
+sudo systemctl status --no-pager pimoroni-fanshim.service
diff --git a/install.sh b/install.sh
index 11e66b9..d022004 100755
--- a/install.sh
+++ b/install.sh
@@ -1,131 +1,95 @@
-#!/bin/bash
+#!/usr/bin/env bash
+set -euo pipefail
 
-CONFIG=/boot/config.txt
-DATESTAMP=`date "+%Y-%m-%d-%H-%M-%S"`
+CONFIG="/boot/config.txt"
+DATESTAMP=$(date "+%Y-%m-%d-%H-%M-%S")
 CONFIG_BACKUP=false
-CODENAME=`lsb_release -sc`
-
-if [ $? -ne 0 ]; then
-	printf "Error parsing configuration...\n"
-	exit 1
-fi
+CODENAME=$(lsb_release -sc 2>/dev/null || echo "unknown")
 
 function do_config_backup {
-	if [ ! $CONFIG_BACKUP == true ]; then
-		CONFIG_BACKUP=true
-		FILENAME="config.preinstall-$LIBRARY_NAME-$DATESTAMP.txt"
-		printf "Backing up $CONFIG to $FILENAME\n"
-		cp $CONFIG $FILENAME
-	fi
+    if [ "$CONFIG_BACKUP" != true ] && [ -f "$CONFIG" ]; then
+        CONFIG_BACKUP=true
+        FILENAME="config.preinstall-${LIBRARY_NAME}-${DATESTAMP}.txt"
+        echo "Backing up $CONFIG to $FILENAME"
+        cp "$CONFIG" "$FILENAME"
+    fi
 }
 
 function apt_pkg_install {
-	PACKAGES=()
-	PACKAGES_IN=("$@")
-	for ((i = 0; i < ${#PACKAGES_IN[@]}; i++)); do
-		PACKAGE="${PACKAGES_IN[$i]}"
-		printf "Checking for $PACKAGE\n"
-		dpkg -L $PACKAGE > /dev/null 2>&1
-		if [ "$?" == "1" ]; then
-			PACKAGES+=("$PACKAGE")
-		fi
-	done
-	PACKAGES="${PACKAGES[@]}"
-	if ! [ "$PACKAGES" == "" ]; then
-		echo "Installing missing packages: $PACKAGES"
-		sudo apt update
-		sudo apt install -y $PACKAGES
-	fi
+    local missing=()
+    for pkg in "$@"; do
+        if ! dpkg -s "$pkg" >/dev/null 2>&1; then
+            missing+=("$pkg")
+        fi
+    done
+    if [ "${#missing[@]}" -gt 0 ]; then
+        echo "Installing missing packages: ${missing[*]}"
+        sudo apt update
+        sudo apt install -y "${missing[@]}"
+    fi
 }
 
-if [[ $CODENAME != "bullseye" ]]; then
-	apt_pkg_install python-configparser
-fi
+# Ensure python3 and pip3 exist
+apt_pkg_install python3 python3-pip python3-setuptools
 
-CONFIG_VARS=`python - <<EOF
+# Extract variables from setup.cfg using Python 3
+CONFIG_VARS=$(python3 - <<'EOF'
 from configparser import ConfigParser
-c = ConfigParser()
-c.read('library/setup.cfg')
-p = dict(c['pimoroni'])
-# Convert multi-line config entries into bash arrays
-for k in p.keys():
-    fmt = '"{}"'
-    if '\n' in p[k]:
-        p[k] = "'\n\t'".join(p[k].split('\n')[1:])
-        fmt = "('{}')"
-    p[k] = fmt.format(p[k])
-print("""
-LIBRARY_NAME="{name}"
-LIBRARY_VERSION="{version}"
-""".format(**c['metadata']))
-print("""
-PY3_DEPS={py3deps}
-PY2_DEPS={py2deps}
-SETUP_CMDS={commands}
-CONFIG_TXT={configtxt}
-""".format(**p))
-EOF`
-
-eval $CONFIG_VARS
-
-printf "$LIBRARY_NAME $LIBRARY_VERSION Python Library: Installer\n\n"
-
-if [ $(id -u) -ne 0 ]; then
-	printf "Script must be run as root. Try 'sudo ./install.sh'\n"
-	exit 1
-fi
-
-cd library
+from pathlib import Path
 
-if [[ $CODENAME != "bullseye" ]]; then
-	printf "Installing for Python 2..\n"
+cfg = Path("library/setup.cfg")
+if not cfg.exists():
+    raise SystemExit("Error: library/setup.cfg not found")
 
-	printf "Checking for rpi.gpio>=0.7.0 (for Pi 4 support)\n"
-	python - <<EOF
-import RPi.GPIO as GPIO
-from pkg_resources import parse_version
-import sys
-if parse_version(GPIO.VERSION) < parse_version('0.7.0'):
-    sys.exit(1)
+c = ConfigParser()
+c.read(cfg)
+p = dict(c["pimoroni"])
+meta = c["metadata"]
+
+def parse_multiline(val):
+    return [line.strip() for line in val.splitlines() if line.strip()]
+
+print(f'LIBRARY_NAME="{meta.get("name", "unknown")}"')
+print(f'LIBRARY_VERSION="{meta.get("version", "0.0.0")}"')
+print(f'PY3_DEPS=({" ".join(parse_multiline(p.get("py3deps", "")))})')
+print(f'SETUP_CMDS=({" ".join(parse_multiline(p.get("commands", "")))})')
+print(f'CONFIG_TXT=({" ".join(parse_multiline(p.get("configtxt", "")))})')
 EOF
+)
 
-	if [ $? -ne 0 ]; then
-		printf "Installing rpi.gpio\n"
-		pip install --upgrade "rpi.gpio>=0.7.0"
-	else
-		printf "rpi.gpio >= 0.7.0 already installed\n"
-	fi
+eval "$CONFIG_VARS"
 
-	apt_pkg_install "${PY2_DEPS[@]}"
-	python setup.py install
-fi
+echo "$LIBRARY_NAME $LIBRARY_VERSION Python Library: Installer"
+echo
 
-if [ -f "/usr/bin/python3" ]; then
-	printf "Installing for Python 3..\n"
-	apt_pkg_install "${PY3_DEPS[@]}"
-	python3 setup.py install
+if [ "$(id -u)" -ne 0 ]; then
+    echo "Script must be run as root. Try: sudo ./install.sh"
+    exit 1
 fi
 
+cd library
+
+echo "Installing for Python 3..."
+apt_pkg_install "${PY3_DEPS[@]}"
+python3 setup.py install
+
 cd ..
 
-for ((i = 0; i < ${#SETUP_CMDS[@]}; i++)); do
-	CMD="${SETUP_CMDS[$i]}"
-	# Attempt to catch anything that touches /boot/config.txt and trigger a backup
-	if [[ "$CMD" == *"raspi-config"* ]] || [[ "$CMD" == *"$CONFIG"* ]] || [[ "$CMD" == *"\$CONFIG"* ]]; then
-		do_config_backup
-	fi
-	eval $CMD
+for CMD in "${SETUP_CMDS[@]}"; do
+    if [[ "$CMD" == *"raspi-config"* ]] || [[ "$CMD" == *"$CONFIG"* ]]; then
+        do_config_backup
+    fi
+    eval "$CMD"
 done
 
-for ((i = 0; i < ${#CONFIG_TXT[@]}; i++)); do
-	CONFIG_LINE="${CONFIG_TXT[$i]}"
-	if ! [ "$CONFIG_LINE" == "" ]; then
-		do_config_backup
-		sed -i 's/^#$CONFIG_LINE/$CONFIG_LINE/' $CONFIG
-		if ! grep -q -E "^$CONFIG_LINE" $CONFIG; then
-			printf "$CONFIG_LINE\n" >> $CONFIG
-		fi
-	fi
+for LINE in "${CONFIG_TXT[@]}"; do
+    if [ -n "$LINE" ]; then
+        do_config_backup
+        if ! grep -q -E "^${LINE}" "$CONFIG" 2>/dev/null; then
+            echo "$LINE" >>"$CONFIG"
+            echo "Added: $LINE"
+        fi
+    fi
 done
 
-printf "Done!\n"
+echo "Done."