PIC18LF4680 und USB TTL für usart / serielle Kommunikation

Ich möchte wissen, ob es möglich ist, ein TTL-Gerät für die serielle Kommunikation über USART direkt an meinen PIC18LF4680 anzuschließen. Ich kann das ttl-Gerät ohne Probleme direkt an meinen Arduino Uno anschließen. Das ist meine Hardware:

Das TTL-Gerät hat 6 Pins (dtr , rxd , txd , vcc(3.3v oder 5v) , cts, gnd) .

Ich habe unten zwei verschiedene Code-Snippets, die die USART-Kommunikation durchführen.

Version eins (I) verwendet die Peripheriebibliothek "usart.h". Version zwei (II) verwendet "TXREG" und "RCREG" zum Senden und Empfangen von Daten.

Beide Versionen laufen gut in meiner virtuellen Umgebung (proteus 8 professional), aber nicht in der realen Umgebung. Übersehe ich einen Schritt? Brauche ich eine spezielle Bibliothek? Oder geht das mit diesem Chip nicht?

Version I ---------------------------------------

#include "fuses.h"
#include <p18lf4680.h>
#include <stdio.h>
#include <stdlib.h>
#include <plib/usart.h>


void main(void) {

    TRISB = 0x00;
    OSCCON = 0x76;          // 8mhz (0111 0110)

     LATBbits.LATB4 = 0; 
    LATBbits.LATB1 = 0; 
    LATBbits.LATB0 = 0; 

    unsigned char txt1[] = "Hello World \r\n";
    unsigned char txt2[] = "Enter a number.... \r\n";

    CloseUSART();

    OpenUSART(USART_TX_INT_OFF &
            USART_RX_INT_OFF &
            USART_ASYNCH_MODE &
            USART_EIGHT_BIT &
            USART_CONT_RX &
            USART_BRGH_HIGH &
            USART_ADDEN_OFF ,
            52);


    for(int x=0;x<=20;x++){__delay_ms(50);}

    // write/send intro to PC

    while(BusyUSART());
    putsUSART((char *)txt1);

    for(int x=0;x<20;x++){__delay_ms(50);}

    while(BusyUSART());
    putsUSART((char *)txt2);

    for(int x=0;x<20;x++){__delay_ms(50);}


    while(1){
        sdata = ReadUSART();

        switch(sdata){
            case '1':
                LATBbits.LATB4 = 1; 
                LATBbits.LATB1 = 0; 
                LATBbits.LATB0 = 0;

            break;

            case '2':
                LATBbits.LATB4 = 0;
                LATBbits.LATB1 = 1; 
                LATBbits.LATB0 = 0; 

            break;

            case '3':
                LATBbits.LATB4 = 0; 
                LATBbits.LATB1 = 0; 
                LATBbits.LATB0 = 1; 

            break;


            default:
                LATBbits.LATB4 = 0;
                LATBbits.LATB1 = 0;
                LATBbits.LATB0 = 0; 


            break;
        }
    }

}

-------------------------------------------------- --- Variante II---------------------------------------------------

#include "fuses.h"
#include <p18lf4680.h>
#include <stdio.h>
#include <stdlib.h>

#define STRLEN 12

volatile unsigned char t;
volatile unsigned char rcindex;
volatile unsigned char rcbuf[STRLEN];

void USART_init(void){

    TXSTAbits.TXEN = 1;     // enable transmitter
    TXSTAbits.BRGH = 1;     // high baud rate mode
    RCSTAbits.CREN = 1;     // enable continous receiving

    // configure I/O pins
    TRISCbits.TRISC7 = 1;     // RX pin is input
    TRISCbits.TRISC6 = 1;     // TX pin is input (automatically configured)

    SPBRG = 52;            

    PIE1bits.RCIE = 1;      // enable USART receive interrupt
    RCSTAbits.SPEN = 1;     // enable USART


}

void USART_putc(unsigned char c)
{
    while (!TXSTAbits.TRMT); // wait until transmit shift register is empty
    TXREG = c;               // write character to TXREG and start transmission
}

void USART_puts(unsigned char *s)
{
    while (*s)
    {
        USART_putc(*s);     // send character pointed to by s
        s++;                // increase pointer location to the next character
    }
}

void main(void) {

    OSCCON = 0x76;          // 8mhz (0111 0110)

    USART_init();

    USART_puts("Init complete! \n");

    INTCONbits.PEIE = 1;    // enable peripheral interrupts
    INTCONbits.GIE = 1;     // enable interrupts

    while(1)
    {

    }

}

void interrupt ISR(void)
{
    if (PIR1bits.RCIF)  // check if receive interrupt has fired
    {
        t = RCREG;      // read received character to buffer

        // check if received character is not new line character
        // and that maximum string length has not been reached
        if ( (t != '\n') && (rcindex < STRLEN) )
        {
            rcbuf[rcindex] = t; // append received character to string
            rcindex++;          // increment string index
        }
        else
        {
            rcindex = 0;        // reset string index
            USART_puts(rcbuf);  // echo received string
        }

        PIR1bits.RCIF = 0;      // reset receive interrupt flag
    }
}

Jede Hilfe wird geschätzt. Danke!