You can choose between the one or two pin approach with the HY-SRF05 Ultrasonic sensors which cost roughly the same as the HC-SR04, so it seems a little odd to hack the SR04 instead of picking up ...

Specifications of the ultrasonic sonar distance sensor that can be used with Arduino, Raspberry Pi, CircuitPython and more include : – Power & Logic Voltage: DC 5V – Current during measurment ...

Inside [Klaus]’ device is an Arduino Uno, an HC-SR04 ultrasonic distance sensor, ... Buy arduino, buy sound shield, buy distance sensor shield, plug into each other, ...

In this mode, you can interface the HC-SR04 ultrasonic ping sensor with a servo motor and the main board (Only some reward tiers include the extra servo motor PCB and servo motor kit).