![raspberry pi - Connecting NPN proximity sensor to rpi3 using reed relay - Electrical Engineering Stack Exchange raspberry pi - Connecting NPN proximity sensor to rpi3 using reed relay - Electrical Engineering Stack Exchange](https://i.stack.imgur.com/V2LNm.png)
raspberry pi - Connecting NPN proximity sensor to rpi3 using reed relay - Electrical Engineering Stack Exchange
![GitHub - solacese/raspberry-pi-ultrasonic-sensor-mqtt: A demo app that integrates an HCSR04 proximity sensor on a Raspberry PI with an MQTT publisher GitHub - solacese/raspberry-pi-ultrasonic-sensor-mqtt: A demo app that integrates an HCSR04 proximity sensor on a Raspberry PI with an MQTT publisher](https://raw.githubusercontent.com/fivdi/pi-io/master/doc/hc-sr04-two-pin.png)
GitHub - solacese/raspberry-pi-ultrasonic-sensor-mqtt: A demo app that integrates an HCSR04 proximity sensor on a Raspberry PI with an MQTT publisher
![QUESTION: Triggering video using HC-SR04 distance sensor on RPI 4 - Processing for Pi - Processing Foundation QUESTION: Triggering video using HC-SR04 distance sensor on RPI 4 - Processing for Pi - Processing Foundation](https://global.discourse-cdn.com/standard10/uploads/processingfoundation1/optimized/2X/1/181649b7131520d6b0e8ccd45713c138fbf1c63c_2_534x500.gif)
QUESTION: Triggering video using HC-SR04 distance sensor on RPI 4 - Processing for Pi - Processing Foundation
![Using an ultrasonic distance sensor | Physical Computing with Python | Python | Coding projects for kids and teens Using an ultrasonic distance sensor | Physical Computing with Python | Python | Coding projects for kids and teens](https://projects-static.raspberrypi.org/projects/physical-computing/248971027a596f3437da45bafd2bd8a8cc35cb95/en/images/wiring-uds.png)