This controller is plug-and-play into hand sanitizer unit.
It is plugged-in into USB connector of the main board on one side and a wires from the dispenser plugged-in on the other side (white connector).
Once someone uses the sanitizer, the dispenser sends a signal to the controller and an event sent to the digital signage application. It can count the events, display a special content and produce usage reports.
Send request for quantities larger than a few units for discount.