A custom 3D-printed alarm panel based on ESPHome, designed for Home Assistant integration
Features • Hardware • Installation • Usage • Acknowledgments • License
This project provides a complete solution for a custom alarm panel that integrates seamlessly with Home Assistant. After searching for commercial options and finding them either cloud-dependent, limited, or expensive, this open-source alternative I designed using ESPHome and 3D printing.
The panel combines RFID authentication with visual and audible feedback, featuring a clean, modern design inspired by contemporary smart home aesthetics.
To take full advantage, it is recommended to use it with Home Assistant Manual Alarm control panel integration.
- RFID Authentication: Secure arm/disarm using RFID badges
- Visual Feedback: 1.54" OLED display with custom animations and countdown timers
- LED Indicators: WS2812B LED strip for color-coded status indication
- Audible Alerts: Active buzzer for confirmation beeps
- Home Assistant Integration: Native ESPHome integration with event triggers
- Fully Customizable: Open-source design allows complete customization
- Offline Operation: No cloud dependency required
The alarm panel can be in four modes:
| Panel Mode | Corresponding Alarm state | Display state | LED strip state | Buzzer state |
|---|---|---|---|---|
| Standby | Disabled | Time of the day | Turned off | Turned off |
| Arming | Will be armed in 30sec | 30sec countdown | Orange | Turned off |
| Waiting | Will be triggered in 30sec | Waiting character animation | Orange | Turned off |
| Alert | Triggered, intrusion! | Angry character animation | Blinking red | ON every sec |
It also gives feedback in case a tag is scanned:
| Tag | Display state | LED strip state | Buzzer state |
|---|---|---|---|
| Valid | Happy character animation | Green | Two short beeps |
| Wrong | Sad character animation | Red | One long beep |
| Component | Description | Link |
|---|---|---|
| ESP32-S2 Mini | Microcontroller board | https://fr.aliexpress.com/item/1005006246777213.html |
| CH1116 OLED | 1.54" display | https://fr.aliexpress.com/item/1005009132302307.html |
| MFRC-522 | RFID reader | https://fr.aliexpress.com/item/1005006087459353.html |
| Active Buzzer | 5V 12x9.5mm | https://fr.aliexpress.com/item/1005007143315059.html |
| WS2812B LED Strip | 144 LED/m (8 LEDs section) | https://fr.aliexpress.com/item/1005007982624217.html |
| RFID Tags | 13.56 MHz keyfob tags (S50) | https://fr.aliexpress.com/item/1005005715485875.html |
| 24 AWG Wires | For internal wiring | https://fr.aliexpress.com/item/1005007391168450.html |
| M3 Screws | 8mm torx (5 pcs) | https://fr.aliexpress.com/item/4000222500869.html |
| PLA Filament | Matte white recommended | https://www.amazon.fr/dp/B0D4Z8QT5T |
Total Cost: Approximately €40–50 (excluding 3D printer)
The enclosure consists of two parts:
- Backplate: Houses all components with integrated cable channels
- Faceplate: Cover with stylized buzzer grille
Print both 3D parts using the provided STL files available in the hardware/3d-models/ directory.
Print Settings:
- Layer height: 0.2 mm
- Infill: 20%
- Support: Not required
- Material: PLA (white recommended)
NB: In case you want to make your own version of the model, Fusion 360 project file is also available in the hardware/3d-models/ directory.
Next step is to solder components according to the wiring diagram.
Detailed wiring diagrams are available in the hardware/wiring/ directory. Below is a summary of connections:
Click to expand wiring table
CH1116 OLED Screen → ESP32-S2 Mini
| Screen | ESP32 | Protocol |
|---|---|---|
| SDA | GPIO 8 | I2C Data |
| SCL | GPIO 10 | I2C Clock |
| GND | GND | Ground |
| VCC | 5V | Power |
MFRC522 RFID Reader → ESP32-S2 Mini
| RFID | ESP32 | Protocol |
|---|---|---|
| SDA | GPIO 12 | SPI CS |
| SCK | GPIO 7 | SPI Clock |
| MOSI | GPIO 11 | SPI MOSI |
| MISO | GPIO 9 | SPI MISO |
| RST | GPIO 21 | Reset |
| GND | GND | Ground |
| 3V3 | 3V3 | Power |
Active Buzzer → ESP32-S2 Mini
| Buzzer | ESP32 | Type |
|---|---|---|
| GND | GND | Ground |
| VCC | GPIO 16 | Control |
WS2812B LED Strip → ESP32-S2 Mini
| LED | ESP32 | Type |
|---|---|---|
| DATA | GPIO 37 | Data |
| VCC | VBUS | 5V Power |
| GND | GND | Ground |
ℹ️ To fit everything in the case, it is recommended to solder the wires on both sides of the ESP32 S2 Mini.
Once everything is soldered, route wires through integrated cable channels and secure components to the backplate.
Optional: To prevent light bleeding, you can add opaque stickers inside the case.
Installation step before attaching the faceplate using 5× M3 screws.
In fact, to flash the Lolin S2 Mini for the first time via USB, it is required to access O and RST buttons.
- A running Home Assistant instance
- ESPHome installed
- Either as a standalone CLI install
- Or as the ESPHome Home Assistant Add-on on Home Assistant OS setup
- USB cable for initial flashing of ESP32-S2 Mini
-
Clone this repository:
git clone https://github.com/fbertet/alarm-panel.git cd alarm-panel -
Configure secrets (Wi-Fi + ESPHome credentials):
In the
esphome/directory, create your secrets file from the example:cd esphome cp secrets.yaml.example secrets.yamlEdit
secrets.yamlwith your actual values:wifi_ssid: Your Wi-Fi AP SSIDwifi_password: Your Wi-Fi AP passwordalarm_panel_api_encryption_key: A 32-byte base64-encoded encryption key for ESPHome API (see documentation)alarm_panel_ota_password: Password that will be required for over-the-air updatesalarm_panel_fallback_ap_password: Password that will be required to connect to fallback captive portal
-
Configure device IP
Edit
alarm-paneland set a static IP address so OTA works reliably (configure static DHCP reservation on your router):wifi: ssid: !secret wifi_ssid password: !secret wifi_password # FIXME Replace this by your ESP32 fixed IP address: use_address: 192.168.1.X
-
First flash (USB required):
From the
esphome/directory:esphome run alarm-panel.yaml
On the Lolin S2 Mini, hold the
Obutton while pressingRSTto enter the bootloader mode on first flash. -
Find your RFID Tag UIDs and configure them in
alarm-panel.yamlOnce the device is flashed, you're ready to configure it with your own RFID tags.
To know their UIDs:
- Connect to the device logs:
esphome logs alarm-panel.yaml
- Present your tags to the RFID reader
- Note the UID strings shown in the logs (example:
7B-D3-A1-15) - Update the
valid_tagsglobal inalarm-panel.yamlreplacingTAG_UID_1, etc. by your values:globals: - id: valid_tags type: std::vector<std::string> initial_value: '{"TAG_UID_1", "TAG_UID_2"}'
You can add more than two tags if needed.
Reflash (OTA or USB) after changing the YAML.
- Connect to the device logs:
-
Subsequent updates (OTA):
Once the device is on Wi-Fi and reachable at its configured IP:
esphome run alarm-panel.yaml --device <YOUR_DEVICE_IP_ADDRESS>
- The device should be auto-discovered in Home Assistant via the ESPHome integration
- Add the device to Home Assistant and ensure entities are available
- Create automations to:
- Set the panel mode based on your alarm state
- React to valid/invalid tag events (arm/disarm, entry/exit logic, etc.)
- CH1116 Display: The first two columns may show noise due to ESPHome compatibility issues. This is cosmetically addressed in the code by mirroring a similar effect on the opposite side of the screen.
- Light Bleeding: Use opaque stickers inside the case or consider multi-material printing (with a thin inner black layer) if your printer supports it.
- Add fingerprint sensor support
- Add keypad support
- Improve CH1116 driver compatibility
- Special thanks to Valeria for help on this project
- Shout-out to ESPHome contributors, this tool makes it easy to bring projects like this to life
- Inspired by this YouTube video: https://youtu.be/qzofMR-WtJw?si=PYulEtwfABFObON4&t=1020
This project is licensed under the MIT License – see the LICENSE file for details.
- Blog Post: https://francois.bertet.dev/projects/alarm
- ESPHome: https://esphome.io/
- Home Assistant: https://www.home-assistant.io/
Made with ❤️ for the Home Assistant community
If this project helped you, consider starring ⭐ the repository!