Systems and methods for synchronizing sensor data

• US 8,577,634 B2
• Filed: 12/15/2010
• Issued: 11/05/2013
• Est. Priority Date: 12/15/2010
• Status: Active Grant

• Current Assignee: Allegro Microsystems Incorporated (Sanken Electric Company Limited)
• Original Assignee: Allegro Microsystems Incorporated (Sanken Electric Company Limited)
• Inventors: Donovan, Mark J., Petrie, Craig S., Kozomora, Nevenka, Doogue, Michael C.
• Primary Examiner(s): Raymond, Edward
• Application Number:
  US12/968,353
• Publication Number:
  US 20120158335A1
• Time in Patent Office: 1,056 Days
• Field of Search: 702/79, 702/118, 702182-185
• US Class Current: 702/79
• CPC Class Codes: G01R 25/00 Arrangements for measuring phase angle between a voltage and a current or between voltages or currents
• CPC Class Codes: G05B 19/0423 Input/output
• CPC Class Codes: G05B 2219/25178 Serial communication, data, also repeater
• CPC Class Codes: G05B 2219/25185 Single serial line, virtual second line is earth
• CPC Class Codes: G05B 2219/2637 Vehicle, car, auto, wheelchair

Abstract

A magnetic field sensor including a bidirectional node is configured to perform at least one of generating sensor data, storing sensor data, or communicating sensor data in a serial data signal in response to a trigger signal received at the bidirectional node. An alternative sensor having a node that may or may not be a bidirectional node is configured to reset at least one of a sensor data signal, a clock, a register, or a counter in response to a trigger signal received at the node and is further configured to communicate the sensor data signal in response to the trigger signal.

Claims

1. A sensor comprising a bidirectional node, wherein the sensor is configured to communicate sensor data in a serial data signal having a unidirectional signal format at the bidirectional node in response to a trigger signal received at the bidirectional node.

2. The sensor of claim 1, wherein the sensor is configured to store the sensor data in response to the trigger signal.

3. The sensor of claim 2, wherein the sensor is configured to store the sensor data and to communicate the stored sensor data in the serial data signal in response to detection of a common feature of the trigger signal.

4. The sensor of claim 3, wherein the common feature of the trigger signal is a predetermined edge direction.

5. The sensor of claim 3, wherein the sensor is configured to store the sensor data starting at a first predetermined time after detection of the common feature and to communicate the stored sensor data in the serial data signal starting at a second predetermined time after detection of the common feature.

6. The sensor of claim 2, wherein the sensor is configured to store the sensor data in response to detection of a first feature of the trigger signal and is configured to communicate the stored sensor data in the serial data signal in response to detection of a second feature of the trigger signal.

7. The sensor of claim 6, wherein the first feature of the trigger signal is a first predetermined edge direction and wherein the second feature of the trigger signal is a second, opposite edge direction.

8. The sensor of claim 6, wherein the sensor is configured to communicate the stored sensor data in the serial data signal starting at a predetermined time after detection of the second feature of the trigger signal.

9. The sensor of claim 1, wherein the serial data signal format is selected from Single-Edge Nibble Transmission (SENT), Serial Peripheral Interface 5 (SPI5), or Serial Peripheral Interface (SPI).

10. The sensor of claim 1, wherein the serial data signal comprises an inactive transmission portion and wherein the trigger signal is received during the inactive transmission portion.

11. The sensor of claim 1, wherein the sensor is a magnetic field sensor.

12. The sensor of claim 2, further comprising:

a magnetic field sensing element responsive to a magnetic field associated with an article for providing a magnetic field output signal indicative of the magnetic field;

an interface circuit coupled to receive the magnetic field output signal and configured to generate the sensor data;

a latch coupled to the interface circuit and comprising a latch control node and a digital data output node at which latched digital sensor data is provided in response to detection of the trigger signal at the latch control node;

an encoder coupled to the digital data output node and comprising an encoder control node and a serial data output node; and

a transceiver coupled to the serial data output node and comprising the bidirectional node, wherein the serial data signal is provided at the bidirectional node in response to detection of the trigger signal at the encoder control node.

13. The sensor of claim 12, wherein the magnetic field sensing element comprises a selected one of a Hall effect element or a magnetoresistive element.

14. The sensor of claim 1, wherein the serial data signal comprises one or more of a serial binary signal and a pulse width modulated (PWM) signal.

15. A method for synchronizing sensor output data comprising the steps of:

sensing a characteristic with a sensor and generating sensor data indicative of the characteristic; and

communicating the sensor data in a serial data signal having a unidirectional signal format at a bidirectional node of the sensor in response to a trigger signal received at the bidirectional node.

16. The method of claim 15, further comprising storing the sensor data in response to the trigger signal received at the bidirectional node.

17. The method of claim 16, wherein the storing the sensor data and the communicating the stored sensor data in the serial data signal occur in response to detection of a common feature of the trigger signal.

18. The method of claim 17, further comprising storing the sensor data starting at a first predetermined time after detection of the common feature and communicating the stored sensor data in the serial data signal starting at a second predetermined time after detection of the common feature.

19. The method of claim 16, wherein the storing the sensor data occurs in response to detection of a first feature of the trigger signal and the communicating the stored sensor data in the serial data signal occurs in response to detection of a second feature of the trigger signal.

20. The sensor of claim 19, further comprising communicating the stored sensor data in the serial data signal starting at a predetermined time after detection of the second feature of the trigger signal.

21. The method of claim 15, further comprising receiving the trigger signal from a system controller during an inactive transmission portion of the serial data signal.

22. A sensor comprising a node, wherein the sensor is configured to reset at least one of a sensor data signal, a clock, a register, or a counter in response to a trigger signal received at the node and is further configured to communicate the sensor data signal in response to the trigger signal received at the node.

23. The sensor of claim 22 wherein the node is a bidirectional node and wherein the sensor data signal is provided at the node.

24. The sensor of claim 22 wherein the node is a unidirectional node and wherein the sensor further comprises a second node at which the sensor data signal is provided.

25. The sensor of claim 22 wherein the sensor is configured to reset the at least one of the sensor data signal, the clock, the register, or the counter in response to detection of a first feature of the trigger signal and is configured to communicate the sensor data signal in response to detection of a second feature of the trigger signal.

26. A magnetic field sensor comprising a bidirectional node and configured to perform at least one of (i) generating sensor data, (ii) storing sensor data, (iii) resetting at least one of a sensor data signal, a clock, a register, or a counter, or (iv) communicating sensor data in a serial data signal having a unidirectional signal format in response to a trigger signal received at the bidirectional node.

27. A sensor comprising a bidirectional node, wherein the sensor is configured to communicate sensor data in a serial data signal at the bidirectional node and to store the sensor data in response to a trigger signal received at the bidirectional node.