Interface and communication protocol for a mobile device with a smart battery

• US 20070123304A1
• Filed: 10/13/2006
• Published: 05/31/2007
• Est. Priority Date: 10/14/2005
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Blackberry Limited
• Inventors: Little, Herbert, Pattenden, Christopher, Brubacher, Jonathan, Guthrie, Martin, Book, Christopher
• Granted Patent: US 7,697,957 B2
• Time in Patent Office: Days
• US Class Current: 455/557
• CPC Class Codes: G06F 1/26 Power supply means, e.g. regulation thereof for memories G11C
• CPC Class Codes: H01M 10/4257 Smart batteries, e.g. electronic circuits inside the housing of the cells or batteries
• CPC Class Codes: H02J 7/00036 Charger exchanging data with battery
• CPC Class Codes: H02J 7/00038 using passive battery identification means, e.g. resistors or capacitors identification by mechanical connections H02J7/0045
• CPC Class Codes: H02J 7/00045 Authentication, i.e. circuits for checking compatibility between one component, e.g. a battery or a battery charger, and another component, e.g. a power source
• CPC Class Codes: H02J 7/00047 with provisions for charging different types of batteries
• CPC Class Codes: H04M 1/0262 for a battery compartment
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

Various embodiments are described herein for a mobile communication device that utilizes a smart battery. The mobile device includes a main processor for controlling the operation of the mobile communication device. The smart battery is coupled to the main processor and provides supply power. The smart battery includes a battery processor for controlling the operation of the smart battery and communicating with the main processor, and a battery module having one or more batteries for providing the supply power. A battery interface is provided for coupling between the main processor and the battery processor for providing communication therebetween. The battery interface comprises a data communication line and protection circuitry for protecting the main processor from electrostatic discharge. A communication protocol is also provided for communication between the main processor and the battery processor.

Claims

1. A mobile communication device comprising:

a main processor for controlling the operation of the mobile communication device;

a smart battery coupled to the main processor, the smart battery being adapted to provide supply power to the mobile device, the smart battery comprising a battery processor for controlling the operation of the smart battery and communicating with the main processor; and

a battery module having one or more batteries for providing the supply power; and

a battery interface coupled between the main processor and the battery processor for providing communication therebetween, wherein the battery interface comprises a data communication line and protection circuitry for protecting the main processor from electrostatic discharge.

2. The mobile communication device of claim 1, wherein the protection circuitry comprises an RC network.

3. The mobile communication device of claim 2, wherein the main processor comprises a transmit pin for transmitting data to the smart battery and a receive pin for receiving data from the smart battery, the smart battery comprises an input/output pin, and the protection circuitry comprises a first resistor with a first node coupled to the transmit pin and a second node coupled to the receive pin, a second resistor with a third node coupled to the second node of the first resistor and a fourth node coupled to the input/output pin of the smart battery, and a capacitor coupled between the fourth node of the second resistor and ground, and the data communication line is bi-directional and comprises the first resistor and second resistors.

4. The mobile communication device of claim 3, wherein the main processor is configured as an open drain device and the first resistor is configured as a pull-up resistor.

5. The mobile communication device of claim 2, wherein the RC network is configured to connect the main processor and the battery processor via the data communication line configured as a single half-duplex communication line with a data rate limited to approximately 300 bits per second.

6. The mobile communication device of claim 2, wherein the mobile communication device further comprises a power management module coupled to the smart battery and configured to detect whether the smart battery is coupled to the mobile communication device, and the battery interface comprises first and second tri-state buffers coupled between the RC network and the main processor for preventing data transmission from the main processor to the smart battery when the power management module communicates with the smart battery.

7. The mobile communication device of claim 6, wherein the main processor comprises a transmit pin for transmitting data to the battery processor, a receive pin for receiving data from the battery processor and a transmit enable pin, the smart battery comprises an input/output pin, the first and second tri-state buffers both comprise an input node, an output node and a control node, the input node of the first tri-state buffer is coupled to the transmit pin, the control input of the first tri-state buffer is coupled to the transmit enable pin, the output node of the second tri-state buffer is coupled to the receive pin, the control input of the second tri-state buffer is coupled to ground, and the RC network comprises a first resistor with a first node coupled to the output node of the first tri-state buffer and a second node coupled to the input node of the second tri-state buffer, a second resistor with a third node coupled to the second node of the first resistor and a fourth node coupled to the input/output pin of the smart battery, and a capacitor coupled between the fourth node of the second resistor and ground.

8. The mobile communication device of claim 2, wherein the smart battery further comprises a battery identification resistor coupled to an input/output node of the smart battery for backwards compatibility with mobile communication devices that are not configured to communicate with smart batteries.

9. The mobile communication device of claim 8, wherein the smart battery further comprises a second RC network coupled between the input/output node of the smart battery and an input/output node of the battery processor for electrostatic discharge protection.

10. The mobile communication device of claim 2, wherein the mobile communication device comprises a device memory coupled to the main processor and the smart battery comprises a battery memory, wherein the device memory and the battery memory comprise different portions of security information used for authentication of the smart battery.

11. A method of communicating between a main processor of a mobile communication device and a battery used by the mobile communication device, wherein the method comprises:

providing a communication interface between the main processor and the battery to provide communication therebetween;

sending a protocol version request packet from the main processor to the battery;

initiating authentication of the battery by the main processor if the battery provides a protocol version response packet to the main processor in response to the protocol version request packet; and

reading a battery ID resistor of the battery if the battery does not provide a protocol version response packet to the main processor in response to the protocol version request packet.

12. The method of claim 11, wherein the authentication comprises:

sending a pre-computed battery authentication challenge packet from the main processor to the battery;

generating a battery authentication response at the battery;

sending a battery authentication response packet comprising the battery authentication response from the battery to the main processor; and

comparing the battery authentication response with a pre-computed battery authentication response at the main processor to determine if authentication is successful.

13. The method of claim 12, wherein if authentication is successful, the method further comprises:

sending a battery information request packet from the main processor to the battery;

generating a battery information request packet at the battery comprising battery information on operation of the battery; and

sending the battery information request packet from the battery to the main processor.

14. The method of claim 11, wherein if the battery is a smart battery and a packet with an unknown code is received at the smart battery, the method further comprises sending the protocol version response packet from the smart battery to the main processor.

15. The method of claim 11, wherein the protocol version response packet comprises a protocol version that indicates the version of the battery communication protocol being used.

16. The method of claim 15, wherein the protocol version comprises a minor version number and the method comprises increasing the minor version number for each backwards-compatible change.

17. The method of claim 15, wherein the protocol version comprises a major version number and the method comprises increasing the major version number for each change that is not backwards-compatible.

18. The method of claim 11, wherein the method further comprises providing the communication interface with protection circuitry for protecting the main processor from electrostatic discharge.

19. The method of claim 18, wherein the method further comprises configuring the protection circuitry to limit the data rate of the communication interface to approximately 300 bits per second.

20. A battery for a mobile communication device comprising a main processor for controlling the operation of the mobile communication device;

the battery being able to be coupled to the main processor and being adapted to provide power to the mobile device, the battery comprising;

a battery processor for controlling the operation of the battery and communicating with the main processor;

a battery module having one or more batteries for providing power; and

a battery interface that is able to be coupled between the main processor and the battery processor for providing communication therebetween, wherein the battery interface comprises a data communication line and protection circuitry for protecting the main processor from electrostatic discharge when the battery is coupled to the mobile device.

21. A computer readable medium for communicating between a main processor of a mobile communication device and a battery used by the mobile communication device, the computer readable medium embodying software executable by said main processor for implementing the steps of:

sending a protocol version request packet from the main processor to the battery;

initiating authentication of the battery by the main processor if the battery provides a protocol version response packet to the main processor in response to the protocol version request packet; and

reading a battery ID resistor of the battery if the battery does not provide a protocol version response packet to the main processor in response to the protocol version request packet.