osd-contiki/examples/osd/arduino-weather/Barometer.cpp

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2016-05-20 11:18:19 +02:00
/*
Barometer library V1.0
2010 Copyright (c) Seeed Technology Inc. All right reserved.
Original Author: LG
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "Barometer.h"
#include <Wire.h>
#include <Arduino.h>
void Barometer::init(void)
{
Wire.begin();
// Serial.print("Temperaturet: ");
ac1 = bmp085ReadInt(0xAA);
ac2 = bmp085ReadInt(0xAC);
ac3 = bmp085ReadInt(0xAE);
ac4 = bmp085ReadInt(0xB0);
ac5 = bmp085ReadInt(0xB2);
ac6 = bmp085ReadInt(0xB4);
b1 = bmp085ReadInt(0xB6);
b2 = bmp085ReadInt(0xB8);
mb = bmp085ReadInt(0xBA);
mc = bmp085ReadInt(0xBC);
md = bmp085ReadInt(0xBE);
// Serial.print("Temperaturet2: ");
}
// Read 1 byte from the BMP085 at 'address'
// Return: the read byte;
char Barometer::bmp085Read(unsigned char address)
{
//Wire.begin();
//unsigned char data;
Wire.beginTransmission(BMP085_ADDRESS);
Wire.write(address);
Wire.endTransmission();
Wire.requestFrom(BMP085_ADDRESS, 1);
while(!Wire.available());
return Wire.read();
}
// Read 2 bytes from the BMP085
// First byte will be from 'address'
// Second byte will be from 'address'+1
int Barometer::bmp085ReadInt(unsigned char address)
{
unsigned char msb, lsb;
Wire.beginTransmission(BMP085_ADDRESS);
Wire.write(address);
Wire.endTransmission();
Wire.requestFrom(BMP085_ADDRESS, 2);
while(Wire.available()<2);
msb = Wire.read();
lsb = Wire.read();
return (int) msb<<8 | lsb;
}
// Read the uncompensated temperature value
unsigned int Barometer::bmp085ReadUT()
{
unsigned int ut;
Wire.beginTransmission(BMP085_ADDRESS);
Wire.write(0xF4);
Wire.write(0x2E);
Wire.endTransmission();
delay(5);
ut = bmp085ReadInt(0xF6);
return ut;
}
// Read the uncompensated pressure value
unsigned long Barometer::bmp085ReadUP()
{
unsigned char msb, lsb, xlsb;
unsigned long up = 0;
Wire.beginTransmission(BMP085_ADDRESS);
Wire.write(0xF4);
Wire.write(0x34 + (OSS<<6));
Wire.endTransmission();
delay(2 + (3<<OSS));
// Read register 0xF6 (MSB), 0xF7 (LSB), and 0xF8 (XLSB)
msb = bmp085Read(0xF6);
lsb = bmp085Read(0xF7);
xlsb = bmp085Read(0xF8);
up = (((unsigned long) msb << 16) | ((unsigned long) lsb << 8) | (unsigned long) xlsb) >> (8-OSS);
return up;
}
void Barometer::writeRegister(int deviceAddress, byte address, byte val)
{
Wire.beginTransmission(deviceAddress); // start transmission to device
Wire.write(address); // send register address
Wire.write(val); // send value to write
Wire.endTransmission(); // end transmission
}
int Barometer::readRegister(int deviceAddress, byte address)
{
int v;
Wire.beginTransmission(deviceAddress);
Wire.write(address); // register to read
Wire.endTransmission();
Wire.requestFrom(deviceAddress, 1); // read a byte
while(!Wire.available()) {
// waiting
}
v = Wire.read();
return v;
}
float Barometer::calcAltitude(float pressure)
{
float A = pressure/101325;
float B = 1/5.25588;
float C = pow(A,B);
C = 1 - C;
C = C /0.0000225577;
return C;
}
float Barometer::bmp085GetTemperature(unsigned int ut)
{
long x1, x2;
x1 = (((long)ut - (long)ac6)*(long)ac5) >> 15;
x2 = ((long)mc << 11)/(x1 + md);
PressureCompensate = x1 + x2;
float temp = ((PressureCompensate + 8)>>4);
temp = temp /10;
return temp;
}
long Barometer::bmp085GetPressure(unsigned long up)
{
long x1, x2, x3, b3, b6, p;
unsigned long b4, b7;
b6 = PressureCompensate - 4000;
x1 = (b2 * (b6 * b6)>>12)>>11;
x2 = (ac2 * b6)>>11;
x3 = x1 + x2;
b3 = (((((long)ac1)*4 + x3)<<OSS) + 2)>>2;
// Calculate B4
x1 = (ac3 * b6)>>13;
x2 = (b1 * ((b6 * b6)>>12))>>16;
x3 = ((x1 + x2) + 2)>>2;
b4 = (ac4 * (unsigned long)(x3 + 32768))>>15;
b7 = ((unsigned long)(up - b3) * (50000>>OSS));
if (b7 < 0x80000000)
p = (b7<<1)/b4;
else
p = (b7/b4)<<1;
x1 = (p>>8) * (p>>8);
x1 = (x1 * 3038)>>16;
x2 = (-7357 * p)>>16;
p += (x1 + x2 + 3791)>>4;
long temp = p;
return temp;
}