Makers, developers and enthusiasts building distance related projects may be interested to know that the HC-SR04 ultrasonic sonar distance sensor is now available to purchase directly from the ...

[ItMightBeWorse] is using readily available HC-SR04 sensor boards and has already done a proof-of-concept build. He’s getting real numbers back and getting close to a sensor that will go into an ...

With a standard old HC-SR04 ultrasonic sensor, an audio module and a servo to drive a custom gauge needle he’s made a device which can warn people around you if they’re too close for comfort.