Summary

This is a 3D printed case (two parts: body + lid) designed for a DIY motion sensor based on ESPHome and Home Assistant.

Features:

• 3D printed enclosure with body and removable lid
• Powered via USB-C (no batteries required)
• Direct integration into Home Assistant via ESPHome
• Compact and easy to assemble

This design is intended for makers who want a simple, reliable motion sensor for smart home automation (e.g. lights, presence detection, security).

Assembly

• Print out the body and cover
• Install ESPHome on the Esp using the .yaml file.
• Make sure that ESPHome has been installed correctly and then remove the pins by soldering. Updates can then only be transferred wirelessly.
• Apply 5V to the areas marked IN+ / IN- and measure OUT+ / OUT- with a multimeter. Adjust the DC-DC converter by turning the screw until it shows 3.3V. Optionally, a drop of glue can be applied to the screw to prevent it from moving.
• Wire the parts according to the diagram.

circuit diagram

• Ensure that the electrical components do not make unwanted contact when installed by using masking tape.
• Screw the PIR sensor into the screw holes provided using two small screws.  
• The PIR sensor can be adjusted by turning the potentiometers in the range and delay.

Electronics

• HC-SR501 PIR motion sensor [https://de.aliexpress.com/item/1005008748087679.html](https://de.aliexpress.com/item/1005008748087679.html)
• ESP8266-01S (runs ESPHome) [https://de.aliexpress.com/item/1005004626018608.html](https://de.aliexpress.com/item/1005004626018608.html)
• USB-C connector (power supply only, no battery) [https://de.aliexpress.com/item/1005007345400483.html](https://de.aliexpress.com/item/1005007345400483.html)
• DSN-Mini360 DC-DC converter [https://de.aliexpress.com/item/1005007052658378.html](https://de.aliexpress.com/item/1005007052658378.html)