At this point, note that Mode 1 (Default Mode) uses the echo & trigger pins like a standard ultrasonic sensor whereas Mode 2 (TTL Serial Output Mode) uses software serial. So, if you wish to use Mode ...

The HC-SR04 ultrasonic range sensor is a pretty cool pre-wired module that you actually enjoy using when you start playing with electronics, microcontrollers, and robotics. As you might have noticed, ...

The sensors attached to the Arduino had an approximate scanning range of 3m, and the ultrasonic units were modified to broadcast an analog signal at 40 kHz.

One way to accomplish this involves four HC-SR04 ultrasonic sensor units that transmit data through an Arduino into a Linux computer. The end result is a virtual touchscreen that can be made at home.