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How to use an HC-SR04 ultrasonic sensor for accurate distance measurement
The HC-SR04 is the cheapest reliable way to measure distance with a microcontroller. It works by emitting a 40kHz ping and timing the echo's return. Effective range: about 2cm to 4m, with ±3mm accuracy in the sweet spot. Parts: • HC-SR04 ultrasonic module • Arduino UNO/Nano • 4…
