Method and system for controlling cellular telephone accessory functions

• US 6,603,986 B1
• Filed: 01/31/2000
• Issued: 08/05/2003
• Est. Priority Date: 02/01/1999
• Status: Expired due to Term

• Current Assignee: Sony Corporation (Sony Group Corp.), Sony Electronics Inc. (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.), Sony Electronics Inc. (Sony Group Corp.)
• Inventors: Bozoukov, Theodore S.
• Primary Examiner(s): Le, Thanh Cong
• Assistant Examiner(s): TRINH, TAN H
• Application Number:
  US09/494,832
• Time in Patent Office: 1,282 Days
• Field of Search: 455/569, 455/567, 455/571, 455/414, 455/550
• US Class Current: 455/569.2
• CPC Class Codes: H04M 1/6041 Portable telephones adapted for handsfree use
• CPC Class Codes: H04M 1/6075 adapted for handsfree use in a vehicle H04M1/6058 takes precedence; arrangements for holding telephones in a vehicle B60R11/0241
• CPC Class Codes: H04M 1/72409 by interfacing with external accessories hands-free H04M1/60
• CPC Class Codes: H04M 1/724098 Interfacing with an on-board device of a vehicle for hands-free speaking in vehicles H04M1/6075

Abstract

A method and system for controlling an accessory function by a cellular telephone are disclosed. In accordance with the method, the cellular telephone generates a message payload comprising a command to set a selected register on an accessory device to a selected value. The cellular telephone transmits the message payload to the accessory device. The selected value is stored in the selected register on the accessory device in response to the message payload. The accessory device periodically reads the contents of the selected register. The accessory device controls the accessory function in response to the contents read from the selected register. The simple message protocol uses memory and bandwidth resources efficiently, and allows additional accessory functions to be readily controlled without significant modifications to the protocol.

Claims

1. A cellular telephone system comprising

an accessory having a processor with an internal memory, the internal memory having a plurality of registers controlling respective functions of the accessory, and

a cellular telephone having a processor operable to generate a message payload, including a command to set a selected register of the accessory processor to a selected value, and operable to transmit the message payload to the accessory;

wherein the accessory processor is operable to receive the message payload from the cellular telephone, and operable to store the selected value in the selected register in response to the message payload received from the cellular telephone, and operable to periodically read contents from the selected register and operable to update respective functions of the accessory in response to the contents read from the selected register.

2. The cellular telephone system of claim 1, further comprising a communication link operable to carry the commands from the cellular telephone to the accessory.

3. The cellular telephone system of claim 2, wherein the communication link comprises a multi-pin connector.

4. The cellular telephone system of claim 2, wherein the communication link comprises a data in line for carrying data from the accessory to the cellular telephone, a data out line for carrying data from the cellular telephone to the accessory, and a clock line for carrying clock signals between the cellular telephone and the accessory.

5. The cellular telephone system of claim 4, wherein the communication link further comprises an audio in line for carrying audio signals from the accessory to the cellular telephone, and an audio out line for carrying audio signals from the cellular telephone to the accessory.

6. The cellular telephone system of claim 1, wherein the accessory comprises a hands free kit.

7. The cellular telephone system of claim 1, wherein the accessory processor is operable to write data to the registers in response to user input received by the accessory.

8. 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.

9. The method of claim 8, wherein generating the message payload by the cellular telephone comprises:

generating a message type byte identifying the message payload as a command to set a selected register on an accessory device to a selected value;

generating an index byte identifying the selected register; and

generating a data byte identifying the selected value.

10. The method of claim 8, wherein transmitting the message payload by the cellular telephone to the accessory device comprises:

generating a checksum value from the message payload;

generating a message comprising a start flag, the message payload, the checksum value and an end flag; and

transmitting the message from the cellular telephone to the accessory device.

11. The method of claim 10, wherein transmitting the message from the cellular telephone to the accessory device comprises transmitting the message on a data out line simultaneously with a clock signal provided on a clock line.

12. The method of claim 10, wherein generating the message further comprises:

generating a message type byte identifying the message payload as a command to set a selected register on an accessory device to a selected value;

generating an index byte identifying the selected register;

generating a data byte identifying the selected value;

comparing the data byte to a set of one or more reserved values to determine whether the data byte matches one of the set of reserved values;

generating a flag byte in response to a determination that the data byte matches one of the set of reserved values; and

altering the data byte in response to a determination that the data byte matches one of the set of reserved values.

13. The method of claim 12, wherein altering the data byte comprises performing an exclusive-OR operation with the data byte and a selected byte value.

14. The method of claim 12, wherein generating the message further comprises:

comparing the index byte to a set of one or more reserved values to determine whether the index byte matches one of the set of reserved values;

generating a flag byte in response to a determination that the index byte matches one of the set of reserved values; and

altering the index byte in response to a determination that the index byte matches one of the set of reserved values.

15. The method of claim 8, further comprising transmitting an acknowledge message by the accessory device in response to the message payload.

16. The method of claim 15, further comprising:

inspecting the acknowledge message by the cellular telephone to determine whether the message payload was correctly transmitted and acknowledged; and

retransmitting the message payload by the cellular telephone to the accessory device in response to a determination that the was not correctly transmitted or acknowledged.

17. 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.

18. The wireless device system of claim 17, wherein the wireless device is a personal digital assistant (PAD).