baro_board.c

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/*
* Copyright (C) 2010 ENAC
*
* 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.
*
*/


/* driver for the analog Barometer Mpxa6115 using ADC ads1114 (16 bits I2C 860SpS max) from Texas instruments
 * Navarro & Gorraz & Hattenberger
 */

#include "std.h"
#include "baro_board.h"
#include "subsystems/sensors/baro.h"
#include "peripherals/mcp355x.h"
#include "subsystems/abi.h"
#include "led.h"

#ifndef NAVGO_BARO_SENS
#define NAVGO_BARO_SENS 0.05298
#endif

#ifndef NAVGO_BARO_OFFSET
#define NAVGO_BARO_OFFSET 199229
#endif

/* Counter to init mcp355x at startup */
#define BARO_STARTUP_COUNTER 200
uint16_t startup_cnt;

void baro_init(void)
{
  mcp355x_init();
#ifdef BARO_LED
  LED_OFF(BARO_LED);
#endif
  startup_cnt = BARO_STARTUP_COUNTER;
}

void baro_periodic(void)
{
  // Run some loops to get correct readings from the adc
  if (startup_cnt > 0) {
    --startup_cnt;
#ifdef BARO_LED
    LED_TOGGLE(BARO_LED);
    if (startup_cnt == 0) {
      LED_ON(BARO_LED);
    }
#endif
  }
  // Read the ADC (at 50/4 Hz, conversion time is 68 ms)
  RunOnceEvery(4, mcp355x_read());
}

void navgo_baro_event(void)
{
  mcp355x_event();
  if (mcp355x_data_available) {
    if (startup_cnt == 0) {
      // Send data when init phase is done
      uint32_t now_ts = get_sys_time_usec();
      float pressure = NAVGO_BARO_SENS * (mcp355x_data + NAVGO_BARO_OFFSET);
      AbiSendMsgBARO_ABS(BARO_BOARD_SENDER_ID, now_ts, pressure);
    }
    mcp355x_data_available = false;
  }
}