px_uart_stdio.h : UART stdio redirect module

Description

Initialises the stdout stream to output to UART.

File(s):

• arch/avr/inc/px_uart_stdio.h
• arch/avr/src/px_uart_stdio.c

This component initialises the stdout stream to output over UART.

px_uart_stdio_putchar() will intercept all line feed characters (\n) and replace it with a carriage return, line feed sequence (\r\n).

References:

1. newlib-2.5.0/newlib/libc/sys/arm/syscalls.c

Example:

#include <stdio.h>
 
#include "px_board.h"
#include "px_uart.h"
#include "px_uart_stdio.h"
 
// Create UART handle object
px_uart_handle_t px_uart_handle;
 
int main(void)
{
    uint8_t counter;
 
    // Initialise board
    px_board_init();
    // Initialise module
    px_uart_init();
 
    // Open UART0 @ 115200 BAUD, 8 data bits, no parity, 1 stop bit
    px_uart_open2(&px_uart_handle,
                  PX_UART_NR_0,
                  115200, 
                  PX_UART_DATA_BITS_8, 
                  PX_UART_PARITY_NONE, 
                  PX_UART_STOP_BITS_1);
    // Initialise stdio stream to use the specified UART
    px_uart_stdio_init(&px_uart_handle);
 
    // Enable interrupts
    px_interrupts_enable();
 
    printf("Starting counter...\n");
    for(counter = 0; counter < 8; counter++)
    {
        printf("Counter = %u\n", counter);
    }
}

Functions
void	px_uart_stdio_init (px_uart_handle_t *handle)
	Initialise stdout stream to use a UART driver. More...
int	px_uart_stdio_putchar (char data, FILE *stream)
	Function to send a byte. More...
int	px_uart_stdio_getchar (FILE *stream)
	Function to receive a byte. More...

Function Documentation

px_uart_stdio_init()

void px_uart_stdio_init

(

px_uart_handle_t *

handle

)

Initialise stdout stream to use a UART driver.

px_uart_stdio_putchar() is provided as the handler for all outgoing data. A px_uart_stdout_stream structure is declared statically so that heap memory is not used (no malloc).

Parameters

handle

opened handle to UART peripheral

Initialise stdout stream to use a UART driver.

px_uart_stdio_putchar() is provided as the handler for all outgoing data.

Parameters

handle

opened handle to UART peripheral

Definition at line 94 of file px_uart_stdio.c.

px_uart_stdio_putchar()

int px_uart_stdio_putchar	(	char	data,
		FILE *	stream
	)

Function to send a byte.

Every carriage return ("\n") will be intercepted and replaced with a carriage return, new line sequence ("\r\n").

Parameters

data	byte to send
stream	stream to output data to (not used)

Returns

int always returns 0

Definition at line 54 of file px_uart_stdio.c.

px_uart_stdio_getchar()

int px_uart_stdio_getchar

(

FILE *

stream

)

Function to receive a byte.

This function will block until a character has been received.

Parameters

stream

stream to output data to (not used)

Returns

int received byte

Definition at line 69 of file px_uart_stdio.c.