Gigantic Ultrasonic Sensor

HC-SR04 ultrasonic sensors are employed in a wide range of robotics projects, allowing distance measurement or presence sensing. These devices feature a small rectangular PCB form factor, with transmitter and receiver “cans” soldered on facing in the same direction.

But why this particular form factor? Could it perhaps be smaller, or larger even? As outlined here, and in the video below, YouTuber CrazyScience was able to turn an HC-SR04 sensor into something much bigger. Although he doesn’t have a direct answer for why he did this, he notes that “applying creativity in a unique way is a very good thing.” That seems like a good enough reason, as he no doubt learned something along the way.

The electronics part of the build involved desoldering the sensor cans, then reattaching them with 15 cm wires, e them to be repositioned as needed. From there he created a replica of the sensor, using water bottles, aluminum foil, and steel mesh to replicate the sensor cylinder cans. Cardboard was used to form the PCB base and faux connector pins.

The smaller desoldered cans were then attached to holes in the center of the giganto-cans' mesh, and the actual HC-SC04 PCB was attached to the cardboard. While the spacing is much different than before, the device appears to work quite well in a presence-detection mode, using an Arduino Nano to actuate a small servo based on this input.