Capacitive proximity sensing

A proximity sensing apparatus comprising:

• means for processing an output signal received from a proximity sensing capacitor, the output signal generated by the proximity sensing capacitor based on a reference signal, the output signal indicative of an object proximate to the proximity sensing capacitor, the capacitor including:
• a ground plane;
• and
• an electrode substantially coplanar with and capacitively coupled to the ground plane, the electrode and ground plane to form an electric field in response to the input signal;
• and
• means for detecting an object within the electric field based on a change in the output signal;
• wherein:
• the output signal has a first frequency associated with the object interacting with the electric field;
• the output signal has a second frequency associated with the object not interacting with the electric field;
• and
• the detection of the object is based on detecting a difference between the first frequency and the second frequency.

A proximity sensing apparatus comprising:

• a proximity sensing capacitor to generate an output signal indicative of an object proximate to the sensing apparatus based on a reference signal, the capacitor including:
• a ground plane;
• and
• an electrode substantially coplanar with and capacitively coupled to the ground plane, the electrode and ground plane to form an electric field in response to the input signal;
• and
• controller circuitry electrically coupled to the proximity sensing capacitor, the controller circuitry to detect an object within the electric field based on a change in the output signal;
• wherein:
• the output signal has a first frequency associated with the object interacting with the electric field;
• the output signal has a second frequency associated with the object not interacting with the electric field;
• and
• the detection of the object is based on detecting a difference between the first frequency and the second frequency.

A home automation apparatus comprising:

• a proximity sensing apparatus including:
• a proximity sensing capacitor to generate an output signal indicative of an object proximate to the sensing apparatus based on a reference signal, the capacitor including:
• a ground plane;
• and
• an electrode substantially coplanar with and capacitively coupled to the ground plane, the electrode and ground plane to form an electric field in response to the input signal;
• and
• controller circuitry electrically coupled to the proximity sensing capacitor, the controller circuitry to detect an object within the electric field based on a change in the output signal;
• and
• an automation apparatus to perform an action in response to the controller circuitry detecting the object within the electric field;
• wherein:
• the output signal has a first frequency associated with the object interacting with the electric field;
• the output signal has a second frequency associated with the object not interacting with the electric field;
• and
• the detection of the object is based on detecting a difference between the first frequency and the second frequency.