' Name        : TONEXU.pbp
' Compiler    : PICBASIC PRO Compiler 2.6
' Assembler   : MPASM
' Target PIC  : PIC18F4550 or similar type
' Hardware    : LAB-XUSB Experimenter Board
' Oscillator  : 20MHz external
' Keywords    : DCD, DTMFOUT, LCDOUT, LOOKUP, NCD
' Description : PICBASIC PRO program to create telephone pad tone.
' Oscillator must be set to 20MHz.
'

' Define LOADER_USED to allow use of the boot loader.
' This will not affect normal program operation.
Define LOADER_USED 1

' RESET_ORG can be set to move the BASIC program out of the way
' of any boot loader running from location 0, such as the
' Microchip USB boot loader
'Define RESET_ORG 800h

Define OSC 48      ' Core is running at 48MHz

' Define LCD pins
Define LCD_DREG  PORTD
Define LCD_DBIT  4
Define LCD_RSREG PORTE
Define LCD_RSBIT 0
Define LCD_EREG  PORTE
Define LCD_EBIT  1

' Define program variables
col  Var Byte     ' Keypad column
row  Var Byte     ' Keypad row
key  Var Byte     ' Key value
tone Var Byte     ' Tone number
spkr Var PORTC.2  ' Alias speaker pin

   INTCON2.7 = 0           ' Enable PORTB pullups
   ADCON1 = 15             ' Make PORTA and PORTE digital
   Low PORTE.2             ' LCD R/W low (write)
   Pause 100               ' Wait for LCD to start
   Lcdout $fe, 1, "Press any key"  ' Display sign on message

mainloop:
   Gosub getkey            ' Get a key from the keypad
   Lookup tone,["0123456789*#ABCD"],key
   Lcdout $fe, 1, key      ' Display ASCII key number
   Dtmfout spkr, [tone]
   Goto mainloop           ' Do it forever

' Subroutine to get a key from keypad
getkey:
   Pause 50                ' Debounce

getkeyu:
   ' Wait for all keys up
   PORTB = 0               ' All output pins low
   TRISB = $f0             ' Bottom 4 pins out, top 4 pins in
   If ((PORTB >> 4) != $f) Then getkeyu ' If any keys down, loop
   Pause 50                ' Debounce

getkeyp:
   ' Wait for keypress
   For col = 0 to 3        ' 4 columns in keypad
     PORTB = 0             ' All output pins low
     TRISB = (dcd col) ^ $ff ' Set one column pin to output
     Pauseus 1
     row = PORTB >> 4      ' Read row
     If row != $f Then gotkey ' If any keydown, exit
   Next col
   Goto getkeyp            ' No keys down, go look again

gotkey: ' Change row and column to key number 0 - 15
   key = (col * 4) + (ncd (row ^ $f)) - 1

   ' Translate key to telephone keypad tone
   ' 10 = *
   ' 11 = #
   ' 12 = A
   ' 13 = B
   ' 14 = C
   ' 15 = D
   Lookup key,[1,2,3,12,4,5,6,13,7,8,9,14,10,0,11,15],tone
   Return                  ' Subroutine over

   End