Patent Publication Number: US-2023139601-A1

Title: System for power consumption balancing in wireless earbuds

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims benefit under 35 U.S.C. § 119(a) to Chinese Application Serial Number 202111282991.3 filed on Nov. 1, 2021, which is incorporated by reference herein in its entirety. 
     BACKGROUND 
     Wireless earbuds are in common use with mobile phones and other communication devices. The small form factor and lack of entangling wires make the wireless earbuds widely popular. But wireless earbuds do have drawbacks. The small size of an earbud means that battery size is limited, so earbuds can run out of power relatively quickly. A challenge exists in managing the battery power of the earbud. 
     SUMMARY 
     In general, In one aspect, one or more embodiments relate to a first earbud configured to communicate with a user media device and a second earbud. The first earbud includes a battery, a battery monitor configured to determine a power level of the battery, a mode controller. The mode controller is configured to receive a first power level value from the battery monitor and a second power level value from the second earbud and make a determination that the first earbud is operating in a primary mode in which the first earbud receives audio data from the user media device and transmits the received audio data to the second earbud. The mode controller is further configured, in response to the determination that the first earbud is operating in the primary mode, switch the first earbud from the primary mode to a secondary mode based on at least one of the first power level and the second power level. 
     In general, in one aspect, one or more embodiments relate to a method including obtaining a first power level value of a battery of a first earbud and a second power level value from a second earbud and making a determination that the first earbud is operating in a primary mode in which the first earbud receives audio data from a user media device and transmits the received audio data to the second earbud. The method further includes, in response to the determination that the first earbud is operating in the primary mode, switching the first earbud from the primary mode to a secondary mode based on at least one of the first power level and the second power level. 
     In general, in one aspect, one or more embodiments relate to a system including a first earbud comprising a first battery and a second earbud comprising a second battery. The first earbud is configured to obtain a first power level value of the first battery, receive, from the second earbud, a second power level value of the second battery, and make a determination that the first earbud is operating in a primary mode in which the first earbud receives audio data from a user media device and transmits the received audio data to the second earbud. In response to the determination that the first earbud is operating in the primary mode, switching the first earbud from the primary mode to a secondary mode based on at least one of the first power level and the second power level. 
     Other aspects of the disclosure will be apparent from the following description and the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    shows a communications topology between paired earbuds and a user media device, in accordance with one or more embodiments of the disclosure. 
         FIG.  2    shows an earbud in accordance with one or more embodiments of the disclosure. 
         FIG.  3    shows a flow diagram, in accordance with one or more embodiments of the disclosure. 
         FIG.  4    shows a flow diagram, in accordance with one or more embodiments of the disclosure. 
         FIG.  5    shows a flow diagram, in accordance with one or more embodiments of the disclosure. 
     
    
    
     Like elements in the various figures are denoted by like reference numerals for consistency. 
     DETAILED DESCRIPTION 
     In general, embodiments of the disclosure provide paired earbuds that switch between primary and secondary modes in order to balance power consumption between the batteries in the two earbuds. In primary mode, an earbud receives audio data from a user media device and transmits the received audio data to the second earbud. In secondary mode, the earbud receives the audio data from another earbud. Each earbud monitors the battery level in each earbud and switches roles between primary mode and secondary mode based on the relative battery levels of both batteries. 
       FIG.  1    shows a communications topology between paired earbuds  150 L and  150 R and user media device  110 , in accordance with one or more embodiments of the disclosure. In  FIG.  1   , earbud  150 L is the left earbud and earbud  150 R is the right earbud. An earbud is a small earphone worn at least partially inside the ear. Also, user media device  110  is represented in  FIG.  1    by a smartphone. However, the showing of a smart phone is by way of example only and should not be construed to limit the scope of the disclosure or the claims herein. In general, user media device  110  may be any device capable of communicating with the earbuds  150 , including, for example, an audio player, a stereo system, a vehicle infotainment system, a wearable device, a laptop computer, a notepad computer, a neckband device worn by a user, and other types of computing devices. 
     Communication links  120 ,  130  and  140  represent several possible two-way wireless communication links between user media device  110  and earbuds  150 R and  150 L and between earbud  150 R and earbud  150 L. Communication links  120 ,  130  and  140  may be any type of wireless communication link, including near field magnetic induction (NFMI), Bluetooth (BT), Bluetooth Low Energy (BLE), or another type of wireless protocol. Thus, communication link  120  between earbuds  150 R and  150 L may be NFMI, BT, BLE or another protocol. Similarly, communication link  130  between earbud  150 L and user media device  110  may be NFMI, BT, BLE or another protocol, and communication link  140  between earbud  150 R and user media device  110  may be NFMI, BT, BLE or another protocol 
     Communication link  130  transmits and receives audio data between user media device  110  and earbud  150 L and also transmits and receives commands and status data between user media device  110  and earbud  150 L. For example, user media device  110  may transmit streaming audio data to earbud  150 L over communication link  130  when the user is listening to music. During a phone call between the user and a remote party, user media device  110  may receive voice audio data of the user from earbud  150 L and transmit voice audio data of the remote party to earbud  150 L over communication link  130 . User media device  110  may also receive on communication link  130  user input commands from earbud  150 L, such as a Mute command, a Volume Up/Down command, a Call End command, and the like. Similarly, user media device  110  may also transmit user input commands to earbud  150 L, such as a Mute command, a Volume Up/Down command, a Call End command, and the like. 
     Communication link  140  transmits and receives audio data between user media device  110  and earbud  150 R and also transmits and receives commands and status data between user media device  110  and earbud  150 R. For example, user media device  110  may transmit streaming audio data to earbud  150 R over communication link  140  when the user is listening to music. During a phone call between the user and a remote party, user media device  110  may receive voice audio data of the user from earbud  150 R and transmit voice audio data of the remote party to earbud  150 R over communication link  140 . User media device  110  may also receive on communication link  140  user input commands from earbud  150 R, such as a Mute command, a Volume Up/Down command, a Call End command, and the like. Similarly, user media device  110  may also transmit user input commands to earbud  150 R, such as a Mute command, a Volume Up/Down command, a Call End command, and the like. 
     Communication link  120  transmits and receives audio data between earbud  150 R and earbud  150 L and also transmits and receives commands and status data between earbud  150 R and earbud  150 L. As will be explained below in greater detail, earbuds  150 R and  150 L are functionally identical and are each capable of operating in either primary mode or secondary mode. 
     In one example of primary mode operation, the primary earbud ( 150 L or  150 R) conducts most of the communications with user media device  110  and performs other functions, such as digital signal processing (DSP) of the audio streams and active noise cancellation (ANC). By way of example, the primary earbud may perform  4 -microphone beam-forming digital signal processing in a situation where each earbud includes two microphones during telephony mode. The DSP in the primary earbud may receive a 2-microphone signal from the secondary earbud over communication link  120  and then perform the 4-microphone beam-forming in the primary earbud. 
     In an example of secondary mode operation, the secondary earbud  150  communicates mostly with the primary earbud  150  and has very limited communication, if any, with the user media device  110 . The secondary earbud  150  does not perform active noise cancellation or most other DSP functions, but instead limits operations mostly to receiving and playing the audio stream received from the primary earbud and providing audio signal received at microphones on the secondary earbud to the primary earbud. 
     The disparity in the functions performed by the primary earbud  150  and the secondary earbud  150  creates a significant difference in power consumption between the two earbuds  150  during normal operation. As a result, one earbud may become drained and require recharging while the other earbud can still work for some time. 
     To address this battery drainage disparity, the earbuds  150 R and  150 L described in this disclosure are capable of switching between primary and secondary modes in a coordinated manner, thereby balancing power consumption between the batteries in the earbuds  150 R and  150 L. To balance the power consumption, each one of earbuds  150 R and  150 L implements a dedicated firmware design that monitors battery life in each earbud  150  and switches roles between primary mode and secondary mode based on the battery life statuses of both batteries. 
       FIG.  2    shows earbud  150  in accordance with one or more embodiments of the disclosure. Because earbuds  150 R and  150 L are functionally identical, the descriptions of earbud  150  in  FIG.  2    applies to both earbud  150 R and earbud  150 L. Earbud  150  includes memory  205 , signal processor  210 , inter-earbud transceiver (X-CVR)  215 , speaker  220 , battery monitor  225 , battery  230 , user transceiver (X-CVR)  235 , one or more microphone(s)  240 , and system bus  250 . In an exemplary embodiment, system bus  250  enables the other components of earbud  150  to communicate with each other. 
     Inter-earbud transceiver  215  transmits and receives audio data, commands, and status information between earbud  150  and the other earbud  150  over communication link  120 . User device transceiver  235  transmits and receives audio data, commands, and status information between earbud  150  and user media device  110  over communication link  130  or  140 . Microphones  240  pick up the voice of the user during telephony mode. Speaker  220  outputs the audio signal during music mode and voice audio during telephony mode. Battery  230  is a rechargeable battery that provides power to all of the components of earbud  150  via a DC power bus (not shown) and a ground bus (not shown). Battery monitor  225  monitors the remaining power (e.g., voltage) on battery  230  and reports the remaining power to the signal processor  210 . 
     Signal processor  210  controls the overall operation of earbud  150  by executing the code of an operating system program (not shown) in memory  205 . The operating system program includes mode controller firmware  201 , which is a battery power balancing program that enables earbud  150  to operate in primary mode and secondary mode and to switch between modes based on battery status. According to the principles of the present disclosure, signal processor  210  operates as a mode controller by executing the mode controller firmware  201  in order to balance the remaining power levels between the batteries in earbuds  150 R and  150 L by determining battery levels in both earbuds and switching modes when predetermined threshold values are satisfied. Signal processor  210  may hereafter be referred to as a “mode controller  210 ” or as simply a “mode controller” in the claims below. Threshold values may be defined in absolute or relative terms. Absolute terms are values that are determinable without additional data (e.g., as a percentage of battery capacity or a predefined battery level). Relative terms are values that are defined relative to a fluctuating value. For example, relative terms may be defined relative to a current battery level (e.g., a percentage of the current battery level of the other earbud). Subsequent thresholds may be less than previous thresholds. In other embodiments, a separate processor (not shown) may operate as a dedicated mode controller that accesses and executes the mode controller firmware  201  in memory  205 . In such a case, the separate processor may generate control messages to interrupt signal processor  210  and to initiate mode switching as described herein. 
     Initially, the user starts using user media device  110 , which syncs with earbud  150 R and earbud  150 L. Either earbud  150  may operate initially as the primary earbud  150 . For the following example, earbud  150 R initiates as the primary and earbud  150 L initiates as secondary. During usage, the battery power level drops in both earbud  150 R and earbud  150 L and the battery power unbalance gap increases due to the heavier processing load of primary earbud  150 R. The gap increase may depend on which functions the user spends more time. Telephony functions consume more power than music streaming, so the power level gap increases more rapidly. The battery power balancing program determines both earbuds battery life and triggers a mode switch if the battery level gap is bigger than a threshold value. The battery power balancing program continues to detect battery life of both earbuds  150 R and  150 L and repeatedly switches modes of each earbud  150 R and  150 L to keep the right and left earbuds battery life gap within subsequent threshold values, so that both batteries  230  drains synchronously. 
       FIG.  3    shows a flow diagram illustrating a method in accordance with one or more embodiments of the disclosure. It is assumed that the method is performed in earbud  150 R by signal processor  210 , which executes the mode controller firmware  201 . It is also assumed in  FIG.  3    that the batteries  230  in earbud  150 R and in earbud  150 L are both initially full charged (i.e., 100% level). 
     Initially, earbud  150 R determines in block  305  whether earbud  150 R is in 
     Primary Mode. Earbud  150 R may start up in Primary Mode by default or if it initially has a higher battery level than earbud  150 L. If Yes in block  305 , earbud  150 R transfers control to  FIG.  4    and begins to operate in Primary Mode. Returning to  FIG.  3   , if No in block  305 , then in block  310  earbud  150 R (in Secondary Mode) receives audio data from earbud  150 L (in Primary Mode) and sends audio data to earbud  150 L. During normal secondary operation, earbud  150 R periodically determines in block  315  if a Switch Mode command has been received from earbud  150 L (in Primary Mode). If No in block  315 , the earbud  150 R continues in block  310  to receive audio date from earbud  150 L. If Yes in block  315 , then earbud  150 R switches to Primary Mode in block  320  and earbud  150 L switches to Secondary Mode. Earbud  150 R then transfers control to  FIG.  5    and begins to operate in Primary Mode. 
     Turning to  FIG.  4   ,  FIG.  4    shows a flow diagram illustrating a method executed by a primary mode earbud, in accordance with one or more embodiments of the disclosure. It is assumed that the flow diagram in  FIG.  4    is performed in earbud  150 R by signal processor  210 , which executes the mode controller firmware  201 . In block  410 , earbud  150 R has initiated operating in Primary Mode after exiting block  305  in  FIG.  3   . Returning to  FIG.  4   , during routine Primary Mode operation, earbud  150 R in block  415  receives and plays audio data from user media device  110 . In block  420 , earbud  150 R also transmits audio data to earbud  150 L (in Secondary Mode), receives audio data from earbud  150 L, and exchanges battery level status data with earbud  150 L. In this manner, each earbud  150 R and  150 L is aware of the battery power level of the other earbud  150 . 
     Earbud  150 R in block  425  periodically (or aperiodically) monitors the power level of battery  230  to determine if the battery power level is below a first threshold value. In one embodiment, the first threshold value may be an absolute value. For example, the first threshold value may be, for example, 50% of full battery power level and represents the first battery power level that triggers a mode switching operation after earbud  150 R initiates operations in Primary Mode. In alternate embodiments, the first threshold value may be a relative value compared to the battery level in the earbud  150 L. For example, the first threshold value may be when the primary battery level is 50% of the secondary battery level. If No in block  425 , earbud  150 R continues to perform block  415  and block  420  until the battery level falls below the first threshold value. If Yes in block  425 , then earbud  150 R in block  430  sends a Switch Mode command to earbud  150 L. 
     In block  435 , earbud  150 R begins to operate in Secondary Mode and transfers control to block  310  in  FIG.  3   . Thereafter, earbud  150 R operates in Secondary Mode by performing blocks  310  and  315  iteratively until a Switch Mode command is received in block  315 . In response to the Switch Mode command, earbud  150 R switches to Primary Mode in block  320  and earbud  150 L switches to Secondary Mode. Earbud  150 R then transfers control to  FIG.  5    and begins to operate in Primary Mode. 
     Turning to  FIG.  5   ,  FIG.  5    shows a flow diagram, in accordance with one or more embodiments of the disclosure. It is assumed that the flow diagram in  FIG.  4    is performed in earbud  150 R by signal processor  210 , which executes the mode controller firmware  201 . 
     In block  510 , earbud  150 R has initiated operating in Primary Mode after switching from Secondary Mode and exiting block  320  in  FIG.  3   . Returning to  FIG.  5   , during routine Primary Mode operation, earbud  150 R in block  515  receives and plays audio data from user media device  110 . In block  520 , earbud  150 R also transmits audio data to earbud  150 L (in Secondary Mode), receives audio from earbud  150 L, and exchanges battery level status data with earbud  150 L. In this manner, each earbud  150 R and  150 L is aware of the battery power level of the other earbud  150 . 
     Earbud  150 R in block  525  periodically or (aperiodically) monitors the power level of battery  230  to determine if the battery power level is below a subsequent threshold value. Since earbud  150 R (in Primary Mode) has already been in Secondary Mode, the first threshold level in  FIG.  4    has already been reached by earbud  150 . The subsequent threshold value is a smaller threshold value than the first threshold level. For example, the subsequent threshold level may be defined in absolute terms (e.g., 30% battery power) or may be a relative value (e.g., 10% below the battery level of the secondary earbud). If No in block  525 , earbud  150 R continues to perform block  515  and block  520  until the battery level falls below the subsequent threshold value. If Yes in block  525 , then earbud  150 R in block  530  sends a Switch Mode command to earbud  150 L. 
     In block  535 , earbud  150 R begins to operate in Secondary Mode and transfers control to block  310  in  FIG.  3   . Turning to  FIG.  3   , earbud  150 R operates in Secondary Mode by performing blocks  310  and  315  iteratively until a Switch Mode command is received in block  315 . In response to the Switch Mode command, earbud  150 R switches to Primary Mode in block  320  and earbud  150 L switches to Secondary Mode. Earbud  150 R then transfers control to  FIG.  5    and begins to operate in Primary Mode. 
     In the detailed description of embodiments of the disclosure, numerous specific details are set forth in order to provide a more thorough understanding of the disclosure. However, it will be apparent to one of ordinary skill in the art that the disclosure may be practiced without these specific details. In other instances, well-known features have not been described in detail to avoid unnecessarily complicating the description. 
     Throughout the application, ordinal numbers (e.g., first, second, third, etc.) 
     may be used as an adjective for an element (i.e., any noun in the application). The use of ordinal numbers is not to imply or create any particular ordering of the elements nor to limit any element to being only a single element unless expressly disclosed, such as by the use of the terms “before”, “after”, “single”, and other such terminology. Rather, the use of ordinal numbers is to distinguish between the elements. By way of an example, a first element is distinct from a second element, and the first element may encompass more than one element and succeed (or precede) the second element in an ordering of elements. 
     Further, although the description includes a discussion of various embodiments of the disclosure, the various disclosed embodiments may be combined in virtually any manner. All combinations are contemplated herein. 
     While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.