BMP085 trykmåler

#include <Wire.h>
#include <bmp085.h>

/*
1. call bmp085_init
   - parameter pressure at sealevel (in Pascal) or 0
     if 0 then 101325 (std pressure at sea level) is used

2. Measurement by
  a. call bmp085_measure()
  b. now pressure and temperature is in float variables bmp085_temp and bmp085_pres
*/


void setup()
{
  Serial.begin(115200);
  Wire.begin();

  bmp085Init(0x77,101300.0); // ress at sealevel today  - contact local met office :-)
                             // i2c addr is 0x76 or 0x77 use i2cscannermpu6050 to check
}

float temp, atm, alt, pres;


#define LOOPTIME 200
unsigned long t1, t3;

void loop()
{
float tryk, temp, hojde;
  bmp085Measure(&temp, &tryk, &hojde);

  Serial.print("temp(C) "); Serial.print(temp);
  Serial.print("\t tryk(Pa) "); Serial.print(tryk);
  Serial.print("\t hojde(m)"); Serial.println(hojde);
  delay(100);
}

#include <Wire.h>
#include <bmp085.h>

// NB NB find atm pressure at sealevel for today and adjust SEALEVEL below

#define SEALEVEL 102320.0

// ---

#define LOOPTIME 5
#define AVERSIZE 20

float ff[AVERSIZE];

void initAverageArray()
{
  static float pres, temp, alt;
  for (int i = 0; i < AVERSIZE; i++) {  // do AVERSIZE start measurements
    bmp085Measure(&temp, &pres, &alt);
    delay(LOOPTIME);
    ff[i] = alt;
  }
}

float calcAverage(float ff[])
{
  float mean = 0.0;

  for (int i = 0; i < AVERSIZE; i++)
    mean += ff[i];

  return (mean / AVERSIZE);
}

void setup()
{
  Serial.begin(115200);
  Wire.begin();
  delay(10);

  bmp085Init(0x77,SEALEVEL); // ress at sealevel today 0x76 or 0x77
  delay(10);

  initAverageArray();
}


void loop()
{
  // placed here with static to guard by use of scoperules
  static int index = 0;

  static float pres, temp, alt;
  static float averageAltitude;


  bmp085Measure(&temp, &pres, &alt);
  // overwrite oldest value
  ff[index] = alt;
  index++;
  if (AVERSIZE <= index)  // wrap around
    index = 0;


  averageAltitude = calcAverage(ff);

  Serial.print(alt); Serial.print(" ");
  Serial.println(averageAltitude);
  delay(LOOPTIME);
}

 /* ende */