/*
 *  spreadspace avr utils - usb-bmp180 example
 *
 *
 *  Copyright (C) 2016 Bernhard Tittelbach <bernhard@tittelbach.org>
 *  basically this is refactored and enhanced code from:
 *   https://github.com/sparkfun/BMP180_Breakout_Arduino_Library
 *   Please buy the sparkfun people Beer when you see them!!!!
 *
 *  This file is part of spreadspace avr utils.
 *
 *  spreadspace avr utils 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 3 of the License, or
 *  any later version.
 *
 *  spreadspace avr utils 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 spreadspace avr utils. If not, see <http://www.gnu.org/licenses/>.
 */

#include <avr/io.h>
#include <avr/wdt.h>
#include <avr/interrupt.h>
#include <util/delay.h>
#include <stdio.h>

#include "util.h"
#include "led.h"
#include "usbio.h"

#include "Arduino.h"
#include "SFE_BMP180.h"


SFE_BMP180 pressure;

#define ALTITUDE 353.0 // Altitude of Graz in Austria


int main(void)
{
  MCUSR &= ~(1 << WDRF);
  wdt_disable();

  cpu_init();
  led_init();
  usbio_init();
  sei();

  arduino_init();

  if (pressure.begin())
    printf("BMP180 init success");
  else
  {
    // Oops, something went wrong, this is usually a connection problem,
    // see the comments at the top of this sketch for the proper connections.

    printf("BMP180 init fail\n\n");
    while(1); // Pause forever.
  }

  for(;;) {
    usbio_task();

    char status;
    double T,P,p0,a;

    // Loop here getting pressure readings every 10 seconds.

    // If you want sea-level-compensated pressure, as used in weather reports,
    // you will need to know the altitude at which your measurements are taken.
    // We're using a constant called ALTITUDE in this sketch:
    
    printf("\nprovided altitude: ");
    printf(ALTITUDE,0);
    printf(" meters, ");
    printf(ALTITUDE*3.28084,0);
    printf(" feet\n");
    
    // If you want to measure altitude, and not pressure, you will instead need
    // to provide a known baseline pressure. This is shown at the end of the sketch.

    // You must first get a temperature measurement to perform a pressure reading.
    
    // Start a temperature measurement:
    // If request is successful, the number of ms to wait is returned.
    // If request is unsuccessful, 0 is returned.

    status = pressure.startTemperature();
    if (status != 0)
    {
      // Wait for the measurement to complete:
      _delay_ms(status);

      // Retrieve the completed temperature measurement:
      // Note that the measurement is stored in the variable T.
      // Function returns 1 if successful, 0 if failure.

      status = pressure.getTemperature(T);
      if (status != 0)
      {
        // Print out the measurement:
        printf("temperature: %02d degC\n",T);
        
        // Start a pressure measurement:
        // The parameter is the oversampling setting, from 0 to 3 (highest res, longest wait).
        // If request is successful, the number of ms to wait is returned.
        // If request is unsuccessful, 0 is returned.

        status = pressure.startPressure(3);
        if (status != 0)
        {
          // Wait for the measurement to complete:
          _delay_ms(status);

          // Retrieve the completed pressure measurement:
          // Note that the measurement is stored in the variable P.
          // Note also that the function requires the previous temperature measurement (T).
          // (If temperature is stable, you can do one temperature measurement for a number of pressure measurements.)
          // Function returns 1 if successful, 0 if failure.

          status = pressure.getPressure(P,T);
          if (status != 0)
          {
            // Print out the measurement:
            printf("absolute pressure: %02d mb, %02d inHg\n", P, P*0.0295333727);

            // The pressure sensor returns abolute pressure, which varies with altitude.
            // To remove the effects of altitude, use the sealevel function and your current altitude.
            // This number is commonly used in weather reports.
            // Parameters: P = absolute pressure in mb, ALTITUDE = current altitude in m.
            // Result: p0 = sea-level compensated pressure in mb

            p0 = pressure.sealevel(P,ALTITUDE); // we're at 1655 meters (Boulder, CO)
            printf("relative (sea-level) pressure: %02d mb, %0d2 inHg", p0, p0*0.0295333727);

            // On the other hand, if you want to determine your altitude from the pressure reading,
            // use the altitude function along with a baseline pressure (sea-level or other).
            // Parameters: P = absolute pressure in mb, p0 = baseline pressure in mb.
            // Result: a = altitude in m.

            a = pressure.altitude(P,p0);
            printf("computed altitude: %dm\n",a);
          }
          else printf("error retrieving pressure measurement\n");
        }
        else printf("error starting pressure measurement\n");
      }
      else printf("error retrieving temperature measurement\n");
    }
    else printf("error starting temperature measurement\n");

    _delay_ms(5000);  // Pause for 5 seconds.

  }
}