decawave_anchorless_communication.c

Go to the documentation of this file.

/*
 * Serial_Communication.c
 *
 *  Created on: Jul 25, 2017
 *      Author: Steven van der Helm
 */
 
/*
 * Copyright (C) C. DW
 *
 * This file is part of paparazzi
 *
 * paparazzi 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 2, or (at your option)
 * any later version.
 *
 * paparazzi 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 paparazzi; see the file COPYING.  If not, see
 * <http://www.gnu.org/licenses/>.
 */
#include "decawave_anchorless_communication.h"
#include "subsystems/datalink/telemetry.h"
#include "subsystems/radio_control.h"
#include "state.h"
#include "mcu_periph/uart.h"
#include "subsystems/abi.h"
#include <stdio.h>
 
#define UWB_SERIAL_PORT (&((SERIAL_UART).device))
struct link_device *external_device = UWB_SERIAL_PORT;
 
// Some meta data for serial communication
#define UWB_SERIAL_COMM_MAX_MESSAGE 20
#define UWB_SERIAL_COMM_END_MARKER 255
#define UWB_SERIAL_COMM_SPECIAL_BYTE 253
#define UWB_SERIAL_COMM_START_MARKER 254
#define UWB_SERIAL_COMM_NODE_STATE_SIZE 7
 
#define UWB_SERIAL_COMM_NUM_NODES 3 // How many nodes actually are in the network
#define UWB_SERIAL_COMM_DIST_NUM_NODES UWB_SERIAL_COMM_NUM_NODES-1  // How many distant nodes are in the network (one less than the toal number of nodes)
 
// Serial message
 
#define UWB_SERIAL_COMM_RANGE 0
#define UWB_SERIAL_COMM_VX 1
#define UWB_SERIAL_COMM_VY 2
#define UWB_SERIAL_COMM_Z 3
#define UWB_SERIAL_COMM_AX 4
#define UWB_SERIAL_COMM_AY 5
#define UWB_SERIAL_COMM_YAWR 6
 
struct nodeState {
  uint8_t nodeAddress;
  float r;
  float vx;
  float vy;
  float z;
  float ax;
  float ay;
  float yawr;
  bool state_updated[UWB_SERIAL_COMM_NODE_STATE_SIZE];
};
 
static struct nodeState states[UWB_SERIAL_COMM_DIST_NUM_NODES];
 
static void handleNewStateValue(uint8_t nodeIndex, uint8_t msg_type, float value)
{
  struct nodeState *node = &states[nodeIndex];
  switch (msg_type) {
    case UWB_SERIAL_COMM_RANGE :
      node->r = value;
      node->state_updated[UWB_SERIAL_COMM_RANGE] = true;
      break;
    case UWB_SERIAL_COMM_VX :
      node->vx = value;
      node->state_updated[UWB_SERIAL_COMM_VX] = true;
      break;
    case UWB_SERIAL_COMM_VY :
      node->vy = value;
      node->state_updated[UWB_SERIAL_COMM_VY] = true;
      break;
    case UWB_SERIAL_COMM_Z :
      node->z = value;
      node->state_updated[UWB_SERIAL_COMM_Z] = true;
      break;
    case UWB_SERIAL_COMM_AX :
      node->ax = value;
      node->state_updated[UWB_SERIAL_COMM_AX] = true;
      break;
    case UWB_SERIAL_COMM_AY :
      node->ay = value;
      node->state_updated[UWB_SERIAL_COMM_AY] = true;
      break;
    case UWB_SERIAL_COMM_YAWR :
      node->yawr = value;
      node->state_updated[UWB_SERIAL_COMM_YAWR] = true;
      break;
  }
}
 
static void decodeHighBytes(uint8_t bytes_received, uint8_t *received_message)
{
  static uint8_t receive_buffer[4];
  float tempfloat;
  uint8_t data_received_count = 0;
  uint8_t this_address = received_message[1];
  uint8_t msg_from = received_message[2];
  uint8_t msg_type = received_message[3];
  uint8_t nodeIndex = msg_from - 1 - (uint8_t)(this_address < msg_from);
  for (uint8_t i = 4; i < bytes_received - 1; i++) {
    // Skip the begin marker (0), this address (1), remote address (2), message type (3), and end marker (bytes_received-1)
    uint8_t var_byte = received_message[i];
    if (var_byte == UWB_SERIAL_COMM_SPECIAL_BYTE) {
      i++;
      var_byte = var_byte + received_message[i];
    }
    if (data_received_count <= 4) {
      receive_buffer[data_received_count] = var_byte;
    }
    data_received_count++;
  }
  if (data_received_count == 4) {
    // Move memory from integer buffer to float variable
    memcpy(&tempfloat, &receive_buffer, 4);
    // Set the variable to the appropriate type and store it in state
    handleNewStateValue(nodeIndex, msg_type, tempfloat);
  }
}
 
static void encodeHighBytes(uint8_t *send_data, uint8_t msg_size, uint8_t *data_send_buffer, uint8_t *data_total_send)
{
  uint8_t data_send_count = msg_size;
  *data_total_send = 0;
  for (uint8_t i = 0; i < data_send_count; i++) {
    if (send_data[i] >= UWB_SERIAL_COMM_SPECIAL_BYTE) {
      data_send_buffer[*data_total_send] = UWB_SERIAL_COMM_SPECIAL_BYTE;
      (*data_total_send)++;
      data_send_buffer[*data_total_send] = send_data[i] - UWB_SERIAL_COMM_SPECIAL_BYTE;
    } else {
      data_send_buffer[*data_total_send] = send_data[i];
    }
    (*data_total_send)++;
  }
}
 
static void sendFloat(uint8_t msg_type, float data)
{
  static uint8_t data_send_buffer[UWB_SERIAL_COMM_MAX_MESSAGE];
  static uint8_t data_total_send = 0;
 
  // Make bytes of the float
  uint8_t floatbyte[4];
  memcpy(floatbyte, &data, 4);
  encodeHighBytes(floatbyte, 4, data_send_buffer, &data_total_send);
 
  UWB_SERIAL_PORT->put_byte(UWB_SERIAL_PORT->periph, 0, UWB_SERIAL_COMM_START_MARKER);
  UWB_SERIAL_PORT->put_byte(UWB_SERIAL_PORT->periph, 0, msg_type);
 
  for (uint8_t i = 0; i < data_total_send; i++) {
    UWB_SERIAL_PORT->put_byte(UWB_SERIAL_PORT->periph, 0, data_send_buffer[i]);
  }
 
  UWB_SERIAL_PORT->put_byte(UWB_SERIAL_PORT->periph, 0, UWB_SERIAL_COMM_END_MARKER);
}
 
static void setNodeStatesFalse(uint8_t index)
{
  for (uint8_t j = 0; j < UWB_SERIAL_COMM_NODE_STATE_SIZE; j++) {
    states[index].state_updated[j] = false;
  }
}
 
static void checkStatesUpdated(void)
{
  bool checkbool;
  for (uint8_t i = 0; i < UWB_SERIAL_COMM_DIST_NUM_NODES; i++) {
    checkbool = true;
    for (uint8_t j = 0; j < UWB_SERIAL_COMM_NODE_STATE_SIZE; j++) {
      checkbool = checkbool && states[i].state_updated[j];
    }
    if (checkbool) {
      AbiSendMsgUWB_COMMUNICATION(UWB_COMM_ID, i, states[i].r, states[i].vx, states[i].vy, states[i].z, states[i].ax, states[i].ay, states[i].yawr);
      setNodeStatesFalse(i);
    }
  }
}
 
static void getSerialData(uint8_t *bytes_received)
{
  static bool in_progress = false;
  static uint8_t var_byte;
  static uint8_t received_message[UWB_SERIAL_COMM_MAX_MESSAGE];
 
  while (external_device->char_available(external_device->periph)) {
    var_byte = UWB_SERIAL_PORT->get_byte(UWB_SERIAL_PORT->periph);
 
    if (var_byte == UWB_SERIAL_COMM_START_MARKER) {
      (*bytes_received) = 0;
      in_progress = true;
    }
 
    if (in_progress) {
      if ((*bytes_received) < UWB_SERIAL_COMM_MAX_MESSAGE - 1) {
        received_message[*bytes_received] = var_byte;
        (*bytes_received)++;
      } else {
        in_progress = false;
      }
    }
 
    if (var_byte == UWB_SERIAL_COMM_END_MARKER) {
      in_progress = false;
      decodeHighBytes(*bytes_received, received_message);
    }
  }
}
 
void decawave_anchorless_communication_init(void)
{
  // Set all nodes to false
  for (uint8_t i = 0; i < UWB_SERIAL_COMM_DIST_NUM_NODES; i++) {
    setNodeStatesFalse(i);
  }
}
 
void decawave_anchorless_communication_periodic(void)
{
  // TODO: Right now floats are sent individually, but it would be nice to send all at once (requires integrating with UWB/Arduino side as well).
  sendFloat(UWB_SERIAL_COMM_VX, stateGetSpeedEnu_f()->y);
  sendFloat(UWB_SERIAL_COMM_VY, stateGetSpeedEnu_f()->x);
  sendFloat(UWB_SERIAL_COMM_Z, stateGetPositionEnu_f()->z);
  sendFloat(UWB_SERIAL_COMM_AX, stateGetAccelNed_f()->x);
  sendFloat(UWB_SERIAL_COMM_AY, stateGetAccelNed_f()->y);
  sendFloat(UWB_SERIAL_COMM_YAWR, stateGetBodyRates_f()->r);
}
 
void decawave_anchorless_communication_event(void)
{
  static uint8_t bytes_received;
  getSerialData(&bytes_received);
  checkStatesUpdated();
}