Self-powered devices and methods

1. A device, the device comprising:

a processor; and

a memory comprising:

instructions for selecting one of a plurality of modes of operation, wherein the plurality of modes of operation include: (i) a low-power mode of operation in which the device consumes less than a pre-determined or adaptively-determined amount of power and the device has less than full functionality, and (ii) and a high-power mode of operation in which the device consumes more than the pre-determined or adaptively-determined amount of power and the device has more functionality than in the low-power mode wherein the instructions for selecting one of a plurality of modes of operation include instructions for conserving power by transitioning from the high-power mode of operation to the low-power mode of operation.

2. The device of claim 1 , wherein the device is self-powered.

3. The device of claim 1 , further comprising instructions for communicating, at pre-determined or adaptively-determined periodic intervals, with a remote computing device, by periodically enabling a transceiver at the device during the high-power mode of operation.

4. The device of claim 3 , wherein the periodic enabling of the transceiver is performed in accordance with a synchronization of the device with one or more devices on a network.

5. The device of claim 3 , wherein a duty-cycle of the device is aligned with a duty-cycle of the remote computing device such that the transceiver of the device is enabled at the same time as a transceiver of the remote computing device.

6. The device of claim 1 , further comprising instructions for communicating with a central device on a network only during a time-slot, allocated for the device, occurring at a pre-assigned phase within a periodic interval, to avoid contention with other communicating devices on the network.

7. The device of claim 6 , wherein the allocated time-slot is assigned to the device from a plurality of time-slots in accordance with a procedure selected from the group consisting of: a pseudo-random procedure, a round-robin procedure, a fairness procedure, a procedure assigning highest priority to a most energy-poor device, and any combination of the aforementioned procedures.

8. The device of claim 3 , further comprising instructions for a built-in latency to await, at the device, an acknowledgement message from the remote computing device in response to a message transmitted by the device.

9. The device of claim 8 , further comprising instructions to minimize the built-in latency for awaiting the acknowledgement message by a procedure selected from the group consisting of: enforcing immediate acknowledgment of the transmitted message by the remote computing device, enforcing acknowledgment of the transmitted message as a high-priority task by the remote computing device, decoalescing a combined acknowledgement message obtained from a plurality of acknowledgement messages coalesced by the remote computing device, preferentially processing messages where a sender is awaiting a response, and any combination of the aforementioned procedures.

10. The device of claim 1 , further comprising instructions for communicating with one or more remote devices, using a protocol selected from the group consisting of: radio-based protocols, light-based protocols, magnetic-induction-based protocols, and any combination of the aforementioned protocols.

11. The device of claim 1 , further comprising:

a plurality of sub-systems;

an energy collector configured to collect energy to power the device from an environment surrounding the device;

a voltage converter to generate a plurality of output voltages in accordance with voltage requirements of each of the plurality of sub-systems; and

a storage device to store energy.

12. The device of claim 11 , wherein the energy collector is configured to operate at a pre-determined or adaptively-determined optimal operating point, such that an output voltage at a desired output current is designed to yield maximum power from the available input energy collected by the collector from the environment.

13. The device of claim 12 , further comprising instructions for determining the optimal operating point of the energy collector in accordance with one or more of: a variation in an incident light intensity, a variation in an operating temperature, processing conditions of the device, and manufacturing conditions of the device.

14. The device of claim 12 , further comprising instructions for adaptively determining the optimal operating point of the energy collector by iteratively varying current operating points in a direction that results in an increase in a measured power level obtained from the energy collector.

15. The device of claim 14 , further comprising instructions for adaptively determining the optimal operating point under extreme ambient conditions by constraining a number of consecutive iterative steps in a specified direction.

16. The device of claim 1 , further comprising a controller configured to conserve power by operating at a voltage level adapted in accordance with a frequency of operation of the controller and a set of functions to be performed by the controller.

17. The device of claim 16 , wherein the controller comprises non-volatile memory circuits; and the controller is further configured to conserve power by combining a plurality of update operations to the non-volatile memory circuits so as to share among the plurality of update operations, overhead time required for each update operation.

18. The device of claim 1 , further including a single-indicator display configured for conserving energy by use of intermittent power at a frequency above a first predefined threshold such that the single-indicator display appears, to a human eye, to be powered on continuously.

19. The device of claim 18 , wherein the single-indicator display is further configured for conserving energy by use of intermittent power at a duty-cycle below a second predefined threshold such that the single-indicator appears, to the human eye, to be brighter than a desired brightness level.

20. The device of claim 1 , further comprising instructions to automatically initiate communication with an external device, when the device is configured as one or more of: a security sensor to detect a plurality of environmental states, a self-health indicator to communicate a plurality of operating conditions of the device, a heating-ventilation-air-conditioning sensor, and an intercom to process and transmit voice signals.