Want to extend your Altstec setup without buying another sensor? Our DIY Motion Sensor Kit (and open-source firmware) lets advanced users build a fully compatible motion sensor for under $20 in parts. This guide covers everything from the parts list to pairing it with the app.
1. Components You'll Need
- 1x ESP8266 or ESP32 microcontroller board
- 1x PIR motion sensor module (HC-SR501 or similar)
- 1x USB power supply or battery pack
- Jumper wires and a small breadboard or enclosure
- The Altstec DIY firmware (available with the DIY Motion Sensor Kit)
2. Wiring the Circuit
Connect the PIR sensor's VCC pin to the microcontroller's 3.3V or 5V output
(depending on your sensor's spec), GND to ground, and the OUT pin to a
digital GPIO pin (we recommend GPIO 14). Double-check polarity before powering on — reversed
power connections are the most common cause of a "dead" sensor.
3. Flashing the Firmware
- Download the Altstec DIY firmware package from the kit's included instructions.
- Connect your microcontroller to your computer via USB.
- Flash the firmware using the provided flashing tool, selecting the correct board and port.
- On first boot, the device creates a temporary WiFi network for setup.
4. Connecting to the Altstec App
- In the app, go to Add Device → DIY Sensor.
- Connect your phone to the sensor's temporary setup network when prompted.
- Enter your home WiFi credentials so the sensor can connect permanently.
- Name the sensor and assign it to a room — it will now appear alongside your other motion sensors and trigger the same alert flows.
5. Mounting & Calibration Tips
- Mount 6–8 feet high, angled downward, for the widest detection cone.
- Most PIR modules have onboard potentiometers for sensitivity and trigger duration — start with mid-range settings and adjust based on false alerts.
- Keep the sensor away from heating vents and direct sunlight, both of which can cause false triggers.
Pair your new DIY sensor with a camera for visual confirmation — see our guide on setting up your first security camera, or browse the pre-built Advanced Motion Sensor if you'd rather skip the soldering.