This is an Arduino-based Proximity Sensor circuit wired using the popular HC-SR04 Ultrasonic ranging module,used here for non-contact object detection purpose. The HC-SR04 module includes ultrasonic ...

Inside the 3D printed enclosure is an Arduino Pro Mini, a HC-SR04 ultrasonic sensor, and a 1602 serial LCD. ... there’s one key component that gives it an extra bit of polish.

[Mike] lives in a temperate rainforest in Alaska (we figured from his website’s name) and uses a 570 gallon oil tank to supply his furnace. Until now, he had no way of knowing how much oil wa… ...