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| /**************************************************************************** |
| UART INITIALIZATION |
| |
| This Program enables you to send data from the ATmega32 serial port to |
| the PC so that the data can be read on hyperterminal. This is very |
| useful for debugging purposes when the development system has no |
| display of its own. |
| |
| To send data through the UART printf() is used. |
| |
| uart.c and uart.h must be included in the main project, and the function |
| uart_init() called to enable serial port output. |
| |
| In order to print floating point values, you will need to add the line |
| "-Wl,-u,vfprintf -lprintf_flt -lm" to AVR Studio4 linker options by going to |
| Project->Configuration Options->Custom Options |
| |
| Read the "Detailed Description" section of |
| http://www.nongnu.org/avr-libc/user-manual/group__avr__stdio.html for |
| more detail. |
| |
| *******************************************************************************/ |
| #include <avr/io.h> |
| #include <avr/interrupt.h> |
| #include <stdio.h> |
| #include "uart.h" |
| |
| int put_uart_char(char c, FILE *fd) |
| { |
| while (!(UCSRA & _BV(UDRE))); //Wait for transmit buffer to become empty. |
| UDR = c; //Write the character to the UART. |
| return 0; |
| } |
| |
| void uart_init(void) |
| { |
| //UART Init |
| |
| UCSRB |= (1<<TXEN); // UART TX einschalten |
| UCSRC = (1<<URSEL)|(1<<UCSZ1)|(1<<UCSZ0); // Asynchron 8N1 |
| |
| UBRRH = UBRR_VAL >> 8; |
| UBRRL = UBRR_VAL & 0xFF; |
| |
| |
| |
| //Call fdevopen. This is what binds printf to put_uart_char. The first |
| //parameter is the address of our function that will output a single |
| //character, the second parameter is an optional parameter that is |
| //used for get functions, ie. receiving a character from the UART. |
| //This is the function that uses malloc. |
| |
| fdevopen(&put_uart_char, NULL); |
| |
| //Enable the interrupts globally. |
| |
| SREG |= _BV(SREG_I); |
| } |
| |
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