This repository contains a Python project (for Raspberry) that uses an HCSR04 sensor to detect the presence of a person in front of a fixed background (e.g. wall or floor) and dynamically plays or pauses a video accordingly.
/media video folder
/src
/main.py main code
/hcsr04.py hcsr04 sensor class (HCSR04)
/media_player.py media player class (MediaPlayer)
requirements.txt dependencies
The project is implemented on a Raspberry Pi 5 8GB, accompanied by an HCSR04 sensor for distance detection. For a detailed schematic diagram illustrating the connection between the Raspberry Pi and the HCSR04 sensor, please refer to the GPIO Zero documentation.
No external resistors were used in my setup. The sensor was successfully powered at 3.3V, and it exhibited precise functionality comparable to its performance when powered by 5V.
| Sensor | Pin |
|---|---|
| GND | GND |
| VCC | 3V3 |
| TRIG | GPIO23 (16) |
| ECHO | GPIO24 (18) |
For optimal performance on Raspberry Pi 5, using the H.265 (HEVC) codec for MP4 video files significantly improves playback efficiency and overall video processing (because Raspberry Pi 5 has a 4Kp60 HEVC decoder).
Due to potential sensor errors, the program transitions between states (from human_detected to human_not_detected or vice versa) only when the new state is stable.
A state is stable iff at least a certain percentage (STABILITY_THRESHOLD) of states are of the same type among the last n (STABILITY_WINDOW_SIZE) states received.
- HCSR04: gpiozero
- MediaPlayer: python-vlc
- gpiozero optimization
- handle exceptions
- video KeyboardInterrupt