text: /****************************************************************************
   *
   *   Copyright (C) 2012 PX4 Development Team. All rights reserved.
   *   Author: @author Simon Wilks <sjwilks@gmail.com>
   *
   * 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_hott_telemetry.c
   *
   * Tests the Graupner HoTT telemetry support.
   *
   */
  
  /****************************************************************************
   * Included Files
   ****************************************************************************/
  
  #include <drivers/drv_gpio.h>
  #include <px4_config.h>
  #include <px4_defines.h>
  #include <px4_log.h>
  #include <sys/types.h>
  #include <systemlib/err.h>
  
  #include <errno.h>
  #include <fcntl.h>
  #include <poll.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <termios.h>
  #include <unistd.h>
  
  #include "tests.h"
  
  
  /****************************************************************************
   * Pre-processor Definitions
   ****************************************************************************/
  
  /****************************************************************************
   * Private Types
   ****************************************************************************/
  
  /****************************************************************************
   * Private Function Prototypes
   ****************************************************************************/
  
  /****************************************************************************
   * Private Data
   ****************************************************************************/
  
  /****************************************************************************
   * Public Data
   ****************************************************************************/
  
  /****************************************************************************
   * Private Functions
   ****************************************************************************/
  static int open_uart(const char *device)
  {
  	/* baud rate */
  	int speed = B19200;
  
  	/* open uart */
  	int uart = open(device, O_RDWR | O_NOCTTY);
  
  	if (uart < 0) {
  		PX4_ERR("FAIL: Error opening port");
  		return ERROR;
  	}
  
  	/* Try to set baud rate */
  	struct termios uart_config;
  
  	/* Fill the struct for the new configuration */
  	tcgetattr(uart, &uart_config);
  
  	/* Clear ONLCR flag (which appends a CR for every LF) */
  	uart_config.c_oflag &= ~ONLCR;
  
  	/* Set baud rate */
  	if (cfsetispeed(&uart_config, speed) < 0 || cfsetospeed(&uart_config, speed) < 0) {
  		PX4_ERR("FAIL: Error setting baudrate / termios config for cfsetispeed, cfsetospeed");
  		return ERROR;
  	}
  
  	if (tcsetattr(uart, TCSANOW, &uart_config) < 0) {
  		PX4_ERR("FAIL: Error setting baudrate / termios config for tcsetattr");
  		return ERROR;
  	}
  
  	return uart;
  }
  
  /****************************************************************************
   * Public Functions
   ****************************************************************************/
  
  /****************************************************************************
   * Name: test_hott_telemetry
   ****************************************************************************/
  
  int test_hott_telemetry(int argc, char *argv[])
  {
  	PX4_INFO("HoTT Telemetry Test Requirements:");
  	PX4_INFO("- Radio on and Electric Air. Mod on (telemetry -> sensor select).");
  	PX4_INFO("- Receiver telemetry port must be in telemetry mode.");
  	PX4_INFO("- Connect telemetry wire to /dev/ttyS1 (USART2).");
  	PX4_INFO("Testing...");
  
  	const char device[] = "/dev/ttyS1";
  	int fd = open_uart(device);
  
  	if (fd < 0) {
  		close(fd);
  		return ERROR;
  	}
  
  #ifdef TIOCSSINGLEWIRE
  	/* Activate single wire mode */
  	ioctl(fd, TIOCSSINGLEWIRE, SER_SINGLEWIRE_ENABLED);
  #endif
  
  	char send = 'a';
  	write(fd, &send, 1);
  
  	/* Since TX and RX are now connected we should be able to read in what we wrote */
  	const int timeout = 1000;
  	struct pollfd fds[] = { { .fd = fd, .events = POLLIN } };
  
  	if (poll(fds, 1, timeout) == 0) {
  		PX4_ERR("FAIL: Could not read sent data.");
  		return 1;
  	}
  
  	char receive;
  	read(fd, &receive, 1);
  	PX4_INFO("PASS: Single wire enabled. Sent %x and received %x", send, receive);
  
  
  	/* Attempt to read HoTT poll messages from the HoTT receiver */
  	int received_count = 0;
  	int valid_count = 0;
  	const int max_polls = 5;
  	uint8_t byte;
  
  	for (; received_count < 5; received_count++) {
  		if (poll(fds, 1, timeout) == 0) {
  			PX4_ERR("FAIL: Could not read sent data. Is your HoTT receiver plugged in on %s?", device);
  			return 1;
  
  		} else {
  			read(fd, &byte, 1);
  
  			if (byte == 0x80) {
  				valid_count++;
  			}
  
  			/* Read the device ID being polled */
  			read(fd, &byte, 1);
  		}
  	}
  
  	if (received_count > 0 && valid_count > 0) {
  		if (received_count == max_polls && valid_count == max_polls) {
  			PX4_INFO("PASS: Received %d out of %d valid byte pairs from the HoTT receiver device.", received_count, max_polls);
  
  		} else {
  			PX4_WARN("WARN: Received %d out of %d byte pairs of which %d were valid from the HoTT receiver device.", received_count,
  				 max_polls, valid_count);
  		}
  
  	} else {
  		/* Let's work out what went wrong */
  		if (received_count == 0) {
  			PX4_ERR("FAIL: Could not read any polls from HoTT receiver device.");
  			return 1;
  		}
  
  		if (valid_count == 0) {
  			PX4_ERR("FAIL: Received unexpected values from the HoTT receiver device.");
  			return 1;
  		}
  	}
  
  
  	/* Attempt to send a HoTT response messages */
  	uint8_t response[] = {0x7c, 0x8e, 0x00, 0xe0, 0x00, 0x80, 0x00, 0x00, 0x00, 0x00, \
  			      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, \
  			      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xf4, 0x01, 0x00, 0x00, \
  			      0x19, 0x00, 0x00, 0x00, 0x30, 0x75, 0x78, 0x00, 0x00, 0x00, \
  			      0x00, 0x00, 0x00, 0x7d, 0x12
  			     };
  
  	usleep(5000);
  
  	for (unsigned int i = 0; i < sizeof(response); i++) {
  		write(fd, &response[i], 1);
  		usleep(1000);
  	}
  
  	PX4_INFO("PASS: Response sent to the HoTT receiver device. Voltage should now show 2.5V.");
  
  
  #ifdef TIOCSSINGLEWIRE
  	/* Disable single wire */
  	ioctl(fd, TIOCSSINGLEWIRE, ~SER_SINGLEWIRE_ENABLED);
  #endif
  
  	write(fd, &send, 1);
  
  	/* We should timeout as there will be nothing to read (TX and RX no longer connected) */
  	if (poll(fds, 1, timeout) == 0) {
  		PX4_ERR("FAIL: timeout expected.");
  		return 1;
  	}
  
  	PX4_INFO("PASS: Single wire disabled.");
  
  	close(fd);
  	return 0;
  }
  