Method and system for controlling cellular telephone accessory functions

A method for controlling an accessory function by a cellular telephone, comprising:

• generating a message payload by the cellular telephone, the message payload comprising a command to set a selected register on an accessory device to a selected value;
• transmitting the message payload by the cellular telephone to the accessory device;
• storing the selected value in the selected register on the accessory device in response to the message payload;
• periodically reading contents from the selected register by the accessory device;
• and
• controlling the accessory function by the accessory device in response to the contents read from the selected register.

A wireless divice systim comprising:

• an accessory having a processor with an internal memory, the internal memory having a plurality of registers conrtolling respective functions of the accessory;
• and
• a wireless device having a processor operable to generate a message payload, including a command to set a selected register of the accessory processor to a selcted value, and operable to transmit the message payload to the accessory,
• wherein the accesory processor is operable to receive the messeage payload from the wireless device, and operable to store the selected value in the selected register in response to the message payload recived from the wireless device, adn operable to perioically read contents from the selected register and operable to updeat respective functions of the accessory in response to content read from the selected register.