Washrooms are one of the highest-maintenance rooms in companies, but checking soap, cotton towel and toilet paper dispensers will be easier in the future, thanks to a system of sensors and some ingenious wireless technology.

The Fraunhofer Institute for Integrated Circuits IIS has designed a system that notifies cleaning staff when the dispensers' levels are running low, allowing them to plan their rounds far more effectively.

Based on sensors, the battery-operated CWS Washroom Information Service system, developed by Fraunhofer IIS and CWS-boco International GmbH, monitors the fill levels of soap dispensers, cotton towel rolls and toilet paper. The measurement method employed depends on the task. For instance, in the case of the soap dispenser, an optical sensor keeps an eye on the fill level and the sensor module gathers the data from the meter in the soap dispenser that records every portion dispensed. Optical systems are also used for toilet paper, while a portion meter monitors the usage of the cotton towel dispenser.

The data collected is sent through a wireless transmission system. First, the dispenser information is transmitted to the nearest “Washroom Control Unit” (WCU) via energy-saving Bluetooth 4.0 Low Energy. Each WCU is a collection point and communication node. They are distributed around the entire building and networked with each other via Fraunhofer's s-net wireless technology, which allows the wireless network to configure itself. Each WCU in the network decides autonomously what device it sends the data to.

“If a given module is out of order or cannot be reached for other reasons, the WCU sends its data to another module,” said Fraunhofer expert Wieland. This means the wireless network compensates automatically for a defective device or any disturbances in the transmission path. Once all the data has been collected, the final WCU in the transmission chain sends the entire data package—again via s-net—to a gateway, which is generally attached to the outside of the building.

From there, the information is then forwarded via the cellular network to CWS-boco’s server. A visual user interface displays the information for each individual washroom operator. The shift supervisor can then print out the washroom information as a shift plan or send it to the cleaning staff’s tablets. Another option would be to have a display at the entrance to the washrooms that shows what the washroom requires.

With the development phase of the “CWS Washroom Information Service” now more or less completed, a progressive field trial with a pilot customer is beginning in the first quarter of 2017, according to Fraunhofer.

CWS-boco will market the system, but Fraunhofer researchers aren’t only thinking about washroom services. “The system is ideal for any situation where sensor data has to be gathered and transmitted,” Wieland said.