Line data    Source code

       1             : /*
       2             :    This program is free software: you can redistribute it and/or modify
       3             :    it under the terms of the GNU General Public License as published by
       4             :    the Free Software Foundation, either version 3 of the License, or
       5             :    (at your option) any later version.
       6             : 
       7             :    This program is distributed in the hope that it will be useful,
       8             :    but WITHOUT ANY WARRANTY; without even the implied warranty of
       9             :    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      10             :    GNU General Public License for more details.
      11             : 
      12             :    You should have received a copy of the GNU General Public License
      13             :    along with this program.  If not, see <http://www.gnu.org/licenses/>.
      14             :  */
      15             : 
      16             : #include "AP_Beacon_Pozyx.h"
      17             : 
      18             : #if AP_BEACON_POZYX_ENABLED
      19             : 
      20             : #include <AP_HAL/AP_HAL.h>
      21             : #include <ctype.h>
      22             : #include <stdio.h>
      23             : 
      24             : extern const AP_HAL::HAL& hal;
      25             : 
      26             : // return true if sensor is basically healthy (we are receiving data)
      27           0 : bool AP_Beacon_Pozyx::healthy()
      28             : {
      29             :     // healthy if we have parsed a message within the past 300ms
      30           0 :     return ((AP_HAL::millis() - last_update_ms) < AP_BEACON_TIMEOUT_MS);
      31             : }
      32             : 
      33             : // update the state of the sensor
      34           0 : void AP_Beacon_Pozyx::update(void)
      35             : {
      36           0 :     if (uart == nullptr) {
      37           0 :         return;
      38             :     }
      39             : 
      40             :     // read any available characters
      41           0 :     int16_t nbytes = uart->available();
      42           0 :     while (nbytes-- > 0) {
      43           0 :         char c = uart->read();
      44             : 
      45           0 :         switch (parse_state) {
      46             : 
      47           0 :             default:
      48             :             case ParseState_WaitingForHeader:
      49           0 :                 if (c == AP_BEACON_POZYX_HEADER) {
      50           0 :                     parse_state = ParseState_WaitingForMsgId;
      51           0 :                     linebuf_len = 0;
      52             :                 }
      53           0 :                 break;
      54             : 
      55           0 :             case ParseState_WaitingForMsgId:
      56           0 :                 parse_msg_id = c;
      57           0 :                 switch (parse_msg_id) {
      58           0 :                 case AP_BEACON_POZYX_MSGID_BEACON_CONFIG:
      59             :                 case AP_BEACON_POZYX_MSGID_BEACON_DIST:
      60             :                 case AP_BEACON_POZYX_MSGID_POSITION:
      61           0 :                     parse_state = ParseState_WaitingForLen;
      62           0 :                     break;
      63           0 :                 default:
      64             :                     // invalid message id
      65           0 :                     parse_state = ParseState_WaitingForHeader;
      66           0 :                     break;
      67             :                 }
      68           0 :                 break;
      69             : 
      70           0 :             case ParseState_WaitingForLen:
      71           0 :                 parse_msg_len = c;
      72           0 :                 if (parse_msg_len > AP_BEACON_POZYX_MSG_LEN_MAX) {
      73             :                     // invalid message length
      74           0 :                     parse_state = ParseState_WaitingForHeader;
      75             :                 } else {
      76           0 :                     parse_state = ParseState_WaitingForContents;
      77             :                 }
      78           0 :                 break;
      79             : 
      80           0 :             case ParseState_WaitingForContents:
      81             :                 // add to buffer
      82           0 :                 linebuf[linebuf_len++] = c;
      83           0 :                 if ((linebuf_len == parse_msg_len) || (linebuf_len == sizeof(linebuf))) {
      84             :                     // process buffer
      85           0 :                     parse_buffer();
      86             :                     // reset state for next message
      87           0 :                     parse_state = ParseState_WaitingForHeader;
      88             :                 }
      89           0 :                 break;
      90             :         }
      91             :     }
      92             : }
      93             : 
      94             : // parse buffer
      95           0 : void AP_Beacon_Pozyx::parse_buffer()
      96             : {
      97             :     // check crc
      98           0 :     uint8_t checksum = 0;
      99           0 :     checksum ^= parse_msg_id;
     100           0 :     checksum ^= parse_msg_len;
     101           0 :     for (uint8_t i=0; i<linebuf_len; i++) {
     102           0 :         checksum ^= linebuf[i];
     103             :     }
     104             :     // return if failed checksum check
     105           0 :     if (checksum != 0) {
     106           0 :         return;
     107             :     }
     108             : 
     109           0 :     bool parsed = false;
     110           0 :     switch (parse_msg_id) {
     111             : 
     112           0 :         case AP_BEACON_POZYX_MSGID_BEACON_CONFIG:
     113             :             {
     114           0 :                 uint8_t beacon_id = linebuf[0];
     115             :                 //uint8_t beacon_count = linebuf[1];
     116           0 :                 int32_t beacon_x = (uint32_t)linebuf[5] << 24 | (uint32_t)linebuf[4] << 16 | (uint32_t)linebuf[3] << 8 | (uint32_t)linebuf[2];
     117           0 :                 int32_t beacon_y = (uint32_t)linebuf[9] << 24 | (uint32_t)linebuf[8] << 16 | (uint32_t)linebuf[7] << 8 | (uint32_t)linebuf[6];
     118           0 :                 int32_t beacon_z = (uint32_t)linebuf[13] << 24 | (uint32_t)linebuf[12] << 16 | (uint32_t)linebuf[11] << 8 | (uint32_t)linebuf[10];
     119           0 :                 Vector3f beacon_pos(beacon_x * 0.001f, beacon_y * 0.001f, -beacon_z * 0.001f);
     120           0 :                 if (beacon_pos.length() <= AP_BEACON_DISTANCE_MAX) {
     121           0 :                     set_beacon_position(beacon_id, beacon_pos);
     122           0 :                     parsed = true;
     123             :                 }
     124             :             }
     125           0 :             break;
     126             : 
     127           0 :         case AP_BEACON_POZYX_MSGID_BEACON_DIST:
     128             :             {
     129           0 :                 uint8_t beacon_id = linebuf[0];
     130           0 :                 uint32_t beacon_distance = (uint32_t)linebuf[4] << 24 | (uint32_t)linebuf[3] << 16 | (uint32_t)linebuf[2] << 8 | (uint32_t)linebuf[1];
     131           0 :                 float beacon_dist = beacon_distance*0.001f;
     132           0 :                 if (beacon_dist <= AP_BEACON_DISTANCE_MAX) {
     133           0 :                     set_beacon_distance(beacon_id, beacon_dist);
     134           0 :                     parsed = true;
     135             :                 }
     136             :             }
     137           0 :             break;
     138             : 
     139           0 :         case AP_BEACON_POZYX_MSGID_POSITION:
     140             :             {
     141           0 :                 int32_t vehicle_x = (uint32_t)linebuf[3] << 24 | (uint32_t)linebuf[2] << 16 | (uint32_t)linebuf[1] << 8 | (uint32_t)linebuf[0];
     142           0 :                 int32_t vehicle_y = (uint32_t)linebuf[7] << 24 | (uint32_t)linebuf[6] << 16 | (uint32_t)linebuf[5] << 8 | (uint32_t)linebuf[4];
     143           0 :                 int32_t vehicle_z = (uint32_t)linebuf[11] << 24 | (uint32_t)linebuf[10] << 16 | (uint32_t)linebuf[9] << 8 | (uint32_t)linebuf[8];
     144           0 :                 int16_t position_error = (uint32_t)linebuf[13] << 8 | (uint32_t)linebuf[12];
     145           0 :                 Vector3f veh_pos(Vector3f(vehicle_x * 0.001f, vehicle_y * 0.001f, -vehicle_z * 0.001f));
     146           0 :                 if (veh_pos.length() <= AP_BEACON_DISTANCE_MAX) {
     147           0 :                     set_vehicle_position(veh_pos, position_error);
     148           0 :                     parsed = true;
     149             :                 }
     150             :             }
     151           0 :             break;
     152             : 
     153           0 :         default:
     154             :             // unrecognised message id
     155           0 :             break;
     156             :     }
     157             : 
     158             :     // record success
     159           0 :     if (parsed) {
     160           0 :         last_update_ms = AP_HAL::millis();
     161             :     }
     162             : }
     163             : 
     164             : #endif  // AP_BEACON_POZYX_ENABLED