zr-v4/libraries/AP_Proximity/AP_Proximity_NanaRadar_MR72.cpp

/*
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <AP_HAL/AP_HAL.h>
#include "AP_Proximity_NanaRadar_MR72.h"
#include <AP_SerialManager/AP_SerialManager.h>
#include <AP_Math/crc.h>
#include <ctype.h>
#include <stdio.h>
#include <GCS_MAVLink/GCS.h>

extern const AP_HAL::HAL& hal;

/*
   The constructor also initialises the proximity sensor. Note that this
   constructor is not called until detect() returns true, so we
   already know that we should setup the proximity sensor
*/
AP_Proximity_NanaRadar_MR72::AP_Proximity_NanaRadar_MR72(
    AP_Proximity &_frontend,
    AP_Proximity::Proximity_State &_state) :
    AP_Proximity_Backend(_frontend, _state)
{
    const AP_SerialManager &serial_manager = AP::serialmanager();

    uart = serial_manager.find_serial(AP_SerialManager::SerialProtocol_Lidar360, 0);
    if (uart != nullptr) {
        uart->begin(serial_manager.find_baudrate(AP_SerialManager::SerialProtocol_Lidar360, 0));
    }
}

// detect if a TeraRanger Tower proximity sensor is connected by looking for a configured serial port
bool AP_Proximity_NanaRadar_MR72::detect()
{
    AP_HAL::UARTDriver *uart = nullptr;
    uart = AP::serialmanager().find_serial(AP_SerialManager::SerialProtocol_Lidar360, 0);
    return uart != nullptr;
}

// update the state of the sensor
void AP_Proximity_NanaRadar_MR72::update(void)
{
    if (uart == nullptr) {
        return;
    }

    // process incoming messages
    read_sensor_data();

    // check for timeout and set health status
    if ((_last_distance_received_ms == 0) || (AP_HAL::millis() - _last_distance_received_ms > PROXIMITY_TRTOWER_TIMEOUT_MS)) {
        set_status(AP_Proximity::Status::NoData);
    } else {
        set_status(AP_Proximity::Status::Good);
    }
}

// get maximum and minimum distances (in meters) of primary sensor
float AP_Proximity_NanaRadar_MR72::distance_max() const
{
    return 40.0f;
}
float AP_Proximity_NanaRadar_MR72::distance_min() const
{
    return 0.20f;
}

// check for replies from sensor, returns true if at least one message was processed
bool AP_Proximity_NanaRadar_MR72::read_sensor_data()
{
    if (uart == nullptr) {
        return false;
    }

    uint16_t message_count = 0;
    int16_t nbytes = uart->available();
    while (nbytes-- > 0) {
        // uint8_t c = uart->read();
        // gcs().send_text(MAV_SEVERITY_INFO, "getc 0x%02x",c);
        if (uart->read() == Head1)
        { //判断数据包帧头0x54
            buffer[0] = Head1;
            // gcs().send_text(MAV_SEVERITY_INFO, "getc 0x%02x",buffer[0]);
            if (uart->read() == Head2)
            { //判断数据包帧头0X48
                buffer[1] = Head2;
                // gcs().send_text(MAV_SEVERITY_INFO, "getc 0x%02x",buffer[1]);
                for (int i = 2; i < 19; i++)
                { //存储数据到数组
                    buffer[i] = uart->read();
                    // gcs().send_text(MAV_SEVERITY_INFO, "%02d: 0x%02x",i,buffer[i]);
                }
                CheckSum = crc_crc8(buffer,18);
                // gcs().send_text(MAV_SEVERITY_INFO, "crc 0x%02x, rec:0x%02x",CheckSum,buffer[18]);
                if (buffer[18] == CheckSum)
                { //按照协议对收到的数据进行校验
                    update_sector_data(0,   UINT16_VALUE(buffer[2],  buffer[3]));   // d1
                    update_sector_data(45,  UINT16_VALUE(buffer[4], buffer[5]));  // d8
                    update_sector_data(90,  UINT16_VALUE(buffer[6], buffer[7]));  // d7
                    update_sector_data(135, UINT16_VALUE(buffer[8], buffer[9]));  // d6
                    update_sector_data(180, UINT16_VALUE(buffer[10], buffer[11]));  // d5
                    update_sector_data(225, UINT16_VALUE(buffer[12],  buffer[13]));   // d4
                    update_sector_data(270, UINT16_VALUE(buffer[14],  buffer[15]));   // d3
                    update_sector_data(315, UINT16_VALUE(buffer[16],  buffer[17]));   // d2

                    message_count++;
                }
            }
        }

    }
    return (message_count > 0);
}

// process reply
void AP_Proximity_NanaRadar_MR72::update_sector_data(int16_t angle_deg, uint16_t distance_cm)
{
    uint8_t sector;
    if (convert_angle_to_sector(angle_deg, sector)) {
        _angle[sector] = angle_deg;
        _distance[sector] = ((float) distance_cm) / 100;
        _distance_valid[sector] = distance_cm != 0xffff;
        _last_distance_received_ms = AP_HAL::millis();
        // update boundary used for avoidance
        update_boundary_for_sector(sector, true);
    }
}