downlink.c

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/*
 * Copyright (C) 2006 Pascal Brisset, Antoine Drouin
 *
 * 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, write to
 * the Free Software Foundation, 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 */
 
#include "modules/datalink/downlink.h"
 
#if (defined DATALINK) || PERIODIC_TELEMETRY
#include "modules/datalink/datalink.h"
#endif
 
#if PERIODIC_TELEMETRY
#include "modules/datalink/telemetry.h"
#include "mcu_periph/sys_time.h"
 
static uint32_t last_down_nb_bytes = 0;  // previous number of bytes sent
static uint32_t last_up_nb_msgs = 0;  // previous number of received messages
static uint32_t last_ts = 0;  // timestamp in usec when last message was send
 
static void send_downlink(struct transport_tx *trans, struct link_device *dev)
{
  // current timestamp
  uint32_t now_ts = get_sys_time_msec();
  // compute downlink byte rate
  if (now_ts > last_ts) {
    uint16_t down_rate = (1000 * ((uint32_t)dev->nb_bytes - last_down_nb_bytes)) / (now_ts - last_ts);
    uint16_t up_rate = (1000 * ((uint32_t)datalink_nb_msgs - last_up_nb_msgs)) / (now_ts - last_ts);
 
    last_ts = now_ts;
#if defined DATALINK || defined SITL
    last_down_nb_bytes = dev->nb_bytes;
    last_up_nb_msgs = datalink_nb_msgs;
#else
    last_down_nb_bytes = 0;
    last_up_nb_msgs = 0;
#endif
 
    pprz_msg_send_DATALINK_REPORT(trans, dev, AC_ID, &datalink_time, &datalink_nb_msgs, &dev->nb_msgs, &down_rate,
                                  &up_rate, &dev->nb_ovrn);
  }
}
#endif
 
void downlink_init(void)
{
  // Set initial counters
  (DefaultDevice).device.nb_ovrn = 0;
  (DefaultDevice).device.nb_bytes = 0;
  (DefaultDevice).device.nb_msgs = 0;
 
#if defined DATALINK
  datalink_nb_msgs = 0;
#endif
 
#if PERIODIC_TELEMETRY
  register_periodic_telemetry(DefaultPeriodic, PPRZ_MSG_ID_DATALINK_REPORT, send_downlink);
#endif
}