// PIN ASSIGNMENT //
sbit DATA_INT = P3^0;
sbit KB_DATA = P3^2;
sbit EN = P3^4;
sbit RS = P3^5;

// PROTOTYPES //
// LCD functions //
void lcd_delay(bit length);
void write_char(char character);
void write_message(char * message);
void clear_disp();
void lcd_initialize();
void monitor_lcd_line(signed char amt);

// Keyboard functions //
//bit calc_parity(char tmp);
void kb_machine(char * kb_arr);
char conv_to_ascii(char scan_code);

// Output functions //
char conv_to_send_protocol(char ascii_code);
void output_data(char scode);

// General functions //
char pow(char num, char pow);
int strlen(char * string);
void sec_delay(int sec);

// GLOBAL VARIABLES //
char output_buffer[49],output_buffer_counter=0,char_count=0;

#include <intrins.h>

/* LCD functions */
void lcd_delay(bit length)
{
// length = 1 -> 1.64ms
// length = 0 -> 40us
int count_size = (length == 1) ? 3280 : 80;

TH0 = ~(count_size/256);
TL0 = -(count_size%256);

TR0 = 1;
while(!TF0);
TF0 = 0;
TR0 = 0;
}

void monitor_lcd_line(signed char amt)
{
// break line automatically
if(char_count<24 && (char_count+amt)>=24)
{
RS = 0;
P1 = 0xc0;
EN = 1;
EN = 0;
lcd_delay(0);
char_count+=amt;
}
else
{
char_count+=amt;
}
}

void write_char(char character)
{
RS = 1;
P1 = character;
EN = 1;
EN = 0;
lcd_delay(0);
monitor_lcd_line(+1);
}

void write_message(char * message)
{
char i;

clear_disp();
for(i=0; i<strlen(message); i++)
write_char(message[i]);
}

void clear_disp()
{
RS = 0;
P1 = 0x01;
EN = 1;
EN = 0;
lcd_delay(1);
char_count=0;
}

void lcd_initialize()
{
// function set
RS = 0;
P1 = 0x38;
EN = 1;
EN = 0;
lcd_delay(0);
// entry mode set
RS = 0;
P1 = 0x06;
EN = 1;
EN = 0;
lcd_delay(0);
// display control
RS = 0;
P1 = 0x0e;
EN = 1;
EN = 0;
lcd_delay(0);
// clear display
RS = 0;
P1 = 0x01;
EN = 1;
EN = 0;
lcd_delay(1);
}



/* KB functions */

void INT1_ISR() interrupt 2
{
static char i=0;
static char in_data[33];

in_data[i] = KB_DATA;
i++;
if(i==33)
{
kb_machine(in_data);
i=0;
}
}

/*bit calc_parity(char tmp)
{
// calculate odd parity = NOT(XOR(D0...D7))
char i;
bit xor;
for(i=0; i<8; i++)
{
tmp = tmp>>i;
xor = xor^tmp&0x01;
}
return ~xor;
}*/

void kb_machine(char * kb_arr)
{
char scan_code=0,ascii_code,i=0;
static bit del_start_msg=0;

if(!del_start_msg) { clear_disp(); del_start_msg=1; }

for(i=1; i<9; i++)
scan_code = scan_code + kb_arr[i]*pow(2,i-1);

if(scan_code == 0x5a) // user pressed on ENTER, send out!
{
output_buffer[output_buffer_counter] = 0xff;
EA = 0; // disable KB
write_message("KB will not be available during transmission.");
for(i=0; i<=output_buffer_counter; i++) output_data(output_buffer[i]);
clear_disp();
write_message("Success. You can type a new message if you like.");
sec_delay(10);
clear_disp();
EA = 1; // enable KB
output_buffer_counter=0;

}
/* else if(is_effect(scan_code))
{
output_data(conv_to_send_protocol(scan_code));
}*/
else if(scan_code == 0x66) // delete last char
{

if(char_count!=24)
{
output_buffer[--output_buffer_counter] = 0;
// move cursor one char back
RS = 0;
P1 = 0x10;
EN = 1;
EN = 0;
lcd_delay(0);
// write space (delete effect)
RS = 1;
P1 = ' ';
EN = 1;
EN = 0;
lcd_delay(0);
// move cursor back to its place.
RS = 0;
P1 = 0x10;
EN = 1;
EN = 0;
lcd_delay(0);
monitor_lcd_line(-1);
}
else
{
output_buffer[--output_buffer_counter] = 0;
// go back to end of second line
RS = 0;
P1 = 0x97;
EN = 1;
EN = 0;
lcd_delay(0);
// write space (delete effect)
RS = 1;
P1 = ' ';
EN = 1;
EN = 0;
lcd_delay(0);
// move cursor back to its place.
RS = 0;
P1 = 0x10;
EN = 1;
EN = 0;
lcd_delay(0);
/*RS = 0;
P1 = 0x10;
EN = 1;
EN = 0;
lcd_delay(0);*/
monitor_lcd_line(-1);
}
}
else
{
ascii_code = conv_to_ascii(scan_code);
if(ascii_code!=0 && char_count<48)
{
write_char(ascii_code); // write to lcd
output_buffer[output_buffer_counter++] = conv_to_send_protocol(ascii_code);
}
}
}

char conv_to_ascii(char scan_code)
{
switch(scan_code)
{
case 0x1c: return 'A';
case 0x32: return 'B';
case 0x21: return 'C';
case 0x23: return 'D';
case 0x24: return 'E';
case 0x2b: return 'F';
case 0x34: return 'G';
case 0x33: return 'H';
case 0x43: return 'I';
case 0x3b: return 'J';
case 0x42: return 'K';
case 0x4b: return 'L';
case 0x3a: return 'M';
case 0x31: return 'N';
case 0x44: return 'O';
case 0x4d: return 'P';
case 0x15: return 'Q';
case 0x2d: return 'R';
case 0x1b: return 'S';
case 0x2c: return 'T';
case 0x3c: return 'U';
case 0x2a: return 'V';
case 0x1d: return 'W';
case 0x22: return 'X';
case 0x35: return 'Y';
case 0x1a: return 'Z';
case 0x29: return ' ';
case 0x16: return '1';
case 0x1e: return '2';
case 0x26: return '3';
case 0x25: return '4';
case 0x2e: return '5';
case 0x36: return '6';
case 0x3d: return '7';
case 0x3e: return '8';
case 0x46: return '9';
case 0x45: return '0';
case 0x4e: return '-';
default: return 0;
}
}

/* Output functions */
void output_data(char scode)
{
DATA_INT = 0;
SBUF = scode;
while(!TI); // wait till end of transmission
TI = 0;
DATA_INT = 1;
}

char conv_to_send_protocol(char ascii_code)
{
switch(ascii_code)
{
case 'A': return 0;
case 'B': return 1;
case 'C': return 2;
case 'D': return 3;
case 'E': return 4;
case 'F': return 5;
case 'G': return 6;
case 'H': return 7;
case 'I': return 8;
case 'J': return 9;
case 'K': return 10;
case 'L': return 11;
case 'M': return 12;
case 'N': return 13;
case 'O': return 14;
case 'P': return 15;
case 'Q': return 16;
case 'R': return 17;
case 'S': return 18;
case 'T': return 19;
case 'U': return 20;
case 'V': return 21;
case 'W': return 22;
case 'X': return 23;
case 'Y': return 24;
case 'Z': return 25;
case ' ': return 26;
case '0': return 27;
case '1': return 28;
case '2': return 29;
case '3': return 30;
case '4': return 31;
case '5': return 32;
case '6': return 33;
case '7': return 34;
case '8': return 35;
case '9': return 36;
case '-': return 37;
case 0x05: return 0xe0;
case 0x06: return 0xe1;
case 0x04: return 0xe2;
case 0x0c: return 0xe3;
}
}

/* General functions */

char pow(char num, char pow)
{
char tmp=1,i;
for(i=0; i<pow; i++)
tmp *= num;
return tmp;
}

int strlen(char * string)
{
char i=0;
while(1)
{
if(string[i]!=0) i++;
else break;
}
}

void sec_delay(int sec)
{
int i;

TMOD = 0x09; // timer 0 mode 1

for(i=0; i<20*sec; i++)
{
TH0 = ~(50000/256);
TL0 = -(50000%256);

TR0 = 1;
while(!TF0);
TF0 = 0;
TR0 = 0;
}
}


// main
void main()
{
lcd_initialize(); // lcd initialization
write_message("Welcome, please type in your message.");

IE = 0x84; // enable INT1
IT1 = 1;
// output options //
SCON = 0x40; // Mode 1, No Parity
TMOD = 0x21; // T1 Mode 2 (auto reload - baud gen). T0 Mode 1 (general use).
TH1 = -26;
TR1 = 1;
//T2CON = 0x34;
//PCON=PCON|0x80; // smod = 1
//RCAP2H = ~(40000/256); // 2400 baud rate
//RCAP2H = -(40000%256);
//TR2 = 1;
DATA_INT = 1; // idle

while(1);
}