Multiple touch plane compatible interface circuit and method

• US 6,765,558 B1
• Filed: 09/29/2000
• Issued: 07/20/2004
• Est. Priority Date: 09/29/2000
• Status: Expired due to Term

• Current Assignee: Rockwell Technologies, LLC
• Original Assignee: Rockwell Automation Technologies Incorporated (Allen-Bradley Co., Inc.)
• Inventors: Dotson, Gary Dan
• Primary Examiner(s): Bella, Matthew C.
• Assistant Examiner(s): NGUYEN, HAU H
• Application Number:
  US09/675,791
• Time in Patent Office: 1,390 Days
• Field of Search: 345/173, 345/174-178, 345/179, 178/19.01, 178/18-1-, 178/87, 340/407.1
• US Class Current: 345/173
• CPC Class Codes: G06F 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact

Abstract

A method of determining a type of touch plane operator input device comprises sensing the impedance across first and second terminals of a touch plane operator input device to distinguish the touch plane operator input device as being one of at least two different types of touch plane operator input devices. A method of processing an input from a touch plane operator input device comprises determining a first location of a first touch on the touch plane operator input device; determining a second location of a second touch on the touch plane operator input device; comparing the first and second locations to obtain an indication of an amount of difference between the first and second locations; and determining whether the indication of the amount of difference exceeds a predetermined amount. These steps are performed by discrete logic circuitry that provides an event notification to a microprocessor when the indication of the amount of difference exceeds the predetermined amount. An interface circuit for a touch plane operator input device comprises a digital signal processor that includes a data processing path along which data from a touch plane operator input device passes while being processed by the digital signal processor. The interface circuit is capable of processing data from first and second different types of touch plane operator input devices. The data path is a common data processing path that is the same for input data for both of the first and second types of touch plane operator input devices.

Claims

1. An interface circuit for a touch plane operator input device, comprising a digital signal processor that includes a data processing path along which input data from a touch plane operator input device passes while being processed by the digital signal processor, wherein the interface circuit is capable of receiving input data in a first signal format from a first type of touch plane operator input device and input data in a second signal format from a second type of touch plane operator input device, the first signal format being different from the second signal format, and the first type of touch plane operator input device being different from the second type of touch plane operator input device, wherein the interface circuit is capable of processing input data from the first and second types of touch plane operator input devices, and wherein the data path is a common data processing path that is the same for input data from the first and second types of touch plane operator input devices, wherein the first type of touch plane operator input device is an 8-wire touch plane operator input device and the second type of touch plane operator input device is one of a 4-wire touch plane operator input device and a 5-wire touch plane operator input device.

2. An interface circuit according to claim 1, wherein the first and second different types of touch plane operator input devices are both analog resistive touch plane operator input devices.

3. An interface circuit according to claim 1, wherein the interface circuit is capable of receiving input data in third and fourth signal formats from third and fourth types of touch plane operator input devices, wherein the third type of touch plane operator input device is a 7-wire touch plane operator input device and the fourth type of touch plane operator input device is the other of the 4-wire touch plane operator input device and the 5-wire touch plane operator input device.

4. An interface circuit according to claim 1, wherein the common data processing path includes an adder circuit that adds successive input data samples to produce a summation of the data samples, and a divider circuit that divides the summation of the input data samples to determine an average data sample location.

5. An interface circuit according to claim 4, wherein the common data processing path includes a comparator circuit that compares successive input data samples to determine a minimum input data sample and a maximum input data sample.

6. An interface circuit according to claim 5, wherein the common data processing path includes a comparator circuit that compares the minimum input data sample with the maximum input data sample range.

7. An interface circuit according to claim 6, wherein the common data processing path includes a comparator circuit that compares the sample range to a predetermined maximum sample range.

8. An interface circuit according to claim 1, wherein the interface circuit further comprises an analog switch matrix, the analog switch matrix having a plurality of analog switches and having a plurality of different configurations defined by on/off states of the plurality of analog switches;

and

wherein, in some of the plurality of different configurations, the interface circuit is capable of processing data from the first type of touch plane operator input device and, in other configurations, the interface circuit is capable of processing information from the second type of touch plane operator input device.

9. The interface circuit of claim 1, wherein the digital signal processor is located on a system-on-chip integrated circuit chip, and wherein the integrated circuit chip also has a microprocessor located thereon.

10. A method of acquiring and evaluating information from a touch plane operator input device comprising:

(a) acquiring a plurality of data samples from the touch plane operator input device;

(b) determining a minimum sample;

(c) determining a maximum sample; and

(d) comparing a difference between the minimum sample and the maximum sample with a predetermined maximum amount;

wherein steps (a)-(d) are performed by discrete logic circuitry that defines a data processing path in an integrated circuit;

wherein the integrated circuit is capable of operation in connection with a plurality of different types of touch plane operator input devices; and

wherein the same data processing path is used for acquiring and evaluating the information from the touch plane operator input device regardless of which type of touch plane operator input device is used.

17. The method of claim 10, further comprising:

(e) comparing a difference between a new average sample and a previous average sample to determine a difference therebetween.

11. An interface circuit comprising:

an analog switch matrix, the analog switch matrix having an input port capable of being coupled to, and receiving input data from, anyone of a plurality of touch plane operator input devices including an 8-wire touch plane operator input device and also another type of touch plane operator input device, the analog switch matrix further having a plurality of analog switches and a plurality of different configurations defined by on/off states of the plurality of analog switches;

an analog-to-digital converter, the analog-to-digital converter being coupled to receive analog input data in a generic format based upon the input data from the analog switch matrix and to produce digital input data based thereon; and

a digital signal processor, the digital signal processor being coupled to receive the digital input data from the analog-to-digital converter, the digital signal processor including a data processing path along which the digital input data passes while being processed by the digital signal processor.

12. An integrated circuit device, the integrated circuit device comprising:

an analog switch matrix, the analog switch matrix having a plurality of analog switches and having a plurality of different configurations defined by on/off states of the plurality of analog switches,

an analog-to-digital converter, the analog-to-digital converter being coupled to receive the input data from the analog switch matrix, and

a digital signal processor coupled to the analog-to-digital converter;

wherein the analog switch matrix is capable of receiving the input data from any one of a plurality of types of touch screens, and

wherein the analog switch matrix provides the input data to the analog-to-digital converter in a generic signal format that remains the same regardless of the type of touch screen providing the input data,

wherein the analog switch matrix has a first output that is connected to an input terminal of the analog-to-digital converter, and a second output that is connected to a first reference terminal of the analog-to-digital converter.

13. The device of claim 12, wherein the first reference terminal is a Ref+ terminal, and wherein the analog switch matrix additionally includes a third output that is connected to a Ref-terminal of the analog-to-digital converter.

14. The device of claim 13, wherein the analog switch matrix includes twenty-seven switches.

15. An integrated circuit device, the integrated circuit device comprising:

an analog switch matrix, the analog switch matrix having a plurality of analog switches and having a plurality of different configurations defined by on/off states of the plurality of analog switches,

an analog-to-digital converter, the analog-to-digital converter being coupled to receive the input data from the analog switch matrix, and

a digital signal processor coupled to the analog-to-digital converter;

wherein the analog switch matrix is capable of receiving the input data from any one of a plurality of types of touch screens, and

wherein the analog switch matrix provides the input data to the analog-to-digital converter in a generic signal format that remains the same regardless of the type of touch screen providing the input data,

wherein the analog switch matrix has eight inputs by which the analog switch matrix is capable of receiving input signals from any of a 4-wire touch screen, a 5-wire touch screen, a 7-wire touch screen and an 8-wire touch screen.

16. An integrated circuit device, the integrated circuit device comprising:

an analog switch matrix, the analog switch matrix having a plurality of analog switches and having a plurality of different configurations defined by on/off states of the plurality of analog switches,

an analog-to-digital converter, the analog-to-digital converter being coupled to receive the input data from the analog switch matrix, and

a digital signal processor coupled to the analog-to-digital converter;

wherein the analog switch matrix is capable of receiving the input data from any one of a plurality of types of touch screens, and

wherein the analog switch matrix provides the input data to the analog-to-digital converter in a generic signal format that remains the same regardless of the type of touch screen providing the input data,

wherein the digital signal processor includes;

an adders circuit that adds successive input data samples to produce a summation of the data samples;

a divider circuit that divides the summation of the input data samples to determine an average data sample location;

a comparator circuit that compares successive input data samples to determine a minimum input data sample and a maximum input data sample; and

a comparator circuit that compares the minimum input data sample with the maximum input data sample to a sample range.

18. An apparatus for receiving and processing touch screen data, the apparatus comprising:

an input port capable of being coupled to, and receiving input signals from, any one of at least three different types of touch screens, wherein each of the received input signals is in a respective signal format corresponding to the type of touch screen from which the input signals were received;

a first circuit capable of converting the input signals into intermediate signals having a generic format regardless of the type of touch screen providing the input signals; and

a second circuit capable of processing the intermediate signals in the generic format, wherein the processing by the second circuit remains the same regardless of the type of touch screen providing the input signals upon which the intermediate signals arc based,

wherein the input port is capable of receiving the input signals from an 8-wire touch screen and also from at least two of a 4-wire touch screen, a 5-wire touch screen and a 7-wire touch screen.

19. An apparatus for receiving and processing touch screen data the apparatus comprising:

an input port capable of being coupled to and receiving input signals from, any one of at least three different types of touch screens, wherein each of the received input signals is in a respective signal format corresponding to the type of touch screen from which the input signal were received;

a first circuit capable of converting the input signals into intermediate signals having a generic format regardless of the type of touch screen providing the input signals; and

a second circuit capable of processing the intermediate signals in the generic format, wherein the processing by the second circuit remains the same regardless of the type of touch screen providing the input signals upon which the intermediate signals are based,

wherein the input port includes at least eight terminals by which an 8-wire touch screen can be coupled to the input port.

20. An apparatus for receiving and processing touch screen data the apparatus comprising:

an input port capable of being coupled to, and receiving input signals from, any one of at least three different types of touch screens wherein each of the received input signals is in a respective signal format corresponding to the type of touch screen from which the input signals were received;

a first circuit capable of converting, the input signals into intermediate signals having a generic format regardless of the type of touch screen providing the input signals; and

a second circuit capable of processing the intermediate signals in the generic format wherein the processing by the second circuit remains the same regardless of the type of touch screen providing the input signals upon which the intermediate signals are based,

wherein the first circuit includes an analog switch matrix that includes more than five switches.

21. The apparatus of claim 20, wherein the first circuit additionally includes an analog-to-digital converter, wherein the analog switch matrix is coupled to at least an input terminal and a reference terminal of an analog-to-digital converter.

22. An apparatus for receiving and processing touch screen data, the apparatus comprising:

an input capable of being coupled to, and receiving input signals from, any one of at least three different types of touch screens, wherein each of the received input signals is in a respective signal format corresponding to the type of touch screen from which the input signals were received;

a first circuit capable of converting the input signals into intermediate signals having a generic format regardless of the type of touch screen providing the input signals; and

a second circuit capable of processing the intermediate signals in the generic format, wherein the processing by the second circuit remains the same regardless of the type of touch screen providing the input signals upon which the intermediate signals are based,

wherein the second circuit includes processing circuitry that performs a plurality of processing operations upon the intermediate signals, wherein the plurality of processing operations includes calculating a range based upon a minimum input value and a maximum input value, and comparing the range with a predetermined maximum deviation value.