Pretty cool project by Gus via PiMyLifeUp:
We will be showing you how to wire the HC-SR04 sensor up to the Raspberry Pi, including how to wire a voltage divider as the circuit requires one to drop the 5v output from the sensor to 3.3v for the Raspberry Pi. This is just one of many sensors you can use with your Raspberry Pi, if you’re interested in more, then be sure to check out our Raspberry Pi sensor tutorials section.
Including showing how to wire up the sensor to the Raspberry Pi, we also explore writing a Python script that will utilize the HC-SR04 Ultrasonic sensor to calculate distance. We achieve this by measuring the time it takes the ultrasonic pulse being sent out to it being received back by the sensor.
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