Secondary processor management allowing deep sleep of primary processor

Abstract

The invention is directed to a wireless communication device that includes: a radio unit for performing wireless communications with at least one external device; at least one battery for supplying power to the wireless communication device; and at least one processing unit for controlling the radio unit, wherein the at least one processing unit, includes: host processing unit configured to control execution of one or more active state operations; and a secondary processing unit, coupled to the host processing unit and the radio unit, configured to control execution of one or more low-priority operations while the host processing unit is powered down, wherein the secondary processing unit is further configured to determine if an active-state operation is pending, and if it is determined that an active state operation is pending, to power up the host processing unit to control execution of the active state operation.

What is claimed is: 
     
         1 . A wireless camera system, comprising:
 a plurality of battery-powered, wireless node cameras, each node camera comprising an image sensor for capturing image data, a radio unit for performing wireless communications, at least one processing unit for controlling the image sensor and radio unit, and at least one battery; and   an access point configured to communicate wirelessly with each of the node cameras, and further configured to communicate with a control center that communicatively couples the access point to a computer network,   wherein the at least one processing unit in each node camera, comprises:
 a host processing unit configured to control execution of one or more active state operations; and 
 a secondary processing unit, coupled to the host processing unit and the radio unit, configured to control execution of one or more low-priority operations while the host processing unit is powered down, wherein the secondary processing unit is further configured to determine if an active-state operation is pending, and if it is determined that an active state operation is pending, to power up the host processing unit to control execution of the active state operation, 
   wherein if a low-priority operation is being executed when the active-state operation is determined to be pending, the secondary processor is further configured to suspend the low-priority operation, save information pertaining to a state of the low-priority operation in a memory, and thereafter power up the host processor to control execution of the active-state operation.   
     
     
         2 . The wireless camera system of  claim 1 , wherein the radio comprises a WiFi circuit configured to provide two-way wireless communications in accordance with one or more 802.11 standards. 
     
     
         3 . The wireless camera system of  claim 1 , wherein the secondary processor comprises a microcontroller. 
     
     
         4 . The wireless camera system of  claim 1 , wherein the secondary processor automatically places itself in a sleep mode for a predetermined time if it is determined that there are no pending active-state and low-priority operations. 
     
     
         5 . The wireless camera system of  claim 1 , wherein the secondary processor automatically places itself in a sleep mode for a predetermined time, if there are one or more pending low-priority operations, after completion of the one or more pending low-priority operations.