Estoy usando un cable FTDI y lo conecté con mi mac. Puedo conectarme exitosamente con mi terminal serial en mi mac a través del cable y puedo ingresar texto en mi teclado para ser transmitido al AVR. Cuando se inicie el programa, espero que aparezca un mensaje "Hello World" en mi terminal serial. Pero en cambio recibo esta salida en la pantalla:
introduceladescripcióndelaimagenaquí
Elcódigoeseste:
//-------Preamble--------//#include<avr/io.h>#include<util/delay.h>#include"pinDefines.h"
#include "USART.h"
int main(void) {
char serialCharacter;
// -------- Inits --------- //
LED_DDR = 0xff; /* set up LEDs for output */
initUSART();
printString("Hello World!\r\n"); /* to test */
// ------ Event loop ------ //
while (1) {
serialCharacter = receiveByte();
transmitByte(serialCharacter);
LED_PORT = serialCharacter;
/* display ascii/numeric value of character */
} /* End event loop */
return 0;
}
El archivo USART.c contiene:
#include <avr/io.h>
#include "USART.h"
#include <util/setbaud.h>
#define BAUD 9600
void initUSART(void) { /* requires BAUD */
UBRR0H = UBRRH_VALUE; /* defined in setbaud.h */
UBRR0L = UBRRL_VALUE;
#if USE_2X
UCSR0A |= (1 << U2X0);
#else
UCSR0A &= ~(1 << U2X0);
#endif
/* Enable USART transmitter/receiver */
UCSR0B = (1 << TXEN0) | (1 << RXEN0);
UCSR0C = (1 << UCSZ01) | (1 << UCSZ00); /* 8 data bits, 1 stop bit */
}
void transmitByte(uint8_t data) {
/* Wait for empty transmit buffer */
loop_until_bit_is_set(UCSR0A, UDRE0);
UDR0 = data; /* send data */
}
uint8_t receiveByte(void) {
loop_until_bit_is_set(UCSR0A, RXC0); /* Wait for incoming data */
return UDR0; /* return register value */
}
/* Here are a bunch of useful printing commands */
void printString(const char myString[]) {
uint8_t i = 0;
while (myString[i]) {
transmitByte(myString[i]);
i++;
}
}
void readString(char myString[], uint8_t maxLength) {
char response;
uint8_t i;
i = 0;
while (i < (maxLength - 1)) { /* prevent over-runs */
response = receiveByte();
transmitByte(response); /* echo */
if (response == '\r') { /* enter marks the end */
break;
}
else {
myString[i] = response; /* add in a letter */
i++;
}
}
myString[i] = 0; /* terminal NULL character */
}
void printByte(uint8_t byte) {
/* Converts a byte to a string of decimal text, sends it */
transmitByte('0' + (byte / 100)); /* Hundreds */
transmitByte('0' + ((byte / 10) % 10)); /* Tens */
transmitByte('0' + (byte % 10)); /* Ones */
}
void printWord(uint16_t word) {
transmitByte('0' + (word / 10000)); /* Ten-thousands */
transmitByte('0' + ((word / 1000) % 10)); /* Thousands */
transmitByte('0' + ((word / 100) % 10)); /* Hundreds */
transmitByte('0' + ((word / 10) % 10)); /* Tens */
transmitByte('0' + (word % 10)); /* Ones */
}
void printBinaryByte(uint8_t byte) {
/* Prints out a byte as a series of 1's and 0's */
uint8_t bit;
for (bit = 7; bit < 255; bit--) {
if (bit_is_set(byte, bit))
transmitByte('1');
else
transmitByte('0');
}
}
char nibbleToHexCharacter(uint8_t nibble) {
/* Converts 4 bits into hexadecimal */
if (nibble < 10) {
return ('0' + nibble);
}
else {
return ('A' + nibble - 10);
}
}
void printHexByte(uint8_t byte) {
/* Prints a byte as its hexadecimal equivalent */
uint8_t nibble;
nibble = (byte & 0b11110000) >> 4;
transmitByte(nibbleToHexCharacter(nibble));
nibble = byte & 0b00001111;
transmitByte(nibbleToHexCharacter(nibble));
}
uint8_t getNumber(void) {
// Gets a numerical 0-255 from the serial port.
// Converts from string to number.
char hundreds = '0';
char tens = '0';
char ones = '0';
char thisChar = '0';
do { /* shift over */
hundreds = tens;
tens = ones;
ones = thisChar;
thisChar = receiveByte(); /* get a new character */
transmitByte(thisChar); /* echo */
} while (thisChar != '\r'); /* until type return */
return (100 * (hundreds - '0') + 10 * (tens - '0') + ones - '0');
}