Arduino-based liquid level sensing

January 30, 2017 // By Julien Happich
In order to address the vibrant and constantly expanding maker market, SST Sensing Ltd. has partnered up with Sparkfun to develop a simple to implement solution for single point liquid detection using infra-red technology.

The sensor board includes an Optomax Digital liquid level switch connected to an Arduino board via the TTL output and powered by its 5V source. LEDs on the Arduino can be easily programmed to indicate if the sensor is/isn’t immersed by the liquid (and thus determine if liquid level is too high/low). Using this hardware, hobbyists are provided with plenty of scope to experiment, while professional engineers have the opportunity to evaluate their prototype before moving on to a full scale design. The Optomax devices have compact dimensions that allow them to be deployed within environments where there is only limited available space. As relatively long cabling can be supported, the sensor can be placed in close proximity to a liquid without any risk of the accompanying electronics on the Arduino being damaged. The liquid level switch can be supplied by SST in a robust housing with either a Polysulfone or Trogamid construction. The complete solution has an operational temperature range that covers -25°C to +80°C. Visit Sparkfun at