The hero of our story practically lives in the pool during summertime. The all-wheel-drive robot, once started, runs around randomly in the pool for nearly a 3-hour cycle, while drawing water from the bottom through its 100 μm filter. Additionally, it can climb up to the waterline on demand and give it a slight scrub with its front rubber paddles.
Operating it is not rocket science; its console on the shore has only a start/stop button and another button to choose whether to clean just the bottom or the waterline as well. Unfortunately, as with many household electronics, this machine does not offer any remote control options. The task here would be simply for a machine to press the cleaning cycle start button in the morning and evening instead of a person.
Since the property already had the KNX architecture and we found a free relay, we could quickly solve the problem with minimal installation and some configuration.
The robot's warranty had expired, so we could open its controller and lead out a connector wired in parallel with the push button. We connected this to a free relay of a KNX switch actuator, and then configured the relay in the actuator so that activating it would trigger a one-second staircase function. In this case, the relay would pull in due to the activating telegram, and after one second, it would release - just like when a person presses a button.
From this point on, we only needed a timer to send the two telegrams in the morning and evening, and the robot finally does its job without human intervention. Now, the robot is a bit more robotic.