hott_telemetry.cpp

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/****************************************************************************
 *
 *   Copyright (c) 2012, 2013 PX4 Development Team. All rights reserved.
 *   Author: Simon Wilks <sjwilks@gmail.com>
 *
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 * modification, are permitted provided that the following conditions
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 * 1. Redistributions of source code must retain the above copyright
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 *    used to endorse or promote products derived from this software
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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/**
 * @file hott_telemetry_main.c
 * @author Simon Wilks <sjwilks@gmail.com>
 *
 * Graupner HoTT Telemetry implementation.
 *
 * The HoTT receiver polls each device at a regular interval at which point
 * a data packet can be returned if necessary.
 *
 */

#include <fcntl.h>
#include <px4_platform_common/px4_config.h>
#include <px4_platform_common/defines.h>
#include <px4_platform_common/tasks.h>
#include <poll.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include <systemlib/err.h>
#include <perf/perf_counter.h>

#include "../comms.h"
#include "../messages.h"

#define DEFAULT_UART "/dev/ttyS6";      /**< Serial4 */

static int thread_should_exit = false;      /**< Deamon exit flag */
static int thread_running = false;      /**< Deamon status flag */
static int deamon_task;             /**< Handle of deamon task / thread */
static const char daemon_name[] = "hott_telemetry";
static const char commandline_usage[] =
    "usage: hott_telemetry start|status|stop [-d <device>] [-t <timeout ms>] [-r <read delay us>] [-w <write delay us>]";

static uint8_t read_log[16];

static int timeout_ms = POLL_TIMEOUT_IN_MSECS;
static int read_delay_us = POST_READ_DELAY_IN_USECS;
static int write_delay_us = POST_WRITE_DELAY_IN_USECS;

perf_counter_t  reqs_count;
perf_counter_t  connect_count;
perf_counter_t  recon_port;
perf_counter_t  bin_reply;
perf_counter_t  txt_reply;
perf_counter_t  bad_reply;
perf_counter_t  dead_reply;

/**
 * Deamon management function.
 */
extern "C" __EXPORT int hott_telemetry_main(int argc, char *argv[]);

/**
 * Mainloop of daemon.
 */
int hott_telemetry_thread_main(int argc, char *argv[]);

static int recv_req_id(int uart, uint8_t *id);
static int send_data(int uart, uint8_t *buffer, size_t size);

int
recv_req_id(int uart, uint8_t *id)
{
    uint8_t mode;

    struct pollfd fds;
    fds.fd = uart;
    fds.events = POLLIN;

    if (poll(&fds, 1, timeout_ms) > 0) {
        /* Get the mode: binary or text  */
        read(uart, &mode, sizeof(mode));

        perf_count(reqs_count);

        // Debug log
        for (int x = 15; x > 0; x--) {
            read_log[x] = read_log[x - 1];
        }

        read_log[0] = mode;

        /* if we have a binary mode request */
        if (mode != BINARY_MODE_REQUEST_ID) {
            return PX4_ERROR;
        }

        /* Read the device ID being polled */
        read(uart, id, sizeof(*id));

    } else {
        warnx("UART timeout on TX/RX port");
        return PX4_ERROR;
    }

    return PX4_OK;
}

int
send_data(int uart, uint8_t *buffer, size_t size)
{
    usleep(read_delay_us);

    uint16_t checksum = 0;

    for (size_t i = 0; i < size; i++) {
        if (i == size - 1) {
            /* Set the checksum: the first uint8_t is taken as the checksum. */
            buffer[i] = checksum & 0xff;

        } else {
            checksum += buffer[i];
        }

        write(uart, &buffer[i], sizeof(buffer[i]));

        /* Sleep before sending the next byte. */
        usleep(write_delay_us);
    }

    /* A hack the reads out what was written so the next read from the receiver doesn't get it. */
    /* TODO: Fix this!! */
    uint8_t dummy[size];
    read(uart, &dummy, size);

    return PX4_OK;
}

int
hott_telemetry_thread_main(int argc, char *argv[])
{
    connect_count = perf_alloc(PC_COUNT,    "reconnects       ");
    recon_port = perf_alloc(PC_COUNT,       "reopen port      ");
    reqs_count = perf_alloc(PC_COUNT,       "requests        ");
    bin_reply = perf_alloc(PC_COUNT,        "bin replies     ");
    txt_reply = perf_alloc(PC_COUNT,        "text replies    ");
    bad_reply = perf_alloc(PC_COUNT,        "unknown replies ");
    dead_reply = perf_alloc(PC_COUNT,       "dead replies    ");

    thread_running = true;

    const char *device = DEFAULT_UART;

    /* read commandline arguments */
    for (int i = 0; i < argc && argv[i]; i++) {
        if (strcmp(argv[i], "-d") == 0 || strcmp(argv[i], "--device") == 0) { //device set
            if (argc > i + 1) {
                device = argv[i + 1];

            } else {
                thread_running = false;
                errx(1, "missing parameter to -d\n%s", commandline_usage);
            }
        }
    }

    /* enable UART, writes potentially an empty buffer, but multiplexing is disabled */
    int uart = open_uart(device);

    if (uart < 0) {
        errx(1, "Failed opening HoTT UART, exiting.");
        thread_running = false;
    }

    init_sub_messages();

    uint8_t buffer[MAX_MESSAGE_BUFFER_SIZE];
    size_t size = 0;
    uint8_t id = 0;

    bool connected = true;
    int recon = 0;

    while (!thread_should_exit) {
        // Listen for and serve poll from the receiver.
        if (recv_req_id(uart, &id) == PX4_OK) {
            if (!connected) {
                connected = true;
            }

            switch (id) {
            case EAM_SENSOR_ID:
                build_eam_response(buffer, &size);
                perf_count(bin_reply);
                break;

            case GAM_SENSOR_ID:
                build_gam_response(buffer, &size);
                perf_count(bin_reply);
                break;

            case GPS_SENSOR_ID:
                build_gps_response(buffer, &size);
                perf_count(bin_reply);
                break;

            case BINARY_MODE_REQUEST_ID:
                perf_count(dead_reply);
                break;

            default:
                perf_count(bad_reply);
                continue;   // Not a module we support.
            }

            send_data(uart, buffer, size);

        } else {
            if (connected) {
                connected = false;

            } else {
                recon++;
            }

            if (recon > 100) {
                perf_count(recon_port);
                close(uart);
                uart = open_uart(device);
                perf_reset(reqs_count);
                perf_reset(bin_reply);
                perf_reset(txt_reply);
                perf_reset(dead_reply);
                perf_reset(bad_reply);
            }
        }
    }

    warnx("exiting");

    close(uart);

    thread_running = false;

    perf_free(connect_count);
    perf_free(recon_port);
    perf_free(reqs_count);
    perf_free(bin_reply);
    perf_free(txt_reply);
    perf_free(bad_reply);
    perf_free(dead_reply);

    return 0;
}

/**
 * Process command line arguments and start the daemon.
 */
int
hott_telemetry_main(int argc, char *argv[])
{
    if (argc < 2) {
        errx(1, "missing command\n%s", commandline_usage);
    }

    /* read commandline arguments */
    for (int i = 0; i < argc && argv[i]; i++) {
        if (strcmp(argv[i], "-t") == 0 || strcmp(argv[i], "--timeout") == 0) { //device set
            if (argc > i + 1) {
                timeout_ms = atoi(argv[i + 1]);

            } else {
                errx(1, "missing parameter to -t\n%s", commandline_usage);
            }
        }

        if (strcmp(argv[i], "-r") == 0 || strcmp(argv[i], "--read-delay") == 0) { //device set
            if (argc > i + 1) {
                read_delay_us = atoi(argv[i + 1]);

            } else {
                errx(1, "missing parameter to -r\n%s", commandline_usage);
            }
        }

        if (strcmp(argv[i], "-w") == 0 || strcmp(argv[i], "--write-delay") == 0) { //device set
            if (argc > i + 1) {
                write_delay_us = atoi(argv[i + 1]);

            } else {
                errx(1, "missing parameter to -w\n%s", commandline_usage);
            }
        }
    }

    if (!strcmp(argv[1], "start")) {

        if (thread_running) {
            warnx("already running");
            exit(0);
        }

        thread_should_exit = false;
        deamon_task = px4_task_spawn_cmd(daemon_name,
                         SCHED_DEFAULT,
                         SCHED_PRIORITY_DEFAULT,
                         1500,
                         hott_telemetry_thread_main,
                         (argv) ? (char *const *)&argv[2] : (char *const *)NULL);
        exit(0);
    }

    if (!strcmp(argv[1], "stop")) {
        thread_should_exit = true;
        exit(0);
    }

    if (!strcmp(argv[1], "status")) {
        if (thread_running) {
            warnx("is running");


            for (int x = 15; x >= 0; x--) {
                printf("%2x ", read_log[x]);
            }

            printf("\npoll timeout     : %i ms\n", timeout_ms);
            printf("post write delay : %i us\n", write_delay_us);
            printf("post read delay  : %i us\n", read_delay_us);
            perf_print_counter(recon_port);
            perf_print_counter(connect_count);
            perf_print_counter(reqs_count);
            perf_print_counter(bin_reply);
            perf_print_counter(txt_reply);
            perf_print_counter(bad_reply);
            perf_print_counter(dead_reply);

        } else {
            warnx("not started");
        }

        exit(0);
    }

    errx(1, "unrecognized command\n%s", commandline_usage);
}