the following description is provided to enable any person skilled in the art to make and use the invention and sets forth the best modes contemplated by the inventor of carrying out his invention . various modifications , however , will remain readily apparent to those skilled in the art , since the general principles of the present invention have been defined herein specifically to provide an improved rf remote control apparatus for controlling other systems or apparatus . referring now to the drawings and fig1 in particular , a remote control 10 is illustrated . rf signals from the remote control 10 are low power , but adequate to reach an antenna 17 within a spa 16 . the power is preferably low to avoid interference with a neighbor &# 39 ; s radio or television reception . the remote control 10 also receives status signals back from the spa regarding the status of such things as water temperature , and the like as will be explained in greater detail hereafter . the remote control 10 includes a display 11 having icons displayed thereon , which represent various functions to be amplified hereinafter . the remote control 10 also includes a mode button 12 for changing the function of the remote from one mode to another ; and , a switch 13 having a pair of buttons marked +/− (“ on / off ” or “ increase / decrease ”) for use in conjunction with the mode button 12 for changing or setting a function . the remote control 10 is preferably powered by three aaa batters , is preferably waterproof and is preferably capable of floating in water . according to a specific embodiment of the present invention , the remote control 10 operates under the control of a master or main control 15 located within a spa 16 . the main control 15 receives signals from the remote control 10 via an antenna 17 , and transmits information to the remote control by the same antenna 17 . referring now to fig2 , the display 11 of the remote control 10 is shown in greater detail . the display 11 includes numerous icons , which indicate the status of various functions of the spa 16 . a ready light icon 20 will illuminate when the temperature of the water in the spa 16 is within 2 degrees of the selected temperature . a power light icon 21 will illuminate when the spa system is turned on and power is connected . an alpha / numeric display array 22 is disposed for indicating numerous functions selected by the mode switch 12 , or for displaying information received back from the master control 15 . for example , when the temperature mode is selected by pressing the mode button 12 ( fig1 ), a temp light icon 23 illuminates and the temperature of the water 23 a is indicated by the display array 22 . when a temperature set mode is selected by the mode button , a set icon 24 will illuminate . as the +/− switch 13 or buttons 13 are pressed , the temperature is moved up or down as selected and is shown by the display array 22 . as the remote control 10 communicates with the master control 15 , a comm icon 25 will flash , which indicates communication is taking place between the two units . additional functions indicated by the display 11 on the remote control 10 include a water care icon 26 , which when illuminated indicates that the sanitary system of the spa 16 is operating normally or not . a light icon 27 will illuminate when the mode switch 12 selects the spa light function . in the spa light mode , depressing the + button of the switch 13 will turn the spa light 27 on , and depressing the − button of the switch 13 will turn the spa light off . in a similar fashion , when the mode switch 12 has selected the jets mode , a jets icon 28 illuminates and the jets of the spa can be turned on and off using the buttons of switch 13 . a spaudio icon 29 illuminates when the mode switch 12 is stepped to this function . when the + button of the switch 13 is depressed , the spaudio turns on . in a similar manner , when the − button of the switch 13 is depressed , the spaudio turns off . the spaudio feature is explained in greater detail in the u . s . patent application ser . no . 09 / 865 , 127 , entitled spa audio system operable with a remote control , filed may 24 , 2001 , now u . s . pat . no . 6 , 516 , 070 , and assigned to the assignee hereof . a summer timer light icon 30 illuminates when the mode switch 12 is stepped to this function , and when the + of switch 13 is depressed , this function is turned on . in a similar manner , when the − button of this switch 13 is depressed , this function is turned off . the summer timer function is useful in a warm climate . for example , in a place like arizona in the summer time the ambient temperature may be quite high . a feature of the spa 16 is to continuously circulate the water by the heater to maintain a set temperature . in a warm climate , when using the water circulate feature , the water temperature may rise above a desired setting . accordingly , by turning on the summer timer function , the water is not circulated continuously . this helps to maintain the pre - set desired temperature . another function indicated by the display 11 is a lock icon 31 . the lock function can do two things . first , the entire spa system can be locked so that no one can make changes to the settings — unless they have the remote control . secondly , the temperature setting can be locked to a pre - selected setting while the other functions are not locked . referring now to fig3 a through 3e , a variety of displays that may be shown by the display 11 of the remote control 10 are illustrated . fig3 a shows a set temperature display . note that the ready and power icons 20 and 21 , respectively , are illuminated , as well as the set and temp icons , 24 and 23 , respectively ; and , the temperature setting of 103 ° f . is shown . fig3 b shows the display when the remote control 10 is set in the light mode . note that the word light 22 b appears across the display array 22 , while the light icon 27 is illuminated . fig3 c shows the spa 16 is clean when in the water care mode , wherein icon 26 is illuminated and the word clean 22 c appears across the display array 22 . fig3 d shows the display when the status of the spa has a low ph , or high acidity . note that the water care icon 26 is illuminated and the term lo ph 22 d appears across the display array 22 . fig3 e shows the display when the remote is in the jet setting mode . note that the jets icon 28 is lit and the term jets2 22 e appears across the display array 22 . the term jets2 refers to the water - jet pump number 2 . referring now to fig4 , the electronics of the remote control 10 are illustrated . the center of the remote control 10 is a microprocessor unit (“ mpu ”) 35 . the mpu 35 has coupled thereto a ram 36 and a rom 37 , which are conventional peripherals to a microprocessor and will not be described further herein . also , the mpu 35 is powered by a battery 38 , which in a specific embodiment includes three aaa batteries . a battery recharge circuit 39 and a battery monitor 40 are coupled between the battery 38 and the mpu 35 , which are also well known in the art and will not be amplified further herein . a watchdog circuit 41 is also coupled to the mpu 35 to make sure the commands are being executed properly and to reset internal program functions . pushbutton inputs 42 are coupled to input terminals of the mpu 35 to receive signals from the mode button 12 or the +/− selection switch 13 . display driver 43 is coupled to outputs of the mpu 35 in a conventional manner , which in turn drive the display 11 described hereinabove . the display 11 also includes a back light 44 made up of light emitting diodes (“ led ”). an internal monitor 45 is coupled to the mpu for the purpose of determining any mpu non - conforming operation . rf signals are transmitted from the remote control 10 or received from the main control 15 by means of a transceiver 46 and an antenna 47 . the operation of the remote control 10 will be more fully appreciated hereinafter with the description accompanying fig6 a and 6b . at this juncture , reference is made to fig5 a and 5b for a block diagram of the system including the master control 18 which with rf module 60 is the main control 15 . a number of sensing devices are coupled to the master control 18 , such as a temp sensor 50 , which senses the spa water temperature . spa lights 52 are controlled by the master control 15 as are jets 51 and heater 53 . a current sense 54 senses the current in the water heater and jet pumps and provides appropriate inputs indicative thereof to the master control 18 . a water circulating pump 55 and a color wheel 56 are likewise controlled by the master controller 18 . the term color wheel refers to an apparatus for changing the color of the light in the spa , but not necessarily by an actual color wheel . a remote control panel 57 for the spa 16 also provides inputs to the master control 18 . an ozone sensor 58 provides inputs to the master control 15 through an iic ( inter integrated circuit ) bus 59 , which is adapted for the iic protocol . the iic protocol is well known in the art and will not be amplified further herein . referring now to fig5 b , the iic bus 59 is coupled to an rf interface module 60 , which performs an rf to iic slave control . the rf interface module 60 includes a uart ( universal asynchronous receiver / transmitter ), which is an integrated circuit used for serial communications , containing a transmitter ( parallel - to - serial converter ) and a receiver ( serial - to - parallel converter ), each clocked separately . uart &# 39 ; s are well known in the industry and will not be discussed further herein . the remote control 10 , described hereinabove , is adapted to communicate with the master controller 18 by means of the uart . also coupled to the iic bus 59 are such devices as a water treatment 61 and a spaudio 62 , which is disclosed in greater detail in u . s . patent application ser . no . 09 / 865 , 127 , entitled spa audio system operable with a remote control , filed may 24 , 2001 , now u . s . pat . no . 6 , 516 , 070 , and assigned to the assignee hereof . an ir module 63 is also coupled to the iic bus 59 . this module is used for servicing the spa . an infrared (“ ir ”) link couples a remote control 63 . the remote 64 , may , for example , comprise a palmpilot device used by service technicians . palmpilot is a product available from palm , inc . of santa clara , calif . 95052 . a separate control panel 65 for the spa 16 may likewise be coupled to the iic bus 59 . referring now to fig6 a , a flow chart of the operation of the remote control 10 is illustrated . the process begins with an initialization of the mpu 35 ( bubble 100 ) followed by the turning on of the led back - light 44 ( block 101 ). after this , a 15 - second timer is reset ( block 102 ) and a query is made ( block 103 ) for a default lcd from the rf interface module 60 . next , the remote control 10 is placed in normal receive mode ( block 104 ) which is illustrated in fig6 b and amplified hereinafter . after this , an inquiry is made as to whether or not a key was pressed on the remote control 10 ( diamond 105 ). if the answer to this inquiry is yes , then the 15 - second timer is reset ( block 106 ) and this key value is sent to the rf interface module 60 ( block 107 ). next , the lcd from the rf interface module is queried ( block 108 ) and the remote control 10 is again placed in the normal receive mode ( block 104 ). if a key was not pressed , then another inquiry is made as to whether or not the 15 - second timer has expired ( diamond 109 ). if the answer to this inquiry is no , then the remote control is placed in the normal receive mode ( block 104 ). on the other hand , if the answer to this inquiry is yes , then the back - light is turned off ( block 110 ) and the 2 - minute timer is reset ( block 111 ). next , the default lcd from the rf interface module 60 is queried ( block 112 ) and the remote control 10 enters into a sleep mode with a wake up every 18 milliseconds ( block 113 ). after this , an inquiry is made as to whether or not the 2 - minute timer has expired , and if yes it is reset ( connector b returns back to the block 111 ). if the 2 - minute timer has not expired , then yet another inquiry is made as to whether or not the 30 - minute timer has expired ( diamond 115 ). if the answer to this inquiry is no , then still another inquiry is made as to whether or not a key was pressed ( diamond 116 ). if the answer to this inquiry is no , then the remote control enters the sleep mode with a wake up every 18 milliseconds ( block 113 ). on the other hand , if the answer to this inquiry is yes , then a return is made back to the block 102 to reset the 15 - second timer ( via the connector a ). if the 30 - minute timer has expired ( diamond 115 ) then the remote control goes off line ( bubble 117 ). referring now to fig6 b , a flow chart of the nrm process ( normal receive mode ) is shown . the process begins with a start bubble 120 followed by an inquiry as to whether or not data was received ( diamond 121 ). if the answer to this inquiry is yes , then entry is set equal to zero ( entry = 0 , bubble 122 ). entry counts the number of communication attempts between the remote and the rf module . next , the request is sent to the rf interface module 60 ( block 123 ) and the 100 millisecond timer is started ( block 124 ). after this , the rf remote listens to the rf interface module 60 ( fig5 b ) ( block 125 ) for data to determine what should be displayed . an inquiry is then made as to whether or not valid data was received ( diamond 126 ). if the answer to this inquiry is yes , then the data is displayed ( block 127 ) and the process ends ( bubble 128 ). note that if no data was requested ( diamond 121 ), then the nrm process ends . if the data received was not valid , then another inquiry is made as to whether or not the 100 millisecond timer has expired ( diamond 129 ). if the answer to this inquiry is no , then a return is made back to the block 125 . on the other hand , if the 100 millisecond timer has expired then yet another inquiry is made as to whether or not entry is greater than 2 ( diamond 130 ). this is done for the purpose of making sure that the remote and the rf interface module 60 have communicated correctly . if entry is not greater than 2 , then entry is incremented and a return is made back to the block 123 for sending the request back to the rf interface module 60 . on the other hand , if entry is greater than 2 , then the display is cleared ( block 132 ) and the nrm process ends ( bubble 128 ). the methods and apparatus of the present invention , or certain aspects or portions thereof , may take the form of program code ( i . e ., instructions ) embodied in tangible media , such as floppy diskettes , cd - roms , hard drives , or any other machine - readable storage medium , wherein , when the program code is loaded into and executed by a machine , such as a computer , the machine becomes an apparatus for practicing the invention . the methods and apparatus of the present invention may also be embodied in the form of program code that is transmitted over some transmission medium , such as over electrical wiring or cabling , through fiber optics , or via any other form of transmission , wherein , when the program code is received and loaded into and executed by a machine , such as a computer , the machine becomes an apparatus for practicing the invention . when implemented on a general - purpose processor , the program code combines with the processor to provide a unique apparatus that operates analogously to specific logic circuits . while the invention has been particularly shown and described with reference to a preferred embodiment , it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention . those skilled in the art will appreciate that various adaptations and modifications of the just - described preferred embodiments can be configured without departing from the scope and spirit of the invention . therefore , it is to be understood that within the scope of the appended claims , the invention may be practiced other than as specifically described herein .
a spa system including a remote control for controlling operation thereof . the system includes a remote control module having a microprocessor and memory therefor , which is receptive to push - button inputs . the remote control has a display and an antenna for transmitting signals to the spa and for receiving signals back from the spa . a master control module resides within the spa for controlling and sensing a multiplicity of functions of the spa . a slave control module is coupled to the master control module and also has an antenna responsive to command signals received from the remote control , and for transmitting status signals back to the remote control . the slave control module is used for converting the command signals received from the remote control for the master control , and for converting status signals received from the master control for transmission back to the remote control .