' Name        : TONEX.pbp
' Compiler    : PICBASIC PRO Compiler 2.6
' Assembler   : PM or MPASM
' Target PIC  : 40-pin 16F877 or similar
' Hardware    : LAB-X1 Experimenter Board
' Oscillator  : 20MHz
' Keywords    : DCD, DTMFOUT, LCDOUT, LOOKUP, NCD
' Description : PICBASIC PRO program to create telephone pad tone.
' Note: LAB-X1 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

Define OSC 20

' Define LCD connections
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 on LAB-X1 board

   OPTION_REG.7 = 0  ' Enable PORTB pullups
   ADCON1 = 7        ' 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
       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