Pool Monitor | Smart Swimmingpool

The Pool Monitor is a compact E-Ink display device that shows current pool data by subscribing to Home Assistant MQTT topics from the Pool Controller:

• Pool water temperature
• Solar storage temperature
• Pool pump status (on/off)
• Solar heating status (on/off)

All data is read-only — the monitor displays what the pool controller publishes. No sensors, relays, or wiring required. Just power via USB-C and configure WiFi + MQTT through the captive portal.

Features

• WiFi configuration via captive portal (ESP-WiFiSettings)
• MQTT connection to existing pool controller
• Reads Home Assistant MQTT state topics
• NTP time synchronisation with automatic CET/CEST
• Deep-sleep operation (180 s cycle, ~5.5 mA average)
• Solar-powered operation (documented in Hardware Guide)
• OTA firmware updates via GitHub Releases
• System monitoring with watchdog and memory checks
• Boot-loop detection for reliable operation
• Configuration portal with QR code on MQTT errors

Planned Features

• Support for additional display sizes
• Ability to switch solar heating on/off (requires interactive mode)
• Ability to switch pool pump on/off (requires interactive mode)
• Web dashboard (served from ESP32 during configuration mode)

Guides

• Users Guide — Setup, configuration, display layout
• Hardware Guide — Board variants, pinout, solar powering
• Software Guide — Development, build, MQTT topics

Architecture

The firmware follows the same patterns as the Pool Controller for consistency:

• PoolMonitorContext — main singleton that owns all subsystems
• SystemMonitor — watchdog, memory monitoring, boot-loop detection
• NetworkManager — WiFi and MQTT connection management
• DisplayManager — E-Ink display control
• OtaUpdater — OTA firmware update checker and installer
• TimeClientHelper — NTP time sync and timezone support

Key design principles: RAII resource management, static method access for subsystems, dependency injection via Preferences handles, stack-allocated buffers for memory safety, and graceful degradation on errors.

Quality Checks

Run the local quality gates before pushing changes:

• Install Python-based linters once: python3 -m pip install --user cpplint yamllint
• markdownlint-cli2 and jscpd are executed on demand via npx
• make lint runs Super-Linter via Docker (see CONTRIBUTING.md)
• Stage your changes first, then run:

platformio check --environment LILYGO_T5_V231 --skip-packages
platformio run --environment LILYGO_T5_V231
mapfile -t cpp_files < <(git diff --cached --name-only -- '*.cpp' '*.hpp' '*.h')
((${#cpp_files[@]})) && cpplint "${cpp_files[@]}"
mapfile -t md_files < <(git diff --cached --name-only -- '*.md')
((${#md_files[@]})) && npx --yes markdownlint-cli2 "${md_files[@]}"
mapfile -t yaml_files < <(git diff --cached --name-only -- '*.yml' '*.yaml')
((${#yaml_files[@]})) && yamllint "${yaml_files[@]}"
npx --yes jscpd --config .jscpd.json src .github/workflows
python -m json.tool .jscpd.json > /dev/null

Discussions

See GitHub Discussions.

License

MIT