The disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all rights in the copyrighted material.
A computer program listing appendix is included as part of this disclosure. The program listing consists of a Chime Code Module 1, and a Chime Code Module 2, attached hereto and incorporated herein.
This application relates generally to an audio tone generating device.
More specifically, this application relates to a flexible audio tone generating device for use in a consumer appliance, the device capable of playing a melody having a pleasing, adjustable tone.
A typical beeper circuit used in an appliance is shown in
Furthermore, voltage controlled amplifier circuits are also in use to generate audio tones. However, such circuits are relatively expensive. An alternative that utilizes existing appliance components and/or generates a pleasing audio tone at a lower cost would be beneficial.
Provided is a circuit for producing a pleasing audio signal, the circuit including a ramp and decay circuit that results in a graduated tone signal that is pleasing to hear.
Also provided is the above device capable of operating at multiple frequencies to provide additional distinct tones.
Further provided is a notification device for an appliance comprising: a microprocessor for executing a computer program for generating a first output signal and a second output signal; an electronic circuit for inputting the first output signal and for inputting the second output signal; and an output transducer connected to the electronic circuit for producing a musical notification sound for notifying a user of an appliance status.
The first output signal provides an oscillating signal to drive the electronic circuit to produce a musical note of the musical notification sound; and the second output signal provides a trigger signal to trigger and hold the musical note.
Also provided is an appliance utilizing the above described device.
Still further provided is a method for notifying a user of a status of an appliance comprising the steps of:
The invention is a flexible, adjustable circuit for generating an audio signal for providing an indication to a user, such as might be utilized by a consumer appliance to indicated a status of the appliance.
Appliances that may use the device include stoves and ovens (i.e., consumer ranges), washers, dryers, refrigerators, and/or any other appliance or machine that could utilize a musical tone notification device.
The charge time of the capacitor will cause a ramp-up in volume when AUDIO_TRIG goes high. This can be referred to as the “attack” time of the waveform as it is in music synthesizers. The attack time is set by the capacitor C4 and the resistor R8 in the circuit of
The discharge time of the capacitor will cause a ramp-down in volume when AUDIO TRIG goes low. This can be referred to as the “decay” time of the waveform as it is in music synthesizers. The decay time is set by selecting the values of the capacitor C4 and the resistor R5 in the circuit above. By varying such components in the circuit design, or providing a variable resistor and/or capacitor, the audio output attack and decay times can be modified or varied.
A “chime” is a waveform with a very quick attack time and a slow decay time. This is similar to when a person strikes a bell. The sound is heard at maximum volume instantly, and then it slowly decays until it is no longer heard. A chime sound can be produced by the circuit of
Waveforms with slow attack and decay times are similar to what is heard from a violin. By setting resistor R8, capacitor C4 and resistor R5 correctly, a sound very similar to a violin can be produced with this circuit. For Example, setting R8=20 k, C4=47 uF, and R5=1 k can provide such a sound.
The circuit can also produce a waveform with a slow attack and quick decay. This kind of sound is not naturally occurring, and can only be produced via musical synthesizers. However, this capability gives the device the ability to create some unique sounding tones, if desired.
In the current embodiment of the circuit of
However, the values of these components can be varied to obtain the desired sound effects, especially resistor R8, capacitor C4 and resistor R5, as described above. Furthermore, equivalents of the other components can be used as substitutes for those shown in the table.
By controlling the AUDIO_TRIG and AUDIO_WAV inputs, the circuit can be used to generate a plurality of pleasing melodies, each made up of a plurality of individual musical notes. The software routines of the Appendix are used to control the processor to produce the various melodies according to stored data for generating the various melodies.
In a current embodiment of the circuit of
Finally, the computer program listing appendix to this application contains two ASCII modules of “C” code for generating the chime melodies using a general purpose or dedicated microprocessor P2. For example, the program of the computer program listing can be compiled with a HiTech C Compiler, and a PIC18F452 processor can be used with one of the circuits of
Referring again to
The first software module is for providing functions to access a standard chime circuit. This module executes on a processor, providing a PWM output for the waveform generation and a standard I/O line output to trigger and hold the note, using one of the circuits shown above (or another equivalent circuit).
The module has a function that starts the chime. This function accepts: ChimeRequest, a Chime_t enumerated value that corresponds to the chime to be played. The module also has a function that is called on a period based on the timebase of the current chime being played. This function handles toggling all note signals.
The second module has tables with settings for each individual note based on an 8 MHz system clock. These tables have note and duration data for each “song” melody or tone that can be played. The first character of this array represents a time base which this chime will be played at. It is a multiple of the schedule tick. The 0xFF at the end of the array represents the end of the chime. Care should be taken that no other character in the array matches this number or the chime will end prematurely. In between these characters are the series of note data for the song. Each note consists of a 5 bit note value which refers to a position in the NoteTable array, and a 3 bit value which represents the duration of that note. The duration is the number of times through the scheduler loop to hold that note, and 1 is added to it automatically. Rests are called by referencing a 0 note value.
The parameters (song index including chime and note index) called by the software routine to play the song melody are stored in the device memory, which could be RAM, ROM, EEPROM, a hard drive, or another memory device or combination of devices, for example. Thus, a plurality of events can each be associated with a unique song melody, with the software routine calling the song parameters (i.e., the tempo of the song, and the frequency and duration of each note of the song) according to the triggering event.
If the song melody is not at the end, the routine checks to see if it is ready for a new note 111. If not, the routine returns to its start.
When ready for a new note, the routine sets the duration to OFF 114, increments the note index 115, loads the note duration and sets duration to ON 116, and checks to see if the note is a rest. If the note is a rest, no sound is played, and the routine returns to its start.
If the note is not a rest, the PWM registers are updated 119 with note frequency information, the PWM output is then activated 120, and note duration is decremented 121 and the routine returns to its start.
This routine is executed by the processor for each note of the song, and is called at a rate of 5 ms times the loaded tempo value. The tempo value can thus be used to control the melody tempo.
Referring again to
The processor executes the tone generation circuit in response to the status detection to play a melody associated with the detected status, to notify the user of the detected status of the device.
A plurality of different melodies can be stored (i.e., via the tone data stored in memory, as discussed above) with each melody being associated with a different status condition, for example. Alternatively, melody tempos might also be varied based on various status conditions. In this manner, the user can be notified of a specific detected status condition based on the melody played by the notification device.
In this manner, the user of the appliance is notified of various status conditions with one or more pleasing, musical melodies, rather than a harsh buzzer or bell.
The invention has been described hereinabove using specific examples; however, it will be understood by those skilled in the art that various alternatives may be used and equivalents may be substituted for elements or steps described herein, without deviating from the scope of the invention. Modifications may be necessary to adapt the invention to a particular situation or to particular needs without departing from the scope of the invention. It is intended that the invention not be limited to the particular implementation described herein, but that the claims be given their broadest interpretation to cover all embodiments, literal or equivalent, covered thereby.
This application claims the benefit of provisional application Ser. No. 60/551,553, filed on Mar. 9, 2004, incorporated herein by reference.
Number | Date | Country | |
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60551553 | Mar 2004 | US |