Granted Patent B2

US 8,742,901 · App. 13/037,091 · Granted Jun 3, 2014

Abstract

Claims (63)

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; and

generate an event signal; and

a transmitter configured to transmit the event signal.

2. The system of claim 1 , wherein the environmental sensor comprises a passive infrared detector and the environmental condition comprises infrared radiation.

3. The system of claim 1 , wherein the triggering event comprises human movement.

4. The system of claim 1 , wherein the specified sampling rate is between 20 samples per second and 1,000 samples per second.

5. The system of claim 1 , wherein the threshold number of environmental sensor samples comprises between 10 and 300 samples.

6. A method for detecting a change in an environmental condition, comprising:

sampling, at a specified sampling rate, an environmental sensor configured to detect an environmental condition;

storing samples representing the environmental condition in a memory;

generating a wake signal after more than a predetermined number of samples have been stored;

waking a processor from a low-power state when the wake signal is received;

analyzing, using the processor, the environmental sensor samples stored in the memory;

determining that a triggering event has occurred based on the analysis of the environmental sensor samples stored in the memory;

generating an event signal; and

transmitting the event signal.

7. The method of claim 6 , wherein the environmental sensor comprises a passive infrared detector and the environmental condition comprises infrared radiation.

8. The method of claim 6 , wherein the triggering event comprises human movement.

9. The method of claim 6 , wherein the specified sampling rate is between 20 samples per second and 1,000 samples per second.

10. The method of claim 6 , wherein the threshold number of environmental sensor samples comprises between 10 and 300 environmental sensor samples.

11. 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 a plurality of samples generated by the sampling circuitry;

a pre-filter configured to:

perform a simplified analysis of the plurality of samples in the memory;

determine based on the simplified analysis that the plurality of samples indicate a potential change in the environmental condition; and

generate a wake signal based on the plurality of samples indicating the potential change in the environmental condition;

a processor configured to:

receive the wake signal from the pre-filter;

wake from a low-power state based on the wake signal;

analyze the plurality samples in the memory to determine that a triggering event has occurred; and

generate an event signal; and

a transmitter configured to transmit the event signal.

12. The system of claim 11 , wherein the environmental sensor comprises a passive infrared detector and the environmental condition comprises infrared radiation.

13. The system of claim 11 , wherein the triggering event comprises human movement.

14. The system of claim 11 , wherein the specified sampling rate is between 20 samples per second and 1,000 samples per second.

15. The system of claim 11 , wherein the processor is further configured to wake each time a threshold number of environmental sensor samples are stored in the memory.

16. The system of claim 15 , wherein the threshold number of environmental sensor samples comprises between 10 and 300 samples.

17. A method for detecting a change in an environmental condition comprising:

sampling, at a specified sampling rate, an environmental sensor configured to detect an environmental condition;

storing a plurality of samples representing the environmental condition in a memory;

analyzing, using a pre-filter, the plurality of samples in the memory;

determining, using the pre-filter, that the plurality of samples indicate a potential change in the environmental condition;

generating, using the pre-filter, a wake signal based on the plurality of samples indicating the potential change in the environmental condition;

receiving, at a processor, the wake signal from the pre-filter;

waking a processor from a low-power state based on the wake signal;

analyzing the plurality of environmental sensor samples in the memory to determine that a triggering event has occurred;

generating an event signal; and

transmitting the event signal.

18. The method of claim 17 , wherein the environmental sensor comprises a passive infrared detector and the environmental condition comprises infrared radiation.

19. The method of claim 17 , wherein the triggering event comprises human movement.

20. The method of claim 17 , wherein the specified sampling rate is between 20 samples per second and 1,000 samples per second.

21. The method of claim 17 , further comprising:

generating the wake signal each time a threshold number of environmental sensor samples are stored in the memory.

22. The method of claim 21 , wherein the threshold number of environmental sensor samples comprises between 10 and 300 samples.

Assignments (8)