An electronic device is located in a room. The device has a casing, a first processor coupled to a radar transceiver, a second processor coupled to a motion sensor, and memory. Using the second processor, the device determines using signals from the motion sensor whether an object is in proximity. In accordance with a determination that the object is in proximity, the device wakes up the first processor. Using the first processor, the device enables operation of the radar transceiver. It determines using signals from the radar transceiver whether the object is in contact with the casing. In accordance with a determination that the object is in contact with the casing, the device identifies an input command based on at least one of: a location of the object, and a movement of the object, and adjusts operation based on the input command.