Planet Arduino

A recent company move has left [kigster] and his 35 coworkers in a frustrating situation. Their new building only has two single occupancy bathrooms. To make matters worse, the bathrooms are located on two different floors. Heading to one bathroom, finding it occupied, then running upstairs to find the second bathroom also occupied became an all to common and frustrating occurrence at the office.

It was obvious the office needed some sort of bathroom occupancy monitoring system – much like those available on commercial aircraft. [kigster] asked for a budget of about $200 to build such a system. His request was quickly granted it by office management. They must have been on their way to the bathroom at the time.

[kigster] began work on BORAT: Bathroom Occupancy Remote Awareness Technology. The initial problem was detecting bathroom occupancy. The easiest method would be to use door locks with embedded switches, much those used in aircraft. Unfortunately, modifying or changing the locks in a rented office space is a big no-no. Several other human detection systems were suggested and rejected. The final solution was a hybrid. Sonar, Passive Infrared (PIR), and light sensors work in concert to detect if a person is in the bathroom. While we think the final “observer unit” is rather cool looking, we’re sure unsuspecting visitors to the office may be wondering why a two eyed robot is staring at them on the throne.

The display side of the system was easy. The entire system communicates with the venerable nRF24L01+ radio modules, so the display just needed a radio module, an arduino, and a way of displaying bathroom status. Two LED matrices took care of that issue.

We really like this hack. Not only is it a great use of technology to solve a common problem, but it’s also an open source system. BORAT’s source code is available on [kigster's] github.

Want to know more about BORAT? Kigster is answering questions over on his thread in the Arduino subreddit.