messages.cpp

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/****************************************************************************
 *
 *   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
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/**
 * @file messages.c
 *
 */

#include "messages.h"

#include <math.h>
#include <stdio.h>
#include <string.h>
#include <lib/ecl/geo/geo.h>
#include <unistd.h>
#include <px4_platform_common/defines.h>
#include <uORB/topics/airspeed.h>
#include <uORB/topics/battery_status.h>
#include <uORB/topics/esc_status.h>
#include <uORB/topics/home_position.h>
#include <uORB/topics/vehicle_air_data.h>
#include <uORB/topics/vehicle_gps_position.h>

#include <drivers/drv_hrt.h>

/* The board is very roughly 5 deg warmer than the surrounding air */
#define BOARD_TEMP_OFFSET_DEG 5

static int _battery_sub = -1;
static int _gps_sub = -1;
static int _home_sub = -1;
static int _airdata_sub = -1;
static int _airspeed_sub = -1;
static int _esc_sub = -1;

static orb_advert_t _esc_pub = nullptr;

static bool _home_position_set = false;
static double _home_lat = 0.0d;
static double _home_lon = 0.0d;

void
init_sub_messages(void)
{
    _battery_sub = orb_subscribe(ORB_ID(battery_status));
    _gps_sub = orb_subscribe(ORB_ID(vehicle_gps_position));
    _home_sub = orb_subscribe(ORB_ID(home_position));
    _airdata_sub = orb_subscribe(ORB_ID(vehicle_air_data));
    _airspeed_sub = orb_subscribe(ORB_ID(airspeed));
    _esc_sub = orb_subscribe(ORB_ID(esc_status));
}

void
init_pub_messages(void)
{
}

void
build_gam_request(uint8_t *buffer, size_t *size)
{
    struct gam_module_poll_msg msg;
    *size = sizeof(msg);
    memset(&msg, 0, *size);

    msg.mode = BINARY_MODE_REQUEST_ID;
    msg.id = GAM_SENSOR_ID;

    memcpy(buffer, &msg, *size);
}

void
publish_gam_message(const uint8_t *buffer)
{
    struct gam_module_msg msg;
    size_t size = sizeof(msg);
    memset(&msg, 0, size);
    memcpy(&msg, buffer, size);
    struct esc_status_s esc;
    memset(&esc, 0, sizeof(esc));

    // Publish it.
    esc.timestamp = hrt_absolute_time();
    esc.esc_count = 1;
    esc.esc_connectiontype = esc_status_s::ESC_CONNECTION_TYPE_PPM;

    esc.esc[0].esc_rpm = (uint16_t)((msg.rpm_H << 8) | (msg.rpm_L & 0xff)) * 10;
    esc.esc[0].esc_temperature = msg.temperature1 - 20;
    esc.esc[0].esc_voltage = static_cast<float>((msg.main_voltage_H << 8) | (msg.main_voltage_L & 0xff)) * 0.1F;
    esc.esc[0].esc_current = static_cast<float>((msg.current_H << 8) | (msg.current_L & 0xff)) * 0.1F;

    /* announce the esc if needed, just publish else */
    if (_esc_pub != nullptr) {
        orb_publish(ORB_ID(esc_status), _esc_pub, &esc);

    } else {
        _esc_pub = orb_advertise(ORB_ID(esc_status), &esc);
    }
}

void
build_eam_response(uint8_t *buffer, size_t *size)
{
    /* get a local copy of the current sensor values */
    vehicle_air_data_s airdata = {};
    orb_copy(ORB_ID(vehicle_air_data), _airdata_sub, &airdata);

    /* get a local copy of the battery data */
    struct battery_status_s battery;
    memset(&battery, 0, sizeof(battery));
    orb_copy(ORB_ID(battery_status), _battery_sub, &battery);

    struct eam_module_msg msg;
    *size = sizeof(msg);
    memset(&msg, 0, *size);

    msg.start = START_BYTE;
    msg.eam_sensor_id = EAM_SENSOR_ID;
    msg.sensor_text_id = EAM_SENSOR_TEXT_ID;

    msg.temperature1 = (uint8_t)(airdata.baro_temp_celcius + 20);
    msg.temperature2 = msg.temperature1 - BOARD_TEMP_OFFSET_DEG;

    msg.main_voltage_L = (uint8_t)(battery.voltage_v * 10);

    uint16_t alt = (uint16_t)(airdata.baro_alt_meter + 500);
    msg.altitude_L = (uint8_t)alt & 0xff;
    msg.altitude_H = (uint8_t)(alt >> 8) & 0xff;

    /* get a local copy of the airspeed data */
    struct airspeed_s airspeed;
    memset(&airspeed, 0, sizeof(airspeed));
    orb_copy(ORB_ID(airspeed), _airspeed_sub, &airspeed);

    uint16_t speed = (uint16_t)(airspeed.indicated_airspeed_m_s * 3.6f);
    msg.speed_L = (uint8_t)speed & 0xff;
    msg.speed_H = (uint8_t)(speed >> 8) & 0xff;

    msg.stop = STOP_BYTE;
    memcpy(buffer, &msg, *size);
}

void
build_gam_response(uint8_t *buffer, size_t *size)
{
    /* get a local copy of the ESC Status values */
    struct esc_status_s esc;
    memset(&esc, 0, sizeof(esc));
    orb_copy(ORB_ID(esc_status), _esc_sub, &esc);

    struct gam_module_msg msg;
    *size = sizeof(msg);
    memset(&msg, 0, *size);

    msg.start = START_BYTE;
    msg.gam_sensor_id = GAM_SENSOR_ID;
    msg.sensor_text_id = GAM_SENSOR_TEXT_ID;

    msg.temperature1 = esc.esc[0].esc_temperature + 20;
    msg.temperature2 = 20;  // 0 deg. C.

    const uint16_t voltage = (uint16_t)(esc.esc[0].esc_voltage * 10.0F);
    msg.main_voltage_L = (uint8_t)voltage & 0xff;
    msg.main_voltage_H = (uint8_t)(voltage >> 8) & 0xff;

    const uint16_t current = (uint16_t)(esc.esc[0].esc_current * 10.0F);
    msg.current_L = (uint8_t)current & 0xff;
    msg.current_H = (uint8_t)(current >> 8) & 0xff;

    const uint16_t rpm = (uint16_t)(esc.esc[0].esc_rpm * 0.1f);
    msg.rpm_L = (uint8_t)rpm & 0xff;
    msg.rpm_H = (uint8_t)(rpm >> 8) & 0xff;

    msg.stop = STOP_BYTE;
    memcpy(buffer, &msg, *size);
}

void
build_gps_response(uint8_t *buffer, size_t *size)
{
    /* get a local copy of the battery data */
    struct vehicle_gps_position_s gps;
    memset(&gps, 0, sizeof(gps));
    orb_copy(ORB_ID(vehicle_gps_position), _gps_sub, &gps);

    struct gps_module_msg msg;
    *size = sizeof(msg);
    memset(&msg, 0, *size);

    msg.start = START_BYTE;
    msg.sensor_id = GPS_SENSOR_ID;
    msg.sensor_text_id = GPS_SENSOR_TEXT_ID;

    msg.gps_num_sat = gps.satellites_used;

    /* The GPS fix type: 0 = none, 2 = 2D, 3 = 3D */
    msg.gps_fix_char = (uint8_t)(gps.fix_type + 48);
    msg.gps_fix = (uint8_t)(gps.fix_type + 48);

    /* No point collecting more data if we don't have a 3D fix yet */
    if (gps.fix_type > 2) {
        /* Current flight direction */
        msg.flight_direction = (uint8_t)(gps.cog_rad * M_RAD_TO_DEG_F);

        /* GPS speed */
        uint16_t speed = (uint16_t)(gps.vel_m_s * 3.6f);
        msg.gps_speed_L = (uint8_t)speed & 0xff;
        msg.gps_speed_H = (uint8_t)(speed >> 8) & 0xff;

        /* Get latitude in degrees, minutes and seconds */
        double lat = ((double)(gps.lat)) * 1e-7d;

        /* Set the N or S specifier */
        msg.latitude_ns = 0;

        if (lat < 0) {
            msg.latitude_ns = 1;
            lat = abs(lat);
        }

        int deg;
        int min;
        int sec;
        convert_to_degrees_minutes_seconds(lat, &deg, &min, &sec);

        uint16_t lat_min = (uint16_t)(deg * 100 + min);
        msg.latitude_min_L = (uint8_t)lat_min & 0xff;
        msg.latitude_min_H = (uint8_t)(lat_min >> 8) & 0xff;
        uint16_t lat_sec = (uint16_t)(sec);
        msg.latitude_sec_L = (uint8_t)lat_sec & 0xff;
        msg.latitude_sec_H = (uint8_t)(lat_sec >> 8) & 0xff;

        /* Get longitude in degrees, minutes and seconds */
        double lon = ((double)(gps.lon)) * 1e-7d;

        /* Set the E or W specifier */
        msg.longitude_ew = 0;

        if (lon < 0) {
            msg.longitude_ew = 1;
            lon = abs(lon);
        }

        convert_to_degrees_minutes_seconds(lon, &deg, &min, &sec);

        uint16_t lon_min = (uint16_t)(deg * 100 + min);
        msg.longitude_min_L = (uint8_t)lon_min & 0xff;
        msg.longitude_min_H = (uint8_t)(lon_min >> 8) & 0xff;
        uint16_t lon_sec = (uint16_t)(sec);
        msg.longitude_sec_L = (uint8_t)lon_sec & 0xff;
        msg.longitude_sec_H = (uint8_t)(lon_sec >> 8) & 0xff;

        /* Altitude */
        uint16_t alt = (uint16_t)(gps.alt * 1e-3f + 500.0f);
        msg.altitude_L = (uint8_t)alt & 0xff;
        msg.altitude_H = (uint8_t)(alt >> 8) & 0xff;

        /* Get any (and probably only ever one) _home_sub position report */
        bool updated;
        orb_check(_home_sub, &updated);

        if (updated) {
            /* get a local copy of the home position data */
            struct home_position_s home;
            memset(&home, 0, sizeof(home));
            orb_copy(ORB_ID(home_position), _home_sub, &home);

            _home_lat = home.lat;
            _home_lon = home.lon;
            _home_position_set = true;
        }

        /* Distance from home */
        if (_home_position_set) {
            uint16_t dist = (uint16_t)get_distance_to_next_waypoint(_home_lat, _home_lon, lat, lon);

            msg.distance_L = (uint8_t)dist & 0xff;
            msg.distance_H = (uint8_t)(dist >> 8) & 0xff;

            /* Direction back to home */
            uint16_t bearing = (uint16_t)(get_bearing_to_next_waypoint(_home_lat, _home_lon, lat, lon) * M_RAD_TO_DEG_F);
            msg.home_direction = (uint8_t)bearing >> 1;
        }
    }

    msg.stop = STOP_BYTE;
    memcpy(buffer, &msg, *size);
}

void
convert_to_degrees_minutes_seconds(double val, int *deg, int *min, int *sec)
{
    *deg = (int)val;

    double delta = val - *deg;
    const double min_d = delta * 60.0d;
    *min = (int)min_d;
    delta = min_d - *min;
    *sec = (int)(delta * 10000.0d);
}