Hallo,

Ich versuche seit einiger Zeit das USART-Modul des PIC18F252 zu nutzen.
Ich möchte eine Kommunikation zwischen 2 PICs aufbauen.
Der Sende-PIC scheint dabei richtig zu funktionieren.
Mit dem Empfangen habe ich noch einige Probleme.
Ich programmiere mit C.
Kann mir da jemand helfen?


Das Sendeprogramm:

Code:
//Senden
#include <P18F252.h>

int ring;

void open_serial (void)
{
	// Configure UART serial transmit
        // Configured for:
	//  9600 Baud
	//  8N1
	                             
	// SPBRG - Baud Rate Generator Register
	SPBRG = 63; // 20MHz => 9600 baud (BRGH = 0)
	
	// BRGH - High Baud Rate Select Bit
	TXSTAbits.BRGH = 0; // (0 = low speed)
	
	// SYNC - USART Mode select Bit
	TXSTAbits.SYNC = 0; // (0 = asynchronous)
	
	// TRISC - Tri-state Data Direction Register for port C
	// RC6 - 6th pin of port C - used for Serial Transmit
	// RC7 - 7th pin of port C - used for Serial Receive
	TRISCbits.TRISC6 = 0; // (0 = pin set as output)
	TRISCbits.TRISC7 = 1; // (1 = pin set as input)
	
	// SPEN - Serial Port Enable Bit 
	RCSTAbits.SPEN = 1; // (1 = serial port enabled)

	// TXIE - USART Transmit Interupt Enable Bit
	PIE1bits.TXIE = 0; // (1 = enabled)

	// RCIE - USART Receive Interupt Enable Bit
	PIE1bits.RCIE = 0; // (1 = enabled)
	
	// TX9 - 9-bit Transmit Enable Bit
	TXSTAbits.TX9 = 0; // (0 = 8-bit transmit)
	
	// RX9 - 9-bit Receive Enable Bit
	RCSTAbits.RX9 = 0; // (0 = 8-bit reception)
	
	// CREN - Continuous Receive Enable Bit
	RCSTAbits.CREN = 0; // (1 = Enables receiver)
	
	// TXEN - Trasmit Enable Bit
	TXSTAbits.TXEN = 1; // (1 = transmit enabled)
	
	// GIE - Global Interrupt Enable Bit
	INTCONbits.GIE = 1; // (1 = Enable all unmasked interrupts)
	
	// PEIE - Peripheral Interrupt Enable Bit
	INTCONbits.PEIE = 1; // (1 = Enable all unmasked peripheral interrupts)
}

void wait (void)
{
int k;
for(k=0;k<5000;k++);
}

void main (void)
{
ADCON1 = 7;
LATA = 0x00;
TRISA = 0x00;
TRISB = 0xFF;
ring = 0;

	while(1)
	{	
	wait();
	open_serial();
	ring = PORTB;
	PORTA = ring;
		while(PIR1bits.TXIF)
		{
		TXREG = ring;
		}
	}
}
Das Empfangsprogramm:


Code:
//Empfangen
#include <P18F252.h>

void open_serial(void)
{
	// Configure UART serial transmit
        // Configured for:
	//  9600 Baud
	//  8N1
	                             
	// SPBRG - Baud Rate Generator Register
	SPBRG = 63; // 20MHz => 9600 baud (BRGH = 0)
	
	// BRGH - High Baud Rate Select Bit
	TXSTAbits.BRGH = 1; // (0 = low speed)
	
	// SYNC - USART Mode select Bit
	TXSTAbits.SYNC = 0; // (0 = asynchronous)
	
	// TRISC - Tri-state Data Direction Register for port C
	// RC6 - 6th pin of port C - used for Serial Transmit
	// RC7 - 7th pin of port C - used for Serial Receive
	TRISCbits.TRISC6 = 0; // (0 = pin set as out)
	TRISCbits.TRISC7 = 1; // (1 = pin set as input)
	
	// SPEN - Serial Port Enable Bit 
	RCSTAbits.SPEN = 1; // (1 = serial port enabled)

	// TXIE - USART Transmit Interupt Enable Bit
	PIE1bits.TXIE = 0; // (1 = enabled)

	// RCIE - USART Receive Interupt Enable Bit
	PIE1bits.RCIE = 1; // (1 = enabled)
	
	// TX9 - 9-bit Transmit Enable Bit
	TXSTAbits.TX9 = 0; // (0 = 8-bit transmit)
	
	// RX9 - 9-bit Receive Enable Bit
	RCSTAbits.RX9 = 0; // (0 = 8-bit reception)
	
	// CREN - Continuous Receive Enable Bit
	RCSTAbits.CREN = 1; // (1 = Enables receiver)
	
	// TXEN - Trasmit Enable Bit
	TXSTAbits.TXEN = 0; // (1 = transmit enabled)
	// GIE - Global Interrupt Enable Bit
	INTCONbits.GIE = 0; // (1 = Enable all unmasked interrupts)
	
	// PEIE - Peripheral Interrupt Enable Bit
	INTCONbits.PEIE = 1; // (1 = Enable all unmasked peripheral interrupts)
}

void main (void) 
{
TRISB = 0x00;
PORTB = 0b01010101;
RCREG = 0;
open_serial();

	while(1)
	{	
		if(PIR1bits.RCIF == 1)
		{
		PORTB = RCREG;
		PIR1bits.RCIF = 0;
		}
	}
}
Danke für die Hilfe. mfg Adonai