REM ****************************************************************
REM ** Audio Demonstration on Raspberry Pi Pico with MMBasic      **
REM ** Steve Johnson   March 10, 2023   Newbury Park, California  **
REM **                                                            **
REM ** Requires running the following from command line once:     **
REM **    OPTION AUDIO GP0, GP1 and OPTION POWER PWM              **
REM ** Connect speaker leads to GP0 and GP1. No GND connection.   **
REM ****************************************************************
REM These data statements contain the frequencies for well-tuned notes
DATA 32.70,  65.41, 130.81, 261.63, 523.25, 1046.50, 2093.00, 4186.01 'C nat
DATA 34.65,  69.30, 138.59, 277.18, 554.37, 1108.73, 2217.46, 4434.92 'C#
DATA 36.71,  73.42, 146.83, 293.66, 587.33, 1174.66, 2349.32, 4698.64 'D nat
DATA 38.89,  77.78, 155.56, 311.13, 622.25, 1244.51, 2489.02, 4978.03 'D#
DATA 41.20,  82.41, 164.81, 329.63, 659.26, 1318.51, 2637.02, 5274.04 'E nat
DATA 43.65,  87.31, 174.61, 349.23, 698.46, 1396.91, 2793.83, 5587.65 'F nat
DATA 46.25,  92.50, 185.00, 369.99, 739.99, 1479.98, 2959.96, 5919.91 'F#
DATA 49.00,  98.00, 196.00, 392.00, 783.99, 1567.98, 3135.96, 6271.93 'G nat
DATA 51.91, 103.83, 207.65, 415.30, 830.61, 1661.22, 3322.44, 6644.88 'G#
DATA 55.00, 110.00, 220.00, 440.00, 880.00, 1760.00, 3520.00, 7040.00 'A nat
DATA 58.27, 116.54, 233.08, 466.16, 932.33, 1864.66, 3729.31, 7458.62 'A#
DATA 61.74, 123.47, 246.94, 493.88, 987.77, 1975.53, 3951.07, 7902.13 'B nat

DIM FLOAT Tuning(8, 12)
DIM INTEGER Octave, Note, Delay=50

FOR Note=1 To 12 : FOR Octave=1 To 8
 Read Tuning(Octave, Note)
NEXT  Octave : NEXT  Note

DO
 FOR Octave = 4 To 8 : FOR Note = 1 To 12
   PLAY TONE Tuning(Octave, Note), Tuning(12-Octave, 13-Note) : PAUSE Delay
 NEXT  Note : NEXT  Octave
LOOP
PLAY STOP

REM ***********************************************************************
REM **                                                                   **
REM **  DTMF Demonstration on Raspberry Pi Pico with MMBasic             **
REM **                                                                   **
REM ** Steve Johnson   March 12, 2023   Newbury Park, California         **
REM **                                                                   **
REM ** https://en.wikipedia.org/wiki/Dual-tone_multi-frequency_signaling **
REM ** Requires running the following from command line once:            **
REM **    OPTION AUDIO GP0, GP1 and OPTION POWER PWM                     **
REM ** Connect speaker leads to GP0 and GP1. No GND connection           **
REM ** Hold the speaker near the phone mouthpiece.                       **
REM ***********************************************************************

REM These data contain the frequencies for the DTMF tones
DATA 697, 770, 852, 941, 1209, 1336, 1477, 1633

REM These data contain the combination indices for pairs of tones
REM from 0-9, *, #, A, B, C, and D

DATA "0", 4, 6, "1", 1, 5, "2", 1, 6, "3", 1, 7, "4", 2, 5
DATA "5", 2, 6, "6", 2, 7, "7", 3, 5, "8", 3, 6, "9", 3, 7
DATA "*", 4, 5, "#", 4, 7
DATA "A", 1, 8, "B", 2, 8, “C", 3, 8, "D", 4, 8

DIM FLOAT Tones(8), Tone
DIM INTEGER Row, Column, Dtmf(16,2), Code
DIM INTEGER Digit_Dur=175, Digit_Pause=50, Comma_Pause=500, Dash_Pause=100
DIM STRING Symbol(16), Phone_Number, Digit
DIM INTEGER Debug = 0

SUB  Load_DTMF
 FOR Tone = 1 To 8 : Read Tones(Tone) : NEXT Tone
 FOR Code = 1 To 16
   Read Symbol(Code), Dtmf(Code, 1), Dtmf(Code, 2)
 NEXT Code
END SUB

SUB  Dial_Phone Phone_Number As STRING
 IF Debug=1 THEN PRINT "Dialing "; Phone_Number
 FOR i = 1 To Len(Phone_Number)
   Dial_Digit Mid$(Phone_Number, i, 1)
 NEXT i
END SUB

SUB  Dial_Digit Digit As STRING
 IF Digit = "," THEN
   PAUSE Comma_Pause
 ELSEIF Digit = "-" THEN
   PAUSE Dash_Pause
 ELSE
   FOR Code = 1 To 16
     IF Digit = Symbol(Code) THEN
       Row = Dtmf(Code,1) : Column = Dtmf(Code,2)
       IF Debug=1 THEN
         PRINT Digit; Row; " ("; Tones(Row); "), ";
         PRINT Column;" ("; Tones(Column);")"
       ENDIF
       PLAY TONE Tones(Row), Tones(Column) : PAUSE Digit_Dur
       PLAY STOP : PAUSE Digit_Pause
     ENDIF
   NEXT Code
 ENDIF
END SUB

REM ************************************************************************
REM ** Main Loop                                                          **
REM ************************************************************************

Load_DTMF
Dial_Phone "1,805-555-1212"