'Morse Code demonstration for Great Cow BASIC
'(c) Hugh Considine 2006-2008

'A program to accept messages from a standard PS/2 keyboard, then play
'them as morse code using a speaker.

'User Settings
#define CodeFrequency 750 'Hz
#define DotLength 5 '* 10 ms
#define DotSpace 250 ' ms
#define BarLength 25 '* 10 ms
#define BarSpace 50 ' ms

'Hardware settings
#chip 16F877A, 20

'LCD connection settings
#define LCD_IO 8
#define LCD_DATA_PORT PORTC
#define LCD_RS PORTD.0
#define LCD_RW PORTD.1
#define LCD_Enable PORTD.2

'PS/2 keyboard connection settings
#define PS2Clock PORTB.1
#define PS2Data PORTB.2

'Tone output pin
#define SoundOut PORTD.3

'Set port directions
DIR PS2Clock IN
DIR PS2Data IN
DIR SoundOut OUT

'Clear key buffer
DIM KeyLog(32)
DataCount = 0
KeyLog(1) = 32 'Space character

'Show opening message
PRINT "GCBASIC Morse"
locate 1,0
PRINT "Code Transmitter"

'Main routine
Main:

'Get a keypress
KeyIn = INKEY
if KeyIn = 0 then goto Main

'Allow time for key to be released
wait 150 ms

'if ENTER is pressed, then send message
if KeyIn = 13 then
MorseSend
goto Main
end if

'Escape - clear message buffer
if KeyIn = 27 then
DataCount = 0
for DataPos = 1 to 32
KeyLog(DataPos) = 32
next
goto DisplayData
end if

'Backspace - delete last character
if KeyIn = 8 then
if DataCount = 0 then goto Main
KeyLog(DataCount) = 32
DataCount = DataCount - 1
goto DisplayData
end if

'Otherwise, add the character to the buffer
DataCount = DataCount + 1
KeyLog(DataCount) = KeyIn

DisplayData:
'Display key log
CLS
for DataPos = 1 to DataCount
if DataPos = 17 then locate 1,0
LCDWriteChar KeyLog(DataPos)
next

goto Main

sub MorseSend
for SendLetter = 1 to DataCount
Letter = KeyLog(SendLetter)

'Numbers
if Letter = 48 then Bar: Bar: Bar: Bar: Bar '0
if Letter = 49 then Dot: Bar: Bar: Bar: Bar '1
if Letter = 50 then Dot: Dot: Bar: Bar: Bar '2
if Letter = 51 then Dot: Dot: Dot: Bar: Bar '3
if Letter = 52 then Dot: Dot: Dot: Dot: Bar '4
if Letter = 53 then Dot: Dot: Dot: Dot: Dot '5
if Letter = 54 then Bar: Dot: Dot: Dot: Dot '6
if Letter = 55 then Bar: Bar: Dot: Dot: Dot '7
if Letter = 56 then Bar: Bar: Bar: Dot: Dot '8
if Letter = 57 then Bar: Bar: Bar: Bar: Dot '9

'Letters
if Letter >= 97 and Letter <= 122 then Letter -= 32 'Convert to upper case
if Letter = 65 then Dot: Bar
if Letter = 66 then Bar: Dot: Dot: Dot
if Letter = 67 then Bar: Dot: Bar: Dot
if Letter = 68 then Bar: Dot: Dot
if Letter = 69 then Dot
if Letter = 70 then Dot: Dot: Bar: Dot
if Letter = 71 then Bar: Bar: Dot
if Letter = 72 then Dot: Dot: Dot: Dot
if Letter = 73 then Dot: Dot 'I
if Letter = 74 then Dot: Bar: Bar: Bar 'J
if Letter = 75 then Bar: Dot: Bar 'K
if Letter = 76 then Dot: Bar: Dot: Dot 'L
if Letter = 77 then Bar: Bar 'M
if Letter = 78 then Bar: Dot 'N
if Letter = 79 then Bar: Bar: Bar 'O
if Letter = 80 then Dot: Bar: Bar: Dot 'P
if Letter = 81 then Bar: Bar: Dot: Bar 'Q
if Letter = 82 then Dot: Bar: Dot 'R
if Letter = 83 then Dot: Dot: Dot 'S
if Letter = 84 then Bar 'T
if Letter = 85 then Dot: Dot: Bar 'U
if Letter = 86 then Dot: Dot: Dot: Bar 'V
if Letter = 87 then Dot: Bar: Bar 'W
if Letter = 88 then Bar: Dot: Dot: Bar 'X
if Letter = 89 then Bar: Dot: Bar: Bar 'Y
if Letter = 90 then Bar: Bar: Dot: Dot 'Z

'Misc
if Letter = 32 then wait 300 ms 'Space
next
end sub

sub Dot
Tone CodeFrequency, DotLength
wait DotSpace ms
end sub

sub Bar
Tone CodeFrequency, BarLength
wait BarSpace ms
end sub