High Precision Timing for Devices with Sleep Mode in an Electronic Monitoring System

A system for providing a time stamp in an electronic monitoring system, comprising:

• an access point having a first clock circuit;
• and
• at least one monitoring device in communication with the access point, the at least one monitoring device comprising:
• a camera that is configured to obtain images of a monitored area;
• at least one sensor that is operative to generate a trigger signal corresponding to an event detected by the at least one sensor;
• a second clock circuit;
• a first control architecture, wherein the first control architecture is configured to:
• control the camera to obtain the images of the monitored area, and enter an idle state;
• and
• a second control architecture connected to the at least one sensor to receive the trigger signal, wherein the second control architecture is operative to:
• wake the first control architecture from the idle state responsive to receiving the trigger signal, and
• transmit a present time to the first control architecture, wherein the first and second control architectures determine a present time for the first control architecture as a function of a stored time for the first control architecture, a stored time for the second control architecture, and of the present time in the second control architecture.