Multi-sample reading in sleep mode for passive infrared detectors and other analog inputs

摘要

This disclosure provides systems and methods for detecting a change in environmental conditions utilizing sampling circuitry configured to sample an environmental sensor while a processor remains in a low-power state or a sleep state. According to some embodiments, a pre-filter performs a simplified analysis of the sensor samples to determine if the processor should wake and perform additional analysis on stored sensor samples. Specific examples are provided for detecting motion using passive infrared detectors. Accordingly, systems and methods for reducing the power consumption of a motion detection system are provided herein.

主权项

1. A system configured to detect a change in an environmental condition comprising:
an environmental sensor configured to detect an environmental condition; sampling circuitry configured to sample the environmental sensor at a specified sampling rate; a memory configured to store samples generated by the sampling circuitry; a pre-filter configured to generate a wake signal after more than a predetermined number of samples have been stored; a processor configured to:
periodically wake from a low-power state when the wake signal is received;analyze the environmental sensor samples stored in the memory and to determine that a triggering event has occurred; andgenerate an event signal; and a transmitter configured to transmit the event signal.