Low-power vehicle detection

A parking meter comprising:

• a proximity sensor configured to detect an object in proximity to the parking meter based on a proximity measurement, and configured to produce a trigger signal in response to the detection of the object;
• a directional sensor configured to detect a direction of the object relative to the meter;
• and
• a control module coupled to the magnetometer and the directional sensor and configured to:
• receive the trigger signal from the proximity sensor and, in response to receiving the trigger signal, activate the directional sensor,
• receive sensor data from the directional sensor,
• determine a presence of an object, or lack thereof, in the predetermined direction based on the directional sensor data, and
• upon a positive determination of the presence of the object, store an indication of the presence of the object along with a time of the positive determination.