Initial commit: Paperwall, a standalone e-ink dashboard

Navidrome now-playing, clock, and weather for a Waveshare epd4in0e panel,
with a local web UI and install/uninstall scripts for the Pi.

install.sh

@@ -0,0 +1,123 @@
+#!/bin/bash
+# Installs Paperwall on this machine, in place. Standalone -- doesn't require
+# InkyPi to be installed. If InkyPi (or anything else) happens to already be
+# running against the same panel, this stops it, since two processes can't
+# both drive the same SPI display.
+#
+# Run this ON the Pi, from wherever you copied the project folder to (e.g.
+# via SFTP): `sudo bash install.sh`
+
+set -euo pipefail
+
+# Resolve the real directory this script lives in, even through symlinks.
+SOURCE="${BASH_SOURCE[0]}"
+while [ -h "$SOURCE" ]; do
+  DIR=$(cd -P "$(dirname "$SOURCE")" >/dev/null 2>&1 && pwd)
+  SOURCE=$(readlink "$SOURCE")
+  [[ $SOURCE != /* ]] && SOURCE="$DIR/$SOURCE"
+done
+APP_DIR=$(cd -P "$(dirname "$SOURCE")" >/dev/null 2>&1 && pwd)
+
+VENV_DIR="$APP_DIR/venv"
+SERVICE_NAME="paperwall.service"
+SERVICE_TARGET="/etc/systemd/system/$SERVICE_NAME"
+CONFIG_TXT="/boot/firmware/config.txt"
+[ -f "$CONFIG_TXT" ] || CONFIG_TXT="/boot/config.txt"
+
+step() { echo -e "\n==> $1"; }
+
+check_permissions() {
+  if [ "$EUID" -ne 0 ]; then
+    echo "ERROR: run with sudo (sudo bash install.sh)" >&2
+    exit 1
+  fi
+}
+
+install_system_dependencies() {
+  step "Installing system dependencies (python3-venv, lgpio/spidev build deps)"
+  apt-get update -qq
+  apt-get install -y -qq python3-venv python3-pip python3-dev liblgpio-dev swig
+}
+
+enable_spi_i2c() {
+  step "Enabling SPI/I2C in $CONFIG_TXT"
+  if [ ! -f "$CONFIG_TXT" ]; then
+    echo "  WARNING: $CONFIG_TXT not found -- enable SPI/I2C manually for your platform." >&2
+    return
+  fi
+
+  if grep -qE '^\s*dtparam=spi=on' "$CONFIG_TXT"; then
+    echo "  SPI already enabled."
+  else
+    sed -i -E 's/^#?\s*dtparam=spi=.*/dtparam=spi=on/' "$CONFIG_TXT"
+    grep -qE '^\s*dtparam=spi=on' "$CONFIG_TXT" || echo "dtparam=spi=on" >> "$CONFIG_TXT"
+    echo "  SPI enabled (reboot required)."
+  fi
+
+  # This panel uses both SPI chip-select lines.
+  if ! grep -qE '^\s*dtoverlay=spi0-2cs' "$CONFIG_TXT"; then
+    echo "dtoverlay=spi0-2cs" >> "$CONFIG_TXT"
+    echo "  Added dtoverlay=spi0-2cs (reboot required)."
+  fi
+
+  if grep -qE '^\s*dtparam=i2c_arm=on' "$CONFIG_TXT"; then
+    echo "  I2C already enabled."
+  else
+    sed -i -E 's/^#?\s*dtparam=i2c_arm=.*/dtparam=i2c_arm=on/' "$CONFIG_TXT"
+    grep -qE '^\s*dtparam=i2c_arm=on' "$CONFIG_TXT" || echo "dtparam=i2c_arm=on" >> "$CONFIG_TXT"
+    echo "  I2C enabled (reboot required)."
+  fi
+}
+
+create_venv() {
+  step "Creating Python virtual environment at $VENV_DIR"
+  python3 -m venv "$VENV_DIR"
+  "$VENV_DIR/bin/python" -m pip install --upgrade -q pip
+  "$VENV_DIR/bin/python" -m pip install -q -r "$APP_DIR/requirements.txt" -r "$APP_DIR/requirements-pi.txt"
+  echo "  done."
+}
+
+stop_conflicting_services() {
+  step "Checking for other software already driving this panel"
+  if systemctl list-unit-files inkypi.service >/dev/null 2>&1 && systemctl is-active --quiet inkypi.service; then
+    systemctl disable --now inkypi.service
+    echo "  Stopped and disabled inkypi.service (left installed, not removed)."
+  else
+    echo "  Nothing else running against the panel."
+  fi
+}
+
+install_service() {
+  step "Installing $SERVICE_NAME"
+  sed \
+    -e "s#{{APP_DIR}}#$APP_DIR#g" \
+    -e "s#{{PYTHON}}#$VENV_DIR/bin/python3#g" \
+    "$APP_DIR/paperwall.service.template" > "$SERVICE_TARGET"
+  systemctl daemon-reload
+  systemctl enable --now "$SERVICE_NAME"
+  echo "  installed and started."
+}
+
+show_status() {
+  step "Status"
+  sleep 2
+  systemctl status "$SERVICE_NAME" --no-pager -l | head -15 || true
+  ip_address=$(hostname -I | awk '{print $1}')
+  echo
+  echo "Web UI: http://$ip_address:8080  (or http://$(hostname).local:8080)"
+  echo "Logs:   journalctl -u $SERVICE_NAME -f"
+  echo "Remove: sudo bash uninstall.sh"
+  if grep -qE '^\s*dtoverlay=spi0-2cs' "$CONFIG_TXT" 2>/dev/null; then
+    echo
+    echo "NOTE: if SPI/I2C were just newly enabled above, reboot for that to take effect:"
+    echo "      sudo reboot"
+  fi
+}
+
+check_permissions
+install_system_dependencies
+enable_spi_i2c
+create_venv
+stop_conflicting_services
+install_service
+show_status