Skip to main content

SAM4S2A stdio


ASF Wizard​

  • Standard serial I/O (stdio) (driver): Common standard serial I/O management driver that implements a stdio serial interface on SAM devices.
  • USART - Serial interface (service): Common API which abstracts the user from directly accessing the register and provides a generic serial interface using USART.
  • PIO - Parallel Input/Output Controller (driver): The Parallel Input/Output Controller manages up to 32 fully programmable input/output lines. Each I/O line may be dedicated as a general-purpose I/O or be assigned to a function of an embedded peripheral. This assures effective optimization of the pins of a product.

src\config\conf_board.h​

#ifndef CONF_BOARD_H
#define CONF_BOARD_H

#define CONSOLE_UART (Usart *)USART0

/** Enable Com Port. */
#define CONF_BOARD_UART_CONSOLE

#endif    // CONF_BOARD_H

src\config\conf_uart_serial.h​

#ifndef CONF_USART_SERIAL_H
#define CONF_USART_SERIAL_H

/* A reference setting for USART */
/** USART Interface */
#define CONF_UART CONSOLE_UART
/** Baudrate setting */
#define CONF_UART_BAUDRATE 115200
/** Character length setting */
#define CONF_UART_CHAR_LENGTH US_MR_CHRL_8_BIT
/** Parity setting */
#define CONF_UART_PARITY US_MR_PAR_NO
/** Stop bits setting */
#define CONF_UART_STOP_BITS US_MR_NBSTOP_1_BIT

#define USART_SERIAL             CONF_UART
#define USART_SERIAL_ID          ID_USART0
#define USART_SERIAL_BAUDRATE    CONF_UART_BAUDRATE
#define USART_SERIAL_CHAR_LENGTH CONF_UART_CHAR_LENGTH
#define USART_SERIAL_PARITY      CONF_UART_PARITY
#define USART_SERIAL_STOP_BIT    CONF_UART_STOP_BITS

#define PINS_USART0_PIO  PIOA
#define PINS_USART0_ID   USART_SERIAL_ID
#define PINS_USART0_TYPE PIO_PERIPH_A
#define PINS_USART0_ATTR PIO_DEFAULT
#define PINS_USART0_MASK (PIO_PA5A_RXD0 | PIO_PA6A_TXD0)

#endif /* CONF_USART_SERIAL_H_INCLUDED */

Examples​

#include "conf_uart_serial.h"

#include <asf.h>

void serial_init(void) {
    pio_configure(
        PINS_USART0_PIO, PINS_USART0_TYPE, PINS_USART0_MASK, PINS_USART0_ATTR);
    pmc_enable_periph_clk(USART_SERIAL_ID);
    sysclk_enable_peripheral_clock(USART_SERIAL_ID);

    const usart_serial_options_t usart_serial_options
        = {.baudrate   = USART_SERIAL_BAUDRATE,
           .charlength = USART_SERIAL_CHAR_LENGTH,
           .paritytype = USART_SERIAL_PARITY,
           .stopbits   = USART_SERIAL_STOP_BIT};

    stdio_serial_init(USART_SERIAL, &usart_serial_options);
}

int main(void) {
    sysclk_init();
    board_init();
    /* Insert application code here, after the board has been initialized. */
    wdt_disable(WDT);

    serial_init();

    for(;;) {
        uint16_t temp;
        scanf("%d", &temp);
        printf("%d\r\n", temp);
    }
}