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(PIC 18F2550 ---- Xtal 8Mhz)

sbit LCD_RS at RA5_bit;
sbit LCD_EN at RA4_bit;
sbit LCD_D4 at RA0_bit;
sbit LCD_D5 at RA1_bit;
sbit LCD_D6 at RA2_bit;
sbit LCD_D7 at RA3_bit;

sbit LCD_RS_Direction at TRISA5_bit;
sbit LCD_EN_Direction at TRISA4_bit;
sbit LCD_D4_Direction at TRISA0_bit;
sbit LCD_D5_Direction at TRISA1_bit;
sbit LCD_D6_Direction at TRISA2_bit;
sbit LCD_D7_Direction at TRISA3_bit;

char texto2[10], texto1[]="Data Receiver";

unsigned char rxdat[10]; // (global var) holds received RF bytes

//=============================================================================
// RECEIVE_RF_PACKET
//=============================================================================
void main(void)
{
//-------------------------------------------------------
// This function receives an RF packet of bytes in my pulse period
// encoded format. The packet must have 10 valid contiguous bytes
// or the function will not exit. There is no timeout feature, but could be added.
// global variable; unsigned char rxdat[10] holds the 10 byte result.
// Note! TMR0 is running at 500kHz, so 200uS = 100 TMR0 ticks
//-------------------------------------------------------
unsigned char rrp_data;
unsigned char rrp_period;
unsigned char rrp_bits;
unsigned char rrp_bytes;

TRISC.RC6 = 0; // TX pin, works fine with/without setting this I/O in proteus
TRISC.RC7 = 1; // RX pin, works fine with/without setting this I/O in proteus
CMCON = 0x07;
ADCON1 = 0x0F;
Lcd_Init(); //Inicializa el LCD.
Lcd_Cmd(_LCD_CLEAR); //Borra el display.
Lcd_Cmd(_LCD_CURSOR_OFF); //Apaga el cursor.
Lcd_Out(1,6,texto1); //Escribe el texto1.

rrp_bytes = 0;
while(rrp_bytes < 10) // loop until it has received 10 contiguous RF bytes
{
//-----------------------------------------
// wait for a start pulse >200uS
while(1)
{
while(!PORTC.F7) continue; // wait for input / edge
while(PORTC.F7) continue; // wait for input \ edge
rrp_period = TMR0L; // grab the pulse period!
TMR0L = 0; // and ready to record next period
if(rrp_period < 100) rrp_bytes = 0; // clear bytecount if still receiving noise
else break; // exit if pulse was >200uS
}

//-----------------------------------------
// now we had a start pulse, record 8 bits
rrp_bits = 8;
while(rrp_bits)
{
while(!PORTC.F7) continue; // wait for input / edge
while(PORTC.F7) continue; // wait for input \ edge
rrp_period = TMR0L; // grab the pulse period!
TMR0L = 0; // and ready to record next period

if(rrp_period >= 100) break; // if >=200uS, is unexpected start pulse!

if(rrp_period < 61) rrp_data.F0 = 0; // 61 = 122uS
else rrp_data.F0 = 1;
rrp_data = (rrp_data << 1); // save the good bit into rrp_data
rrp_bits--; // and record 1 more good bit done
}

//-----------------------------------------
// gets to here after 8 good bits OR after an error (unexpected start pulse)
if(rrp_bits) // if error
{
rrp_bytes = 0; // reset bytes, must run from start of a new packet again!
}
else // else 8 good bits were received
{
rxdat[rrp_bytes] = rrp_data; // so save the received byte into array
rrp_bytes++;
// record another good byte was saved


bytetohex(rrp_data,texto2);
lcd_out(2,1,texto2);
delay_ms(50);

}
}
}
//-----------------------------------------------------------------------------

{
   //-----------------------------------------
   // wait for a start pulse >200uS
   while(1)
   {
     while(!PORTC.F7) continue;    // wait for input / edge
     while(PORTC.F7) continue;     // wait for input \ edge
     rrp_period = TMR0L;           // grab the pulse period!
     TMR0L = 0;                    // and ready to record next period
     if(rrp_period < 100) rrp_bytes = 0;   // clear bytecount if still receiving noise
     else break;                   // exit if pulse was >200uS
   }