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Permalink Responder até Jose Augusto Cintra em 16 julho 2016 at 21:11

Adir, boa noite!

Esse código vc baixou da Internet, correto?

A função que  obtém a temperatura é:

void bmp085_read_temperature_and_pressure(int* temperature, long* pressure)

Veja que a variável temperature é do tipo int, então é lógico que o resultado vai ser sem vírgulas.

Para corrigir, crie uma variável float e atribua o valor da temperatura dividido por 10.

Outra observação: Para imprimir um valor float na serial, passe como segundo parâmetro o número de casas decimais que deseja. Ao invés de DEC use 2.

Sugiro também mudar seu código para um mais simples como o do link abaixo:

https://learn.adafruit.com/bmp085/using-the-bmp085-api-v2

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Permalink Responder até Adir F.vieira em 17 julho 2016 at 23:17

Ola .

Obrigado pela atenção! Alterei , a variavel "int" por " float", e alterei onde estava int temperature , por float temperature, conforme está abaixo .De que forma eu atribuo  o float temperature e divido por 10?

#include "Wire.h"

#define I2C_ADDRESS 0x77

const unsigned char oversampling_setting = 3; //oversamplig for measurement
const unsigned char pressure_waittime[4] = { 5, 8, 14, 26 };

//just taken from the 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;
float temperature ;
void setup()
{
Serial.begin(9600); // start serial for output
Serial.println("Setting up BMP085");
Wire.begin();
bmp085_get_cal_data();
}
void bmp085_read_temperature_and_pressure(float & temperature, long& pressure);
void loop()
{
  float temperature = 0 ;
 long pressure = 0;

  bmp085_read_temperature_and_pressure(& temperature,&pressure);
Serial.print("Temperature:");
Serial.print(temperature,2);
Serial.println("deg C ");
Serial.print("pressao");
Serial.print(pressure,DEC);
Serial.println();
delay(100);
}

void bmp085_read_temperature_and_pressure(float* temperature, long* pressure) {
int ut= bmp085_read_ut();
long up = bmp085_read_up();
long x1, x2, x3, b3, b5, b6, p;
unsigned long b4, b7;

//calculate the temperature
x1 = ((long)ut - ac6) * ac5 >> 15;
x2 = ((long) mc 11) / (x1 + md);
b5 = x1 + x2;
*temperature = (b5 + 8) >> 4;

//calculate the pressure
b6 = b5 - 4000;
x1 = (b2 * (b6 * b6 >> 12)) >> 11;
x2 = ac2 * b6 >> 11;
x3 = x1 + x2;

//b3 = (((int32_t) ac1 * 4 + x3)<> 2;

if (oversampling_setting == 3) b3 = ((int32_t) ac1 * 4 + x3 + 2) 1;
if (oversampling_setting == 2) b3 = ((int32_t) ac1 * 4 + x3 + 2);
if (oversampling_setting == 1) b3 = ((int32_t) ac1 * 4 + x3 + 2) >> 1;
if (oversampling_setting == 0) b3 = ((int32_t) ac1 * 4 + x3 + 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);

}

unsigned int bmp085_read_ut() {
write_register(0xf4,0x2e);
delay(5); //longer than 4.5 ms
return read_int_register(0xf6);
}

void bmp085_get_cal_data() {
Serial.println("Reading Calibration Data");
ac1 = read_int_register(0xAA);
Serial.print("AC1: ");
Serial.println(ac1,DEC);
ac2 = read_int_register(0xAC);
Serial.print("AC2: ");
Serial.println(ac2,DEC);
ac3 = read_int_register(0xAE);
Serial.print("AC3: ");
Serial.println(ac3,DEC);
ac4 = read_int_register(0xB0);
Serial.print("AC4: ");
Serial.println(ac4,DEC);
ac5 = read_int_register(0xB2);
Serial.print("AC5: ");
Serial.println(ac5,DEC);
ac6 = read_int_register(0xB4);
Serial.print("AC6: ");
Serial.println(ac6,DEC);
b1 = read_int_register(0xB6);
Serial.print("B1: ");
Serial.println(b1,DEC);
b2 = read_int_register(0xB8);
Serial.print("B2: ");
Serial.println(b1,DEC);
mb = read_int_register(0xBA);
Serial.print("MB: ");
Serial.println(mb,DEC);
mc = read_int_register(0xBC);
Serial.print("MC: ");
Serial.println(mc,DEC);
md = read_int_register(0xBE);
Serial.print("MD: ");
Serial.println(md,DEC);
}

long bmp085_read_up() {
write_register(0xf4,0x34+(oversampling_setting6));
delay(pressure_waittime[oversampling_setting]);

unsigned char msb, lsb, xlsb;
Wire.beginTransmission(I2C_ADDRESS);
Wire.write(0xf6); // register to read
Wire.endTransmission();

Wire.requestFrom(I2C_ADDRESS, 3); // read a byte
while(!Wire.available()) {
// waiting
}
msb = Wire.read();
while(!Wire.available()) {
// waiting
}
lsb |= Wire.read();
while(!Wire.available()) {
// waiting
}
xlsb |= Wire.read();
return (((long)msb16) | ((long)lsb8) | ((long)xlsb)) >>(8-oversampling_setting);
}

void write_register(unsigned char r, unsigned char v)
{
Wire.beginTransmission(I2C_ADDRESS);
Wire.write(r);
Wire.write(v);
Wire.endTransmission();
}

char read_register(unsigned char r)
{
unsigned char v;
Wire.beginTransmission(I2C_ADDRESS);
Wire.write(r); // register to read
Wire.endTransmission();

Wire.requestFrom(I2C_ADDRESS, 1); // read a byte
while(!Wire.available()) {
// waiting
}
v = Wire.read();
return v;
}

int read_int_register(unsigned char r)
{
unsigned char msb, lsb;
Wire.beginTransmission(I2C_ADDRESS);
Wire.write(r); // register to read
Wire.endTransmission();

Wire.requestFrom(I2C_ADDRESS, 2); // read a byte
while(!Wire.available()) {
// waiting
}
msb = Wire.read();
while(!Wire.available()) {
// waiting
}
lsb = Wire.read();
return (((int)msb8) | ((int)lsb));
}

       Leitura do Serial Monitor

Setting up BMP085
Reading Calibration Data
AC1: 7768
AC2: -1097
AC3: -14561
AC4: 34080
AC5: 25194
AC6: 16268
B1: 6515
B2: 6515
MB: -32768
MC: -11786
MD: 2702
Temperature:178.00deg C
pressao102019
Temperature:178.00deg C
pressao102014
Temperature:178.00deg C
pressao102017

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Permalink Responder até Jose Augusto Cintra em 17 julho 2016 at 23:37

Adir, boa noite!

Deixe a variável temperature como int mesmo e tente o seguinte:

int temperature = 0 ;
long pressure = 0;

bmp085_read_temperature_and_pressure(& temperature,&pressure);
Serial.print("Temperature:");

float temp = (float) temperature / 10.0;

Serial.print(temp,2);

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Permalink Responder até Adir F.vieira em 18 julho 2016 at 19:58

  Jose Augusto. Boa noite!

Obrigado pela dica, testei e deu certo.

Leitura no monitor serial .

Setting up BMP085
Reading Calibration Data
AC1: 7768
AC2: -1097
AC3: -14561
AC4: 34080
AC5: 25194
AC6: 16268
B1: 6515
B2: 6515
MB: -32768
MC: -11786
MD: 2702
Altitud: 0.00 m s.n.m.
Temperature:16.70pressao102205
Altitud: 0.00 m s.n.m.
Temperature:16.70pressao102213
Altitud: 0.00 m s.n.m.

Teria mais uma dica como Ajustar os valores de altitude.

Grato.

 

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Permalink Responder até Jose Augusto Cintra em 18 julho 2016 at 20:46

Adir, boa noite!

Não vi no código que vc postou nenhuma referência ao cálculo da altitude.

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Permalink Responder até Adir F.vieira em 19 julho 2016 at 19:27

Ola Jose Augusto .

Na referencia da altitude , está mostrando a altitude Barometrica. Como poderia fazer também  para a Altitude relativa

Leitura da Da serial.

Setting up BMP085
Reading Calibration Data
AC1: 7768
AC2: -1097
AC3: -14561
AC4: 34080
AC5: 25194
AC6: 16268
B1: 6515
B2: 6515
MB: -32768
MC: -11786
MD: 2702
Temperature:16.70Pressao:101996 ALTITUDE barometrica;-55m
Temperature:16.70Pressao:101986 ALTITUDE barometrica;-54m
Temperature:16.70Pressao:101995 ALTITUDE barometrica;-55m
Temperature:16.70Pressao:101993 ALTITUDE barometrica;-55m
Temperature:16.70Pressao:101993

  #include "Wire.h"
    //unsigned long time = 0;
   float  pressao;
   float p0,P;
   int altitude;
 
  #define BMP085_ADDRESS 0x77
 
  const unsigned char oversampling_setting = 3;
  const unsigned char pressure_waittime[4] = {
  5, 8, 14, 26 };
 
  int ac1, ac2, ac3;
  unsigned int ac4, ac5, ac6;
  int b1, b2, mb, mc, md;
  int temperature=0;
  long pressure=0;
 
  double pressaoB = 101325 ;
  long b5;
 
  void setup()
{
  Serial.begin(9600); // start serial for output
  Serial.println("Setting up BMP085");
 
  Wire.begin();
 
  bmp085_get_cal_data( );
   void bmp085_read_temperature_and_pressure(int& temperature,long& pressure);
 
}
void loop()
{  
   bmp085_read_temperature_and_pressure(&temperature,& pressure);
   Serial.print("Temperature:");
   float temp =(float)temperature / 10.0;
   Serial.print(temp,2);
   Serial.print("Pressao:");
   Serial.print(pressure,DEC);
   Serial.print(" ");
   delay(5000);
  pressao=  pressure;//
  p0 = pressaoB;
 
  altitude = (float)44330 * (1 - pow(((float) pressao/p0), 0.190295));
 
  Serial.print("ALTITUDE barometrica;");
   Serial.print(altitude);
   Serial.println("m ");
}
 void bmp085_read_temperature_and_pressure(int* temperature, long* pressure) {
 int ut= bmp085_read_ut();
  long up = bmp085_read_up();
   long x1, x2, x3, b3, b5, b6, p;
    unsigned long b4, b7;

 //calculate the temperature
 x1 = ((long)ut - ac6) * ac5 >> 15;
 x2 = ((long) mc 11) / (x1 + md);
  b5 = x1 + x2;
  *temperature = (b5 + 8) >> 4;

  //calculate the pressure
  b6 = b5 - 4000;
  x1 = (b2 * (b6 * b6 >> 12)) >> 11;
  x2 = ac2 * b6 >> 11;
  x3 = x1 + x2;

 //b3 = (((int32_t) ac1 * 4 + x3)<> 2;

if (oversampling_setting == 3) b3 = ((int32_t) ac1 * 4 + x3 + 2) 1;
if (oversampling_setting == 2) b3 = ((int32_t) ac1 * 4 + x3 + 2);
if (oversampling_setting == 1) b3 = ((int32_t) ac1 * 4 + x3 + 2) >> 1;
if (oversampling_setting == 0) b3 = ((int32_t) ac1 * 4 + x3 + 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);

}

unsigned int bmp085_read_ut() {
write_register(0xf4,0x2e);
delay(5); //longer than 4.5 ms
return read_int_register(0xf6);
}

void bmp085_get_cal_data() {
Serial.println("Reading Calibration Data");
ac1 = read_int_register(0xAA);
Serial.print("AC1: ");
Serial.println(ac1,DEC);
ac2 = read_int_register(0xAC);
Serial.print("AC2: ");
Serial.println(ac2,DEC);
ac3 = read_int_register(0xAE);
Serial.print("AC3: ");
Serial.println(ac3,DEC);
ac4 = read_int_register(0xB0);
Serial.print("AC4: ");
Serial.println(ac4,DEC);
ac5 = read_int_register(0xB2);
Serial.print("AC5: ");
Serial.println(ac5,DEC);
ac6 = read_int_register(0xB4);
Serial.print("AC6: ");
Serial.println(ac6,DEC);
b1 = read_int_register(0xB6);
Serial.print("B1: ");
Serial.println(b1,DEC);
b2 = read_int_register(0xB8);
Serial.print("B2: ");
Serial.println(b1,DEC);
mb = read_int_register(0xBA);
Serial.print("MB: ");
Serial.println(mb,DEC);
mc = read_int_register(0xBC);
Serial.print("MC: ");
Serial.println(mc,DEC);
md = read_int_register(0xBE);
Serial.print("MD: ");
Serial.println(md,DEC);
}

long bmp085_read_up() {
write_register(0xf4,0x34+(oversampling_setting6));
delay(pressure_waittime[oversampling_setting]);

unsigned char msb, lsb, xlsb;
Wire.beginTransmission(BMP085_ADDRESS);
Wire.write(0xf6); // register to read
Wire.endTransmission();

Wire.requestFrom(BMP085_ADDRESS, 3); // read a byte
while(!Wire.available()) {
// waiting
}
msb = Wire.read();
while(!Wire.available()) {
// waiting
}
lsb |= Wire.read();
while(!Wire.available()) {
// waiting
}
xlsb |= Wire.read();
return (((long)msb16) | ((long)lsb8) | ((long)xlsb)) >>(8-oversampling_setting);
}

void write_register(unsigned char r, unsigned char v)
{
Wire.beginTransmission(BMP085_ADDRESS);
Wire.write(r);
Wire.write(v);
Wire.endTransmission();
}

char read_register(unsigned char r)
{
unsigned char v;
Wire.beginTransmission(BMP085_ADDRESS);
Wire.write(r); // register to read
Wire.endTransmission();

Wire.requestFrom(BMP085_ADDRESS, 1); // read a byte
while(!Wire.available()) {
// waiting
}
v = Wire.read();
return v;
}

int read_int_register(unsigned char r)
{
unsigned char msb, lsb;
Wire.beginTransmission(BMP085_ADDRESS);
Wire.write(r); // register to read
Wire.endTransmission();

Wire.requestFrom(BMP085_ADDRESS, 2); // read a byte
while(!Wire.available()) {
// waiting
}
msb = Wire.read();
while(!Wire.available()) {
// waiting
}
lsb = Wire.read();
return (((int)msb8) | ((int)lsb));
}

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