test_uart_loopback.c

Go to the documentation of this file.

/****************************************************************************
 *
 *  Copyright (C) 2012-2019 PX4 Development Team. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name PX4 nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ****************************************************************************/

/**
 * @file test_uart_loopback.c
 * Tests the uart outputs.
 *
 * @author Lorenz Meier <lorenz@px4.io>
 */

#include <px4_platform_common/px4_config.h>

#include <sys/types.h>

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>

#include <arch/board/board.h>

#include "tests_main.h"

#include <math.h>
#include <float.h>

int test_uart_loopback(int argc, char *argv[])
{

    int uart5_nread = 0;
    int uart2_nread = 0;
    int uart5_nwrite = 0;
    int uart2_nwrite = 0;

    /* opening stdout */
    int stdout_fd = 1;

    int uart2 = open("/dev/ttyS1", O_RDWR | O_NONBLOCK | O_NOCTTY);

    if (uart2 < 0) {
        printf("ERROR opening UART2, aborting..\n");
        return uart2;
    }

    int uart5 = open("/dev/ttyS2", O_RDWR | O_NONBLOCK | O_NOCTTY);

    if (uart5 < 0) {
        if (uart2 >= 0) {
            close(uart2);
        }

        printf("ERROR opening UART5, aborting..\n");
        return 1;
    }

    uint8_t sample_stdout_fd[] = {'C', 'O', 'U', 'N', 'T', ' ', '#', '\n'};
    uint8_t sample_uart2[] = {'C', 'O', 'U', 'N', 'T', ' ', '#', 0};
    uint8_t sample_uart5[] = {'C', 'O', 'U', 'N', 'T', ' ', '#', 0};

    int i, r;

    for (i = 0; i < 1000; i++) {
//      printf("TEST #%d\n",i);
        write(stdout_fd, sample_stdout_fd, sizeof(sample_stdout_fd));

        /* uart2 -> uart5 */
        r = write(uart2, sample_uart2, sizeof(sample_uart2));

        if (r > 0) {
            uart2_nwrite += r;
        }

//      printf("TEST #%d\n",i);
        write(stdout_fd, sample_stdout_fd, sizeof(sample_stdout_fd));

        /* uart2 -> uart5 */
        r = write(uart5, sample_uart5, sizeof(sample_uart5));

        if (r > 0) {
            uart5_nwrite += r;
        }

//      printf("TEST #%d\n",i);
        write(stdout_fd, sample_stdout_fd, sizeof(sample_stdout_fd));

        /* try to read back values */
        do {
            r = read(uart5, sample_uart2, sizeof(sample_uart2));

            if (r > 0) {
                uart5_nread += r;
            }
        } while (r > 0);

//      printf("TEST #%d\n",i);
        write(stdout_fd, sample_stdout_fd, sizeof(sample_stdout_fd));

        do {
            r = read(uart2, sample_uart5, sizeof(sample_uart5));

            if (r > 0) {
                uart2_nread += r;
            }
        } while (r > 0);

//      printf("TEST #%d\n",i);
//      write(stdout_fd, sample_stdout_fd, sizeof(sample_uart5));
    }

    for (i = 0; i < 200000; i++) {

        /* try to read back values */
        r = read(uart5, sample_uart2, sizeof(sample_uart2));

        if (r > 0) {
            uart5_nread += r;
        }

        r = read(uart2, sample_uart5, sizeof(sample_uart5));

        if (r > 0) {
            uart2_nread += r;
        }

        if ((uart2_nread == uart2_nwrite) && (uart5_nread == uart5_nwrite)) {
            break;
        }
    }


    close(stdout_fd);
    close(uart2);
    close(uart5);

    printf("uart2_nwrite %d\n", uart2_nwrite);
    printf("uart5_nwrite %d\n", uart5_nwrite);
    printf("uart2_nread  %d\n", uart2_nread);
    printf("uart5_nread  %d\n", uart5_nread);


    return 0;
}