SYSTEM AND METHOD FOR SENDING MULTIPLE INFRARED (IR) DATA PACKETS USING A SINGLE KEYPRESS

Abstract: An infrared (IR) remote control and method for operating same include assigning and transmitting multiple IR data words for a single remote control keystroke. In accordance with the invention, two IR data words, one corresponding to an analog command and one corresponding to a digital command, are sent by the remote control transmitter. The two data words are sequentially transmitted so that both an analog and a digital settop IR receiver will receive both data words. The analog settop receiver will respond to the analog command and the digital settop receiver will respond to the digital command. In this manner, a single remote control device may be used with both an analog settop receiver and a digital settop receiver.

Description: TITLE OF THE INVENTION SYSTEM AND METHOD FOR SENDING MULTIPLE INFRARED (IR) DATA PACKETS USING A SINGLE KEYPRESS TECHNICAL FIELD The present invention relates generally to the transmission of wireless infrared (IR) signals from a remote control, and, more particularly, to a system and method for sending multiple IR packets using a single remote control keypress. BACKGROUND OF THE INVENTION The use of wireless IR communications has been known for quite some time. A typical application for such IR communications has been, and currently is, for remote control of electronic devices. For example, the remote control that is used with most television sets, video cassette recorders (VCR's), home audio systems, etc., makes use of IR technology to communicate commands from the remote control device to the electronic equipment. Such commands may be used to control whether the device is on or off, to control the volume, to control the channel to which the device is tuned, etc. Typically, the remote control includes circuitry that detects the actuation of one of the control keys, or buttons. Each control key on the remote control has a digital code associated therewith. When a particular key is pressed the logic within the remote control determines the code associated with the pressed key, modulates an IR radio frequency (RF) carrier with that code, and transmits an IR signal containing the code associated with the pressed key to a receiver located at the electronic device. In some applications the IR receiver may be located within the electronic device, and in other applications the IR receiver may reside in a separate control box. For example, the receiver may be located within a settop cable television control box associated with a television set. In the past, settop control boxes were of an analog nature. Many of the commands were common across various brands and types of remote control devices. With the advent of digital devices, such as digital settop control boxes, which also use IR remote control, new commands have been introduced. Some of these new commands perform similar functions to their analog counterparts and some of the new commands are unique to the digital devices. Similarly, some of the analog commands are unused by the digital devices. One of the drawbacks that suppliers of both analog and digital devices have encountered is that a different remote control device is necessary to control both the analog and digital devices. Therefore, there is a need for a single remote control to function with both analog and digital devices. SUMMARY OF THE INVENTION One preferred embodiment of the invention provides an infrared (IR) remote control comprising circuitry configured to assign a plurality of data words to a single keystroke and circuitry configured to transmit the plurality of data words to a receiver. Through this dual transmission technique, one remote control is able to control a plurality of different receivers. One preferred embodiment of the present invention may also be conceptualized as a method for operating an infrared (IR) remote control comprising the following steps: assigning a plurality of data words to a single keystroke and transmitting the plurality of data words to a receiver. BRIEF DESCRIPTION OF THE DRAWINGS The present invention, as defined in the claims, can be better understood with reference to the following drawings. The components within the drawings are not necessarily to scale relative to each other, emphasis instead being placed upon clearly illustrating the principles of the present invention. Fig. 1 is a schematic view illustrating an IR remote control; Fig. 2 is a schematic view illustrating the IR remote control of Fig. 1 communicating with a settop receiver; Fig. 3 is a schematic view illustrating the keypad IR logic of one preferred embodiment of the invention; Fig. 4 is a graphical illustration showing one example dual key transmission of one preferred embodiment of the invention; and Fig. 5 is a flowchart illustrating the operation of one preferred embodiment of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The keypad IR logic of one preferred embodiment of the invention can be implemented in hardware, software, firmware, or a combination thereof. In the preferred embodiment(s), the keypad IR logic is implemented in software or firmware that is stored in a memory and that is executed by a suitable instruction execution system. If implemented in hardware, in an alternative embodiment, the keypad IR logic can be implemented with any or a combination of the following technologies, which are all well known in the art: a discrete logic circuit(s) having logic gates for implementing logic functions upon data signals, an application specific integrated circuit having appropriate logic gates, a programmable gate array(s) (PGA), a fully programmable gate array (FPGA), etc. Turning now to the drawings, Fig. 1 is a schematic view illustrating IR remote control 100, although the buttons shown include only a subset of those that exist on an example remote control, as discussed below. IR remote control 100 includes keypad matrix 123, which includes horizontal lines, an exemplary one of which is indicated by reference numeral 127, and vertical lines, an exemplary one of which is illustrated by reference numeral 128. Typically, buttons on IR remote control 100 are located at the intersection of horizontal lines 128 and vertical lines 127. When actuated, i.e., pressed, the button associated with the intersection of horizontal lines 127 and vertical lines 128 within keypad matrix 123 causes an electrical connection to be made at the intersecting lines. In this manner, when a button is pressed, a circuit is completed at the particular intersection of vertical and horizontal lines corresponding to the pressed button and a signal is sent via communication bus 126 to processor 112. Processor 112 analyzes the received signal and, depending upon which horizontal line and which vertical line are indicated by the button press, determines which function or key has been pressed. IR remote control 100 also includes power source 101, which is typically a replaceable battery, and bypass capacitor 102. Power source 101 and bypass capacitor 102 are grounded at location 104 and communicate via connection 106 with processor 112. Processor 112 is also connected via connection 111 to an indicator light emitting diode (LED) 108. Indicator LED 108 indicates when an IR signal is being transmitted and also functions as a low battery indicator. Processor 112 is also connected via connection 109 to electrically erasable programmable read only memory (EEPROM) 107. EEPROM 107 contains the IR remote control functions in a non-volatile memory arrangement so that when the battery in the remote control is replaced the remote control does not lose its memory. Processor 112 communicates via connection 114 with memory 116. Memory 116 is typically a random access memory (RAM) that contains the keypad IR logic 120 of the invention. As will be described in further detail below, when processor 112 detects a key press from keypad matrix 123, processor 1 12 accesses memory 116 and keypad IR logic 120 to determine which IR code corresponds to the detected key press. Once the processor 112 determines the correct IR code based on the detected key press, the processor 112 communicates with IR transmitter 121 via connection 122 to send an appropriate IR signal containing the appropriate key code to an IR receiver. Fig. 2 is a schematic view illustrating the IR remote control 100 communicating with settop receiver 200. As mentioned above, IR remote control 100 transmits an IR signal, which is received in the settop receiver 200 by IR receiver 201. Although illustrated as being transmitted to a settop receiver 200, the IR signal transmitted by IR remote control 100 can be received by any communication box such as the settop receiver 200, directly by a television (not shown), and by any of a number of new interactive television control boxes. IR receiver 201 demodulates the received IR signal (i.e., removes the modulated carrier), and transfers, via connection 202, the serial data stream to the settop processor 204. Settop processor 204 decodes the serial bit stream data and stores the value in memory 209. After the value has been stored, settop processor 204 generates an interrupt, which informs operating software 211 that an IR event has been received. Operating software 21 1 then retrieves the register value from memory 209 via bus 208 and performs the required action corresponding to the received IR code. In accordance with the invention, there are some instances when it is desirable to transmit multiple function codes using a single key press. An instance in which the ability to transmit multiple function codes per key press can be illustrated by considering the case of both an analog settop receiver box and a digital settop receiver box. Typically, a user will have either an analog model of the settop box or a digital model of the settop box. Presently, according to one example of the invention, there are four functions for each analog and digital settop box that are not used in the other box (although shown in Figs. 1 and 2). For example while an analog settop box includes a "menu" function, a digital settop box includes a "settings" function. Specifically, the analog settop box uses the menu function while the digital settop box does not use that feature. Similarly, the digital settop box uses the settings function while the analog settop box does not. In accordance with one aspect of the invention, one keypress, or keystroke, of IR remote control 100 will transmit both a settings IR word and a menu IR word when a menu/settings button is pressed on a single IR remote control 100. Furthermore, because a current IR protocol sends continuous IR words spaced at 37 milliseconds apart, the settop receiver box determines key press events and key release events from the starting and stopping of these continuous streams of data words. In accordance with one aspect of the invention, a minimal time of 43 milliseconds is inserted between different IR words such that the settop receiver box can determine that new or different key presses are received. IR words not used by a particular settop receiver are ignored. For example, the digital settop receiver ignores the "menu" IR word and responds to the "settings" IR word. The above-mentioned menu/settings keys can be considered dual function keys in that for one press of the menu/settings IR remote control button, two IR coded data words (one corresponding to the menu function (analog) and one corresponding to the settings function (digital) are sent spaced at least 43 milliseconds apart. Shown below in example Table 1 are three additional dual function keys in which one press of an IR remote control button sends two IR codes. Specifically, the "menu/exit key" sends both the menu function, which is detected and responded to by an analog settop box, and the exit function, which is detected and responded to by a digital settop box. Alternatively, the functions of the "menu/exit" key and the "menu/settings" key may be combined into a single button on the remote control. In such an embodiment the remote control determines whether the "settings" or "exit" code should be sent based on which of those codes was most previously sent. Similarly, the "previous day/page-" key sends a previous day function code, which is detected and responded to by an analog box, while also sending a page down function, which is detected and responded to by a digital settop box. Lastly, the "next day/page+" key sends a next day function code, which is detected and responded to by an analog settop box while also sending the page up function, which is detected and responded to by a digital settop box. TABLE 1 Fig. 3 is a schematic view illustrating the keypad IR logic 120 of one preferred embodiment of the invention. Keypad IR logic 120 includes key library 125 in communication via connection 129 with dual key transmission logic 130. Key library 125 stores all of the available key codes. Referring back to Fig. 1. when processor 112 detects a key press from keypad matrix 123, the processor 112 communicates with keypad IR logic 120 to determine whether a single key transmission or whether a dual key transmission is appropriate. Keypad IR logic 120 also includes single key transmission logic 131 in communication with key library 125 via connection 132. If processor 112 detects a key press that requires a single key transmission, then key library 125 communicates the appropriate single word IR code via connection 132 to single key transmission logic 131, which then communicates with processor 112 via connection 114 so that a single key transmission is affected via IR transmitter 121 (Fig. 1). In accordance with the invention, if processor 112 detects a key press event from keypad matrix 123 that requires one of the above-mentioned dual key transmissions, then dual key transmission logic 130 communicates with key library 125 via connection 129 to determine which dual key transmission has been requested. When the dual key transmission logic 130 determines the appropriate dual key transmission, dual key transmission logic 130 communicates via connection 114 to processor 112 so that the appropriate dual key transmission can occur. Fig. 4 is a graphical illustration 300 showing one example of the dual key transmission as described above. Assuming that the menu/settings key has been initially pressed, and after an appropriate waiting period of, for example, greater than 43 milliseconds, 43.2 milliseconds being illustrated with respect to Fig. 4, the settings IR code 301 is transmitted in the form of an IR packet from IR remote control 100 to settop receiver 200. After completion of the transmission of the settings IR code 301 , the dual key transmission logic effects a greater than 43 millisecond delay, in this case 43.2 milliseconds, before transmitting the menu IR code 302. In this manner a single key press (pressing the menu/settings key) on an IR remote control, which can be used with both analog and digital settop boxes, effects the sequential transmission of both the settings IR code 301 and the menu IR code 302. The order of the transmission of the two IR data words is immaterial. Either code word may be sent first. A single key transmission is repeated every 37ms until the key is released. For every dual key transmission both IR packets are transmitted, but not repeated if the key is held down. In neither case is an IR packet truncated. Referring back to Fig. 2, IR receiver 201 demodulates the received IR signal (i.e., removes the modulated carrier), and transfers, via connection 202, the serial data stream to the settop processor 204. Settop processor 204 decodes the serial bit stream data and stores the value in memory 209. After the value has been stored, settop processor 204 generates an interrupt, which informs operating software 211 that an IR event has been received. Operating software 21 1 then retrieves the register value from memory 209 via bus 208 and performs the required action corresponding to the received IR code. If settop receiver 200 is an analog settop receiver than the settop processor will ignore the settings IR code 301 (Fig. 4) and respond to the menu IR code 302 (Fig. 4). If settop receiver 200 is a digital settop receiver, then settop processor 204 will recognize the settings IR code 301 (Fig. 4) and ignore the menu IR code 302 (Fig. 4). In this manner, whether settop receiver 200 is an analog component or a digital component it will receive the appropriate remote control function with a single key press on IR remote control 100. Fig. 5 is a flowchart 400 collectively illustrating the operation of the keypad IR logic 120. The flowchart of Fig. 5 shows the architecture, functionality, and operation of a possible implementation of the keypad IR logic 120 of Figs. 1 and 3. In this regard, each block represents a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that in some alternative implementations, the functions noted in the blocks may occur out of the order noted in Fig. 5. For example, two blocks shown in succession in Fig. 5 may in fact be executed substantially concurrently or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved, as will be further clarified below. Referring now to Fig. 5, shown is a flowchart 400 illustrating the operation of one preferred embodiment of the invention. In block 401 an input (i.e., remote control button press event) is communicated to the IR remote control via a key press. In block 402 it is determined which key was pressed in block 401 and specifically, whether the key requires the transmission of a single IR data word or a dual IR data word. If the selected key type is detected as requiring the transmission of a single IR data word then in block 406 IR remote control 100 will send a single data word. In block 407 it is determined whether the key that effected the transmission of the single data word detected in block 404 has been released. If the key has been released then the system returns to block 401 and awaits additional input. If, in block 407, it is detected that the key has not been released, then in block 408 it is determined whether 37 milliseconds have elapsed. If it is determined in block 408 that 37 milliseconds have not yet elapsed, the system will wait until 37 milliseconds have elapsed. Once 37 milliseconds have elapsed the single data word will be sent again in block 406. In this manner, if a particular key is held down on an IR remote control 100, the system will continue to send that single data word every 37 milliseconds. If in block 402 it is determined that the detected keystroke input requires a dual transmission data word to be sent, then in block 412 the dual data word, as described above with respect to Fig. 4, will be sent. The two data words are separated by an interval of greater than 43 milliseconds. In block 414 it is determined whether or not the dual data word key detected in block 401 has been released. If the dual data word key has not been released then the system will continue to wait until the key is released. If it is determined in block 414 that the dual data word key has been released then the system returns to await further input in block 401. The keypad IR program, which comprises an ordered listing of executable instructions for implementing logical functions, can be embodied in any computer- readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. In the context of this document, a "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The computer readable medium can be. for example but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, device, or propagation medium. More specific examples (a nonexhaustive list) of the computer-readable medium would include the following: an electrical connection (electronic) having one or more wires, a portable computer diskette (magnetic), a random access memory (RAM) (magnetic), a read-only memory (ROM) (magnetic), an erasable programmable read-only memory (EPROM or Flash memory) (magnetic), an optical fiber (optical), and a portable compact disc read- only memory (CDROM) (optical). Note that the computer-readable medium could even be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, via for instance optical scanning of the paper or other medium, then compiled, interpreted or otherwise processed in a suitable manner if necessary, and then stored in a computer memory. It will be apparent to those skilled in the art that many modifications and variations may be made to the preferred embodiments of the present invention, as set forth above, without departing substantially from the principles of the present invention. For example, the present invention can be used in both analog and digital settop box applications. All such modifications and variations are intended to be included herein within the scope of the present invention, as defined in the claims that follow.

Claims: CLAIMS What is claimed is: 1. An infrared (IR) remote control having a communication protocol, said protocol comprising: means for assigning a plurality of data words to a single keystroke; and means for transmitting said plurality of data words. 2. The remote control of claim 1, further comprising means for determining which of said data words to assign to said keystroke. 3. The remote control of claim 1, wherein said plurality of data word assigned to said single keystroke are transmitted at an interval of at least 43 milliseconds (ms). 4. The remote control of claim 1, wherein said keystroke is a key press event. 5. The remote control of claim 1, wherein said plurality of data words are transmitted to an analog settop cable television receiver and a digital settop cable television receiver. 6. The remote control of claim 1, wherein a first portion of said plurality of data words is recognized by an analog settop cable television receiver and a second portion of said plurality of data words is recognized by a digital settop cable television receiver. 7. A method for operating an infrared (IR) remote control, the method comprising the steps of: assigning a plurality of data words to a single keystroke; and transmitting said plurality of data words. 8. The method of claim 7, further comprising the step of determining which of said data words to assign to said keystroke. 9. The method of claim 7, further comprising the step of transmitting said data words assigned to said single keystroke at an interval of at least 43 milliseconds (ms). 10. The method of claim 7, wherein said keystroke is a key press event. 11. The method of claim 7, wherein said plurality of data words are transmitted to an analog settop cable television receiver and a digital settop cable television receiver. 12. The method of claim 7, wherein a first portion of said plurality of data words is recognized by an analog settop cable television receiver and a second portion of said plurality of data words is recognized by a digital settop cable television receiver. 13. An infrared (IR) remote control comprising: circuitry configured to assign a plurality of data words to a single keystroke; and circuitry configured to transmit said plurality of data words. 14. The remote control of claim 13, further comprising circuitry configured to determine which of said data words to assign to said keystroke. 15. The remote control of claim 13, wherein said plurality of data word assigned to said single keystroke are transmitted at an interval of at least 43 milliseconds (ms). 16. The remote control of claim 13, wherein said keystroke is a key press event. 17. The remote control of claim 13, wherein said plurality of data words are transmitted to an analog settop cable television receiver and a digital settop cable television receiver. 18. The remote control of claim 13, wherein a first portion of said plurality of data words is recognized by an analog settop cable television receiver and a second portion of said plurality of data words is recognized by a digital settop cable television receiver. 19. A computer readable medium having a program for operating an infrared (IR) remote control, the program including logic configured to perform the steps of: assigning a plurality of data words to a single keystroke; and transmitting said plurality of data words. 20. The program of claim 19, further comprising logic configured to perform the step of determining which of said data words to assign to said keystroke. 21. The program of claim 19, further comprising logic configured to perform the step of transmitting said data words assigned to said single keystroke at an interval of at least 43 milliseconds (ms). 22. The program of claim 19, wherein said keystroke is a key press event. 23. The program of claim 19, wherein said plurality of data words are transmitted to an analog settop cable television receiver and a digital settop cable television receiver. 24. The program of claim 19, wherein a first portion of said plurality of data words is recognized by an analog settop cable television receiver and a second portion of said plurality of data words is recognized by a digital settop cable television receiver.

Inventors: DRUCKENMILLER STEPHEN, TUCKER JOHN R, DRUCKENMILLER, STEPHEN, TUCKER, JOHN, R.
Applicants: SCIENTIFIC ATLANTA, SCIENTIFIC-ATLANTA, INC.
Application year: 2000
Main classification: G08C23
IPC codes: G08C19, G08C23, H04N5