Wireless coordination of audio playback

A non-transitory computer-readable storage medium for use with an electronic device, the computer-readable storage medium storing program instructions that, when executed by the electronic device, coordinates a playback operation by causing the electronic device to perform one or more operations comprising:

• receiving, from one or more antennas in the electronic device, packets associated with a second electronic device, wherein a given packet comprises a transmit time, based on a second clock in the second electronic device, when the second electronic device transmitted the given packet;
• storing receive times when the packets were received, wherein the receive times are based on a clock in the electronic device;
• calculating, based on differences between the transmit times and the receive times, relative drift as a function of time between the clock and the second clock, wherein a given difference is between a given transmit time and a given receive time for a given packet, and wherein the calculation is based on unilateral communication of timing information between the second electronic device and the electronic device;
• adjusting, based on the relative drift, a clock circuit that provides the clock to eliminate the relative drift;
• determining a remaining time offset between the clock and the second clock;
• receiving, from the one or more antennas, information associated with the second electronic device specifying a future time when the electronic device is to perform the playback operation;
• modifying the future time based on the remaining time offset to determine a corrected future time;
• and
• performing the playback operation at the corrected future time, wherein the adjusting the clock and the modifying the future time coordinate the playback operation in a clock domain of the clock to within a predefined value of a clock domain of the second clock.

A method for coordinating a playback operation, comprising:

• by an interface circuit in an electronic device:
• receiving, from one or more antennas in the electronic device, packets associated with a second electronic device, wherein a given packet comprises a transmit time, based on a second clock in the second electronic device, when the second electronic device transmitted the given packet;
• storing receive times when the packets were received, wherein the receive times are based on a clock in the electronic device;
• calculating, based on differences between the transmit times and the receive times, relative drift as a function of time between the clock and the second clock, wherein a given difference is between a given transmit time and a given receive time for a given packet, and wherein the calculation is based on unilateral communication of timing information between the second electronic device and the electronic device;
• adjusting, based on the relative drift, a clock circuit that provides the clock to eliminate the relative drift;
• determining a remaining time offset between the clock and the second clock;
• receiving, from the one or more antennas, information associated with the second electronic device specifying a future time when the electronic device is to perform the playback operation;
• and
• modifying the future time based on the remaining time offset to determine a corrected future time;
• and
• by the electronic device:
• performing the playback operation at the corrected future time, wherein the adjusting the clock and the modifying the future time coordinate the playback operation in a clock domain of the clock to within a predefined value of a clock domain of the second clock.