c - 将读数传感器作为消息发送到接收节点

Question

我在 upd-sink.c 工作和udp-sender.c contiki/examples/ipv6/rpl-collect 的示例Cooja 的路径。我希望发送者节点将其传感器数据发送到接收器。在 udp-sender.c代码，有一个struct叫msg还有这个struct有一个名为 msg 的数据字段其类型为struct collect_view_data_msg类型。我想将我的读数传感器放入 msg 中并发送到接收器。我该怎么做？我有一个检测温度的程序。我要发送s可变为按摩下沉。我想在 Cooja 中模拟这个网络。

传感器程序:

PROCESS(sensor_acq_process,"Sensor Acquisition");
AUTOSTART_PROCESSES(&sensor_acq_process);
PROCESS_THREAD(sensor_acq_process,ev,data)
{ 
  static struct etimer et;
  static int val;
  static float s = 0;
  static int dec;
  static float frac;

  PROCESS_BEGIN();

  printf("Starting Sensor Example.\n");

  while(1)
  {
   etimer_set(&et, CLOCK_SECOND * 2);
   SENSORS_ACTIVATE(sht11_sensor);

   PROCESS_WAIT_EVENT_UNTIL(etimer_expired(&et));

   val = sht11_sensor.value(SHT11_SENSOR_TEMP);
   if(val != -1) 
   {
     s = ((0.01*val) - 39.60);
     dec = s;
     frac = s - dec;
     printf("\nTemperature=%d.%02u C (%d)\n", dec, (unsigned int)(frac * 100),val);               
    }       

    etimer_reset(&et);
    SENSORS_DEACTIVATE(light_sensor);
    SENSORS_DEACTIVATE(sht11_sensor);
  } //end of while

  PROCESS_END();
}

函数collect-common-send的udp-sender.c程序:

 void collect_common_send(void)
{
  static uint8_t seqno;
  struct {
    uint8_t seqno;
    uint8_t for_alignment;
    struct collect_view_data_msg msg;
  } msg;
  /* struct collect_neighbor *n; */
  uint16_t parent_etx;
  uint16_t rtmetric;
  uint16_t num_neighbors;
  uint16_t beacon_interval;
  rpl_parent_t *preferred_parent;
  linkaddr_t parent;
  rpl_dag_t *dag;
  if(client_conn == NULL) {
    /* Not setup yet */
    return;
  }
  memset(&msg, 0, sizeof(msg));
  seqno++;
  if(seqno == 0) {
    /* Wrap to 128 to identify restarts */
    seqno = 128;
  }
  msg.seqno = seqno;

  linkaddr_copy(&parent, &linkaddr_null);
  parent_etx = 0;

  /* Let's suppose we have only one instance */
  dag = rpl_get_any_dag();
  if(dag != NULL) {
    preferred_parent = dag->preferred_parent;
    if(preferred_parent != NULL) {
      uip_ds6_nbr_t *nbr;
      nbr = uip_ds6_nbr_lookup(rpl_get_parent_ipaddr(preferred_parent));
      if(nbr != NULL) {
        /* Use parts of the IPv6 address as the parent address, in reversed byte order. */
        parent.u8[LINKADDR_SIZE - 1] = nbr->ipaddr.u8[sizeof(uip_ipaddr_t) - 2];
        parent.u8[LINKADDR_SIZE - 2] = nbr->ipaddr.u8[sizeof(uip_ipaddr_t) - 1];
        parent_etx = rpl_get_parent_rank((uip_lladdr_t *) uip_ds6_nbr_get_ll(nbr)) / 2;
      }
    }
    rtmetric = dag->rank;
    beacon_interval = (uint16_t) ((2L << dag->instance->dio_intcurrent) / 1000);
    num_neighbors = uip_ds6_nbr_num();
  } 
  else {
    rtmetric = 0;
    beacon_interval = 0;
    num_neighbors = 0;
  }

  /* num_neighbors = collect_neighbor_list_num(&tc.neighbor_list); */
  collect_view_construct_message(&msg.msg, &parent,
      parent_etx, rtmetric,
      num_neighbors, beacon_interval);
  //i add this code but it led to an error:invalid type argument
  //of'->'(have 'struct collect_view_data_msg')

  SENSORS_ACTIVATE(sht11_sensor);
  msg.msg->sensors[TEMP_SENSOR] = sht11_sensor.value(SHT11_SENSOR_TEMP);
  //end added

  uip_udp_packet_sendto(client_conn, &msg, sizeof(msg),
      &server_ipaddr, UIP_HTONS(UDP_SERVER_PORT));

  SENSORS_DEACTIVATE(sht11_sensor);
}

Answer 1

您在 Cooja 中使用哪个平台？ (最有可能 sky 。)

1. 如果平台是 sky，则传感器读数已包含在收集 View 消息中。如果不是，收集apps/collect-view/下的查看代码可以很容易地扩展使用 collect-view-template.c 来做到这一点作为基础。
2. 不要使用floating point numbers on embedded systems .
3. 如果您真的知道自己在做什么，想要使用浮点，并且希望拥有 ASCII 格式的数据，请在 struct collect_view_data_msg 中创建新字段。那是 char数组，和 snprintf该字段中传感器的值。

作为一个小注释，不需要此代码:

SENSORS_ACTIVATE(sht11_sensor);
msg.msg->sensors[TEMP_SENSOR] = sht11_sensor.value(SHT11_SENSOR_TEMP);
...
SENSORS_DEACTIVATE(sht11_sensor);

如上所述，sht11_sensor已阅读并包含在收集 View 应用程序的消息中。