Self-powered devices and methods

1. A self-powered device configured to selectively communicate with a remote computing device, the self-powered device comprising:

a power circuit electrically coupled to a bus;

a processor electrically coupled to the bus;

a memory electrically coupled to the bus, said memory comprising:

instructions for selecting one of a plurality of modes of operation, wherein the plurality of modes of operation include a first mode of operation in which the self-powered device consumes less than a pre-determined or adaptively-determined amount of power and a second mode of operation in which self-powered device consumes more than the pre-determined or adaptively-determined amount of power;

instructions for conserving power by alternating between the first mode of operation and the second mode of operation, such that the self-powered device is in the second mode of operation during pre-determined or adaptively-determined time intervals, and wherein a duty-cycle of the second mode of operation relative to the first mode of operation is in accordance with a power budget for the self-powered device; and

instructions for communicating with the computing device only during the second mode of operation.

2. The self-powered device of claim 1 , wherein the self-powered device further comprising transmit circuits and receive circuits, wherein the computing device and the self-powered device are time synchronized such that the transmit and receive circuits are powered only during one or more of the time intervals.

3. The self-powered device of claim 2 , wherein the time synchronization is based on a Network Time Protocol.

4. The self-powered device of claim 2 , wherein the time synchronization is based on a periodic beacon signal.

5. The self-powered device of claim 1 , wherein the computing device polls the self-powered device only during one or more of the time intervals.

6. The self-powered device of claim 1 , wherein the self-powered device switches to the second mode of operation prior to one or more of the time intervals, and wherein the self-powered device switches to the first mode of operation after one or more of the time intervals.

7. The self-powered device of claim 1 , wherein the self-powered device further includes instructions for determining a periodicity of the time intervals in accordance with signals provided by the computing device, and wherein the duty-cycle is based on the periodicity.

8. The self-powered device of claim 1 , wherein the self-powered device further includes instructions for combining messages that are to be communicated to reduce communication overhead or reduce energy consumption.

9. The self-powered device of claim 1 , wherein the self-powered device lowers the operating voltage of one or more of its subsystems when in the first mode of operation.

10. The self-powered device of claim 1 , wherein the self-powered device transmits a foreshortened message to the computing device, wherein the message is long enough to maintain the connection with the computing device.

11. The self-powered device of claim 1 , wherein the self-powered device further comprising coordination instructions for assigning communication priorities to the self-powered device and to one or more additional self-powered devices in accordance with power budgets for these devices.

12. The self-powered device of claim 1 , wherein the computing device further includes instructions for providing an acknowledgement message to a sending self-powered device with a higher priority or more quickly than other types of messages.

13. The self-powered device of claim 1 , wherein the power circuit is configured to convert an external energy source into a power signal that powers the self-powered device, where the external energy source is selected from a group consisting of: a thermal energy source, a light energy source, an electromagnetic energy source, a wind energy source, a wave energy source, a kinetic energy source, a magnetic energy source, a chemical energy source, and any combination of the aforementioned sources.

14. The self-powered device of claim 1 , wherein the power circuit includes a component selected from the group consisting of a photovoltaic cell, a wind energy generator, a thermo-electric energy generator, an electromagnetic energy generator, a kinetic energy generator, a piezoelectric device, a magnetic energy generator, and a chemical-to-electricity generator, and any combination of the aforementioned components.

15. The self-powered device of claim 1 , wherein the memory further comprises instructions for being controlled by the computing device.

16. The self-powered device of claim 1 , further comprising one or more sensors.

17. The self-powered device of claim 16 , wherein the one or more sensors measure a characteristic selected from the group consisting of temperature, humidity, pressure, vibration, light, motion, sound, proximity, flow rate, electrical voltage, and electrical current.

18. The self-powered device of claim 1 , wherein the self-powered device provides configuration information to a component in accordance with a measured characteristic, the self-powered device's internal status, any received message, elapsed time, local or remote user interaction, a local automatic process, or a remote automatic process.

19. The self-powered device of claim 18 , wherein the component is selected from the group consisting of a switch, a relay, an electromechanical actuator, a heater, a fan, a speaker, a solenoid, a motor, an electric field generator, a magnetic field generator, and an electro-magnetic field generator.

20. The self-powered device of claim 1 , wherein the self-powered device provides an indication in proportion to output of the circuit powering the self-powered device.

21. The self-powered device of claim 1 , wherein the device provides an indication in proportion to the communication signal between the self-powered device and the computing device or another self-powered device.

22. A networked system, comprising:

a computing device;

a self-powered device configured to selectively communicate with the computing device, the self-powered device comprising:

a power circuit configured to convert an external energy source into a power signal that powers the self-powered device;

a processor electrically coupled to the power circuit;

a memory containing:

instructions for selecting one of a plurality of modes of operation, wherein the plurality of modes of operation include a first mode of operation in which the self-powered device consumes less than a pre-determined or adaptively-determined amount of power and a second mode of operation in which self-powered device consumes more than the pre-determined or adaptively-determined amount of power;

instructions for conserving power by alternating between the first mode of operation and the second mode of operation, such that the self-powered device is in the second mode of operation during pre-determined or adaptively-determined time intervals, and wherein a duty-cycle of the second mode of operation relative to the first mode of operation is in accordance with a power budget for the self-powered device; and

instructions for communicating with the computing device only during the second mode of operation.

23. The system of claim 22 , further comprising one or more additional self-powered devices, wherein each self-powered device has a transceiver to communicate with one or more of the other self-powered devices, wherein only the self-powered device has a transceiver capable of communicating with the computing device, and wherein communication destined for the computing device is relayed through the self-powered device.

24. The system of claim 23 , wherein paths of the communications destined for the computing device are optimized in accordance with the power budgets of all of the self-powered devices.

25. The system of claim 24 , wherein the transceiver duty cycle, transmit power, receive sensitivity, and/or power consumption of the self-powered device is optimized based on the paths of the communications destined for the computing device.

26. A self-powered device configured to selectively communicate with a remote computing device, the self-powered device comprising:

a means for converting an external energy source into a power signal for powering the self-powered device;

a means for processing data;

a means for storing data comprising:

instructions for selecting one of a plurality of modes of operation, wherein the plurality of modes of operation include a first mode of operation in which the self-powered device consumes less than a pre-determined or adaptively-determined amount of power and a second mode of operation in which self-powered device consumes more than the pre-determined or adaptively-determined amount of power;

instructions for conserving power by alternating between the first mode of operation and the second mode of operation, such that the self-powered device is in the second mode of operation during pre-determined or adaptively-determined time intervals, and wherein a duty-cycle of the second mode of operation relative to the first mode of operation is in accordance with a power budget for the self-powered device; and

instructions for communicating with the computing device only during the second mode of operation.