I've also tried the code below from the Sparkfun website link and I get the following:
Reading Calibration Data
AC1: 8540
AC2: -1204
AC3: -14375
AC4: 34203
AC5: 24771
AC6: 21732
B1: 5498
B2: 5498
MB: -32768
MC: -11075
MD: 2432
Temperature: -926 Pressure: 84824
Temperature: -926 Pressure: 84824
Temperature: -926 Pressure: 84824
Temperature: -926 Pressure: 84824
Temperature: -926 Pressure: 84824
Temperature: -926 Pressure: 84824
Temperature: -926 Pressure: 84824
.............
#include <Wire.h>
// From the datasheet the BMP module address LSB distinguishes
// between read (1) and write (0) operations, corresponding to
// address 0xEF (read) and 0xEE (write).
// shift the address 1 bit right (0xEF or 0xEE), the Wire library only needs the 7
// most significant bits for the address 0xEF >> 1 = 0x77
// 0xEE >> 1 = 0x77
int I2C_ADDRESS = 0x77; // sensor address
// oversampling setting
// 0 = ultra low power
// 1 = standard
// 2 = high
// 3 = ultra high resolution
const unsigned char oversampling_setting = 3; //oversampling for measurement
const unsigned char pressure_conversiontime[4] = {
5, 8, 14, 26 }; // delays for oversampling settings 0, 1, 2 and 3
// sensor registers from the BOSCH BMP085 datasheet
int ac1;
int ac2;
int ac3;
unsigned int ac4;
unsigned int ac5;
unsigned int ac6;
int b1;
int b2;
int mb;
int mc;
int md;
// variables to keep the values
int temperature = 0;
long pressure = 0;
void setup()
{
Serial.begin(9600);
Wire.begin();
getCalibrationData();
}
void loop()
{
readSensor();
Serial.print("Temperature: ");
Serial.print(temperature,DEC);
Serial.print(" Pressure: ");
Serial.println(pressure,DEC);
delay(100);
}
// Below there are the utility functions to get data from the sensor.
// read temperature and pressure from sensor
void readSensor() {
int ut= readUT();
long up = readUP();
long x1, x2, x3, b3, b5, b6, p;
unsigned long b4, b7;
//calculate true temperature
x1 = ((long)ut - ac6) * ac5 >> 15;
x2 = ((long) mc << 11) / (x1 + md);
b5 = x1 + x2;
temperature = (b5 + 8) >> 4;
//calculate true pressure
b6 = b5 - 4000;
x1 = (b2 * (b6 * b6 >> 12)) >> 11;
x2 = ac2 * b6 >> 11;
x3 = x1 + x2;
b3 = (((int32_t) ac1 * 4 + x3)<<oversampling_setting + 2) >> 2;
x1 = ac3 * b6 >> 13;
x2 = (b1 * (b6 * b6 >> 12)) >> 16;
x3 = ((x1 + x2) + 2) >> 2;
b4 = (ac4 * (uint32_t) (x3 + 32768)) >> 15;
b7 = ((uint32_t) up - b3) * (50000 >> oversampling_setting);
p = b7 < 0x80000000 ? (b7 * 2) / b4 : (b7 / b4) * 2;
x1 = (p >> 8) * (p >> 8);
x1 = (x1 * 3038) >> 16;
x2 = (-7357 * p) >> 16;
pressure = p + ((x1 + x2 + 3791) >> 4);
}
// read uncompensated temperature value
unsigned int readUT() {
writeRegister(0xf4,0x2e);
delay(5); // the datasheet suggests 4.5 ms
return readIntRegister(0xf6);
}
// read uncompensated pressure value
long readUP() {
writeRegister(0xf4,0x34+(oversampling_setting<<6));
delay(pressure_conversiontime[oversampling_setting]);
unsigned char msb, lsb, xlsb;
Wire.beginTransmission(I2C_ADDRESS);
Wire.write(0xf6); // register to read
Wire.endTransmission();
Wire.requestFrom(I2C_ADDRESS, 3); // request three bytes
while(!Wire.available()); // wait until data available
msb = Wire.read();
while(!Wire.available()); // wait until data available
lsb |= Wire.read();
while(!Wire.available()); // wait until data available
xlsb |= Wire.read();
return (((long)msb<<16) | ((long)lsb<<8) | ((long)xlsb)) >>(8-oversampling_setting);
}
void getCalibrationData() {
Serial.println("Reading Calibration Data");
ac1 = readIntRegister(0xAA);
Serial.print("AC1: ");
Serial.println(ac1,DEC);
ac2 = readIntRegister(0xAC);
Serial.print("AC2: ");
Serial.println(ac2,DEC);
ac3 = readIntRegister(0xAE);
Serial.print("AC3: ");
Serial.println(ac3,DEC);
ac4 = readIntRegister(0xB0);
Serial.print("AC4: ");
Serial.println(ac4,DEC);
ac5 = readIntRegister(0xB2);
Serial.print("AC5: ");
Serial.println(ac5,DEC);
ac6 = readIntRegister(0xB4);
Serial.print("AC6: ");
Serial.println(ac6,DEC);
b1 = readIntRegister(0xB6);
Serial.print("B1: ");
Serial.println(b1,DEC);
b2 = readIntRegister(0xB8);
Serial.print("B2: ");
Serial.println(b1,DEC);
mb = readIntRegister(0xBA);
Serial.print("MB: ");
Serial.println(mb,DEC);
mc = readIntRegister(0xBC);
Serial.print("MC: ");
Serial.println(mc,DEC);
md = readIntRegister(0xBE);
Serial.print("MD: ");
Serial.println(md,DEC);
}
void writeRegister(unsigned char r, unsigned char v)
{
Wire.beginTransmission(I2C_ADDRESS);
Wire.write(r);
Wire.write(v);
Wire.endTransmission();
}
// read a 16 bit register
int readIntRegister(unsigned char r)
{
unsigned char msb, lsb;
Wire.beginTransmission(I2C_ADDRESS);
Wire.write(r); // register to read
Wire.endTransmission();
Wire.requestFrom(I2C_ADDRESS, 2); // request two bytes
while(!Wire.available()); // wait until data available
msb = Wire.read();
while(!Wire.available()); // wait until data available
lsb = Wire.read();
return (((int)msb<<8) | ((int)lsb));
}
// read an 8 bit register
/*
unsigned char readRegister(unsigned char r)
{
unsigned char v;
Wire.beginTransmission(I2C_ADDRESS);
Wire.send(r); // register to read
Wire.endTransmission();
Wire.requestFrom(I2C_ADDRESS, 1); // request a byte
while(!Wire.available()); // wait until data available
v = Wire.receive();
return v;
}
*/