With inexpensive ultrasonic sensors, you can design both basic and sophisticated measuring devices for various ranging applications. By combining one of these modules with a display, a few press buttons, and an ATmega8 microcontroller, you can easily assemble a handy level and range circuit. Check out this 2014 design to build your own distance and level gauge!

Distance and Level Gauge Circuit

Refer to the distance and level gauge circuit, which measures liquid levels and distances. The ATmega8-16PU-based design delivers the following features: a watchdog function monitors fill level, with relay output and alarm LED; you can program min/max alarm levels; it can store min/max calibration values for up to 10 tanks or containers in memory; and it has an intuitive menu.
distance and level gauge circuit
Simplified circuit of the distance and level gauge
“Once the programmed ATmega8 has been inserted and the ultrasonic modules connected, you can switch on the device for the first time,” Jörg Trautmann explained. “At very least, the background lighting for the LCD should illuminate. If this is not the case, disconnect the power supply and double-check the component placing! During the start phase, “Distance & Level Gauge 2.4” should be visible on the display for two seconds. Now you can perform the basic settings.”
distance and level gauge design
The project

The Program

The microcontroller’s program covers the following functions:
  • Indication of the level of liquids
  • Watchdog monitoring of this level with relay output and LED alert
  • Infinitely variable programming of the min/max alarm level
  • Storage of min/max calibration values for up to 10 containers or tanks
  • Distance measurement
  • Intuitive menu guidance using LCD readout
  • Offset correction for distance measurement
  • Manual divisor correction to accommodate low and high temperature extremes

The complete article will be freely available for the next three weeks. Enjoy!

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