#include <xc.h>
#include <stdio.h>
#include <stdlib.h>
#include "delay.h"
#include <delays.h>
#include "i2c.h"
#define SDA_PIN PORTBbits.RB1 //
#define SCL_PIN PORTBbits.RB4 //
#define SDA_DIR TRISBbits.TRISB1
#define SCL_DIR TRISBbits.TRISB4
// Common I2C Routines
void i2c_restart(void)
{
i2c_low_scl(); /* ensure clock is low */
i2c_high_scl(); /* ensure data is high */
SCL_DIR = 1; /* clock pulse high */
i2c_low_sda(); /* the high->low transition */
return;
}
void i2c_read(unsigned short r_byte)
{
int n;
i2c_high_sda();
for (n=0; n<8; n++)
{
i2c_high_scl();
if (SDA_PIN)
{
r_byte = (r_byte << 1) | 0x01; // msbit first
}
else
{
r_byte = r_byte << 1;
}
i2c_low_scl();
}
return;
}
void i2c_write(signed char w_byte)
{
int m ;
for(m=0; m<8; m++)
{
if(w_byte&0x80)
{
i2c_high_sda();
}
else
{
i2c_low_sda();
}
i2c_high_scl();
i2c_low_scl();
w_byte = w_byte << 1;
}
i2c_high_sda();
}
void i2c_nack(void)
{
i2c_high_sda(); // data at one
i2c_high_scl(); // clock pulse
i2c_low_scl();
}
void i2c_ack(void)
{
i2c_low_sda(); // bring data low and clock
i2c_high_scl();
i2c_low_scl();
i2c_high_sda();
}
void i2c_start(void)
{
i2c_low_scl();
i2c_high_sda();
i2c_high_scl(); // bring SDA low while SCL is high
i2c_low_sda();
i2c_low_scl();
}
void i2c_stop(void)
{
i2c_low_scl();
i2c_low_sda();
i2c_high_scl();
i2c_high_sda(); // bring SDA high while SCL is high
// idle is SDA high and SCL high
}
void i2c_high_sda(void)
{
// bring SDA to high impedance
SDA_DIR = 1;
DelayUs(5);
}
void i2c_low_sda(void)
{
SDA_PIN = 0;
SDA_DIR = 0; // output a hard logic zero
DelayUs(5);
}
void i2c_high_scl(void)
{
SCL_DIR = 1; // high impedance
DelayUs(5);
}
void i2c_low_scl(void)
{
SCL_PIN = 0;
SCL_DIR = 0;
DelayUs(5);
}
/************************************************************************
* Defines ***** Definiciones *
************************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include "delay.h"
#include <delays.h>
#include <xc.h>
#include "BMP085.h"
#define BMP085_R 0xEF // Write address
#define BMP085_W 0xEE // Read address
#define OSS 0 // Oversampling Setting
/************************************************************************
* Globar Vars and Constants ***** Variables y Constates globales *
************************************************************************/
const unsigned char OSS_conversion_time[] = {5, 8, 14, 26};
signed short ac1;
signed short ac2;
signed short ac3;
signed short b1;
signed short b2;
signed short mb;
signed short mc;
signed short md;
unsigned short ac4;
unsigned short ac5;
unsigned short ac6;
signed char but,bup;
unsigned char shift;
/************************************************************************
* Function Prototypes *
************************************************************************/
void BMP085_Calibration(void);
long bmp085Read2Bytes(unsigned char address);
unsigned long bmp085Read3Bytes(unsigned char address);
long bmp085ReadTemp(void);
long bmp085ReadPressure(void);
void bmp085Convert(long *temperature, long *pressure,unsigned char readings);
/************************************************************************
* *
* Purpose: Will read two (or 3) sequential 8-bit registers, *
* and Return a 16-bit value. *
* Proposito: Leer 2 registros de 8 bits secuenciales y regresar *
* un valor de 16bits. *
* Passed: Address - Unsigned char *
* Argumento: Direccion *
* Returned: Reading - Long *
* Retorno: Lectura *
* Note: Return value must be typecast to an signed short *
* if reading a signed value! *
* *
************************************************************************/
long bmp085Read2Bytes(unsigned char address)
{
unsigned short msb, lsb;
long data=0;
delay_ms(10);
i2c_start();
i2c_write(BMP085_W); // Escribir la direccion del sensor
i2c_write(address); // Direccion de memoria
i2c_start(); // Reinicio
i2c_write(BMP085_R); // Direccion para leer del sensor
msb = i2c_read(0); // Leer la direccion
delay_ms(10);
i2c_stop(); // Parar
delay_ms(10);
i2c_start();
i2c_write(BMP085_W); // Write required to clock in address
i2c_write(address+1); // Mem address
i2c_start(); // Restart
i2c_write(BMP085_R); // Device address for reading
lsb=i2c_read(0); // Read address
delay_ms(10);
i2c_stop(); // Stop
data = msb << 8;
data = data | lsb;
return data;
}
unsigned long bmp085Read3Bytes(unsigned char address)
{
unsigned short msb,lsb,xlsb;
unsigned long data=0;
delay_ms(10);
i2c_start();
i2c_write(BMP085_W); // Escribir la direccion del sensor
i2c_write(address); // Direccion de memoria
i2c_start(); // Reinicio
i2c_write(BMP085_R); // Direccion para leer del sensor
msb=i2c_read(0); // Leer la direccion
delay_ms(10);
i2c_stop(); // Parar
delay_ms(10);
i2c_start();
i2c_write(BMP085_W); // Write required to clock in address
i2c_write(address+1); // Mem address
i2c_start(); // Restart
i2c_write(BMP085_R); // Device address for reading
lsb=i2c_read(0); // Read address
delay_ms(10);
i2c_stop(); // Stop
delay_ms(10);
i2c_start();
i2c_write(BMP085_W); // Write required to clock in address
i2c_write(address+2); // Mem address
i2c_start(); // Restart
i2c_write(BMP085_R); // Device address for reading
xlsb=i2c_read(0); // Read address
delay_ms(10);
i2c_stop(); // Stop
data = (msb << 8);
data = (data | lsb);
data = (data << 8);
data = (data | xlsb);
data = (data >> (8-OSS));
return data;
}
/************************************************************************
*
* Purpose: Calibrates the BMP085 pressure sensor.
* Passed: Void
* Returned: Void
* Note:
*
************************************************************************/
void BMP085_Calibration(void)
{
/* ac1 = 6690;
ac2 = -1227;
ac3 = -14421;
ac4 = 33898;
ac5 = 24422;
ac6 = 22886;
b1 = 5498;
b2 = 66;
mb = -32768;
mc = -11075;
md = 2432;
*/
ac1 = bmp085Read2Bytes(0xAA);
ac2 = bmp085Read2Bytes(0xAC);
ac3 = bmp085Read2Bytes(0xAE);
ac4 = bmp085Read2Bytes(0xB0);
ac5 = bmp085Read2Bytes(0xB2);
ac6 = bmp085Read2Bytes(0xB4);
b1 = bmp085Read2Bytes(0xB6);
b2 = bmp085Read2Bytes(0xB8);
mb = bmp085Read2Bytes(0xBA);
mc = bmp085Read2Bytes(0xBC);
md = bmp085Read2Bytes(0xBE);
/*
printf("%Ld \n",ac1);
printf("%Ld \n",ac2);
printf("%Ld \n",ac3);
printf("%Lu \n",ac4);
printf("%Lu \n",ac5);
printf("%Lu \n",ac6);
printf("%Ld \n",b1);
printf("%Ld \n",b2);
printf("%Ld \n",mb);
printf("%Ld \n",mc);
printf("%Ld \n",md);
*/
}
/************************************************************************
*
* Purpose: Will read the 16-bit temperature value of BMP085 sensor.
* Passed: Void
* Returned: Long
* Note:
*
************************************************************************/
long bmp085ReadTemp(void)
{
i2c_start();
i2c_write(BMP085_W); // Write 0xEE
i2c_write(0xF4); // Write register address
i2c_write(0x2E); // Write register data for temp
i2c_stop();
delay_ms(10); // Max time is 4.5ms
return bmp085Read2Bytes(0xF6);
}
/************************************************************************
*
* Purpose: Will read the 16-bit pressure value from BMP085 sensor.
* Passed: Void
* Returned: Long
* Note:
*
************************************************************************/
unsigned long bmp085ReadPressure(void)
{
i2c_start();
i2c_write(BMP085_W); // Write 0xEE
i2c_write(0xF4); // Write register address
i2c_write(0x34 | (OSS << 6)); // Write register data for temp
i2c_stop();
delay_ms(OSS_conversion_time[OSS]); // Max time is 4.5ms
return bmp085Read3Bytes(0xF6);
}
/************************************************************************
*
* Purpose: Will find callibrated pressure + temperature
* Passed: Long *temperature, long *pressure, unsigned char readings
* Returned: Void
* Note:
*
************************************************************************/
// The bit-shift for possibly negative numbers.
// Note that divide has a higher precedence than
// bit shift, so this is not precisely the same.
void bmp085Convert(float *temperature, float *pressure)
{
unsigned long ut,up;
//float32 b5, b6, x3, b3, p, b4, b7;
signed long aux1,aux2,aux3,aux4;
signed long c3,c4,c5,c6,bb1,mmc,mmd,x,x0,x1,x2,y,y0,y1,y2,p0,p1,p2,z,s,alpha,temp,pres;
ut = bmp085ReadTemp();
ut = bmp085ReadTemp();
up = bmp085ReadPressure();
up = bmp085ReadPressure();
//ut = 0x7B50;
//up = 0x883F;
//printf("%LX \n",ut);
//printf("%LX \n",up);
//but = ut; //Debug var
/*NEW CALCS*/
c3 = 160*pow(2,-15)*ac3;
c4 = pow(10,-3)*pow(2,-15)*ac4;
bb1 = 25600*pow(2,-30)*b1;
//printf("%e \n",c3);
//printf("%e \n",c4);
//printf("%e \n",bb1);
c5 = ac5*pow(2,-15)/160;
c6 = ac6;
mmc = (0.08)*mc;
mmd = md/160;
//printf("%e \n",c5);
//printf("%e \n",c6);
//printf("mmc\n");
//printf("%e \n",mmc);
//printf("%e \n",mmd);
x0 = ac1;
x1 = 160*pow(2,-13)*ac2;
x2 = 25600*pow(2,-25)*b2;
//printf("%e \n",x0);
//printf("%e \n",x1);
//printf("%e \n",x2);
y0 = c4*32768;
y1 = c4*c3;
y2 = c4*bb1;
//printf("%e \n",y0);
//printf("%e \n",y1);
//printf("%e \n",y2);
p0 = 3783/1600;
p1 = 1-7357*pow(2,-20);
p2 = 3038*100*pow(2,-36);
//printf("%e \n",p0);
//printf("%e \n",p1);
//printf("%e \n",p2);
/*Calculamos temperatura*/
alpha = c5*(ut-c6);
temp = alpha + (mmc/(alpha+mmd));
/*Calculamos presion*/
s = temp - 25;
x = x2*s*s+x1*s+x0;
y = y2*s*s+y1*s+y0;
z = (up-x)/y;
pres = p2*z*z+p1*z+p0;
*temperature = temp;
*pressure = pres;
/**/
/****************BEGIN*****CALC*****TEMP*********************/
/*
aux1 = ut-ac6;
aux2 = aux1*ac5;
x1 = aux2/32768;
//x1 = ((ut - ac6) * ac5 / pow(2,15));
aux3 = x1+md;
aux4 = mc/aux3;
x2 = aux4*2048;
//x2 = (mc * (pow(2,11))) / (x1 + md);
b5 = x1 + x2;
*temperature = ((b5 + 8) / 16);
/****************END*****CALC*****TEMP***********************/
/****************BEGIN*****CALC*****PRES*********************/
/*
up = up >> (8-OSS);
//bup = up; //Debug var
b6 = b5 - 4000;
aux1 = b6*b6;
aux2 = aux1/4096;
aux3 = aux2*b2;
x1 = aux3/2048;
//x1 = (b2 * (b6 * b6 / pow(2,12))) / pow(2,11);
aux1 = ac2*b6;
x2 = aux1/2048;
//x2 = ac2 * b6 / pow(2,11);
x3 = x1 + x2;
aux1 = ac1*4;
aux2 = aux1+x3;
shift = aux2;
aux3 = shift << OSS;
aux4 = aux3+2;
b3 = aux4/4;
//b3 = ((((ac1 * 4) + x3) << OSS) + 2) / 4;
aux1 = ac3*b6;
x1 = aux1/8192;
//x1 = ac3 * b6 / pow(2,13);
aux1 = b6*b6;
aux2 = aux1/4096;
aux3 = aux2*b1;
x2 = aux3/65536;
//x2 = (b1 * (b6 * b6 / pow(2,12))) / pow(2,16);
aux1 = x1+x2+2;
x3 = aux1/4;
//x3 = ((x1 + x2) + 2) / pow(2,2);
aux1 = x3+32768;
aux2 = ac4*aux1;
b4 = aux2/32768;
//b4 = (ac4 * (unsigned long) (x3 + 32768)) / pow(2,15);
aux1 = up-b3;
aux2 = 50000>>OSS;
b7 = aux1*aux2;
//b7 = ((unsigned long) up - b3) * (50000 >> OSS);
if (b7 < 0x80000000)
{
aux1 = b7*2;
p = aux1/b4;
}
else
{
aux1 = b7/b4;
p = aux1*2;
}
aux1 = p/256;
x1 = aux1*aux1;
//x1 = p / pow(2,8);
//x1 *= x1;
aux2 = x1*3038;
x1 = aux2/65536;
//x1 = (x1 * 3038) / pow(2,16);
aux1 = -7357*p;
x2 = aux1/65536;
//x2 = (-7357 * p) / pow(2,16);
aux1 = x1+x2+3791;
aux2 = aux1/16;
p = p+aux2;
*pressure = p;
/****************END*****CALC*****PRES***********************/
}
Rseliman, estoy releyendo tus post y me encuentro con una duda... ¿las rutinas de I2C las has hecho tu?
Me parece que hay un error. De hecho, creo que i2c_read() nunca funcionaría. Sinceramente me has hecho dudar :oops: pero creo que la única forma que tiene una función para devolver un valor es definiendola para que devuelva
por ejemploCódigo: C
o manejar una variable global y modificarla dentro de la función.
/************************************************************************
* *
* Module: BMP085.c *
* Description: BMP085-specific code. *
* *
* *
* Date: Authors: Comments: *
* 18 Feb 2012 Jose Morales Created *
* *
* *
************************************************************************/
/************************************************************************
* Defines ***** Definiciones *
************************************************************************/
#include "math.h"
#include "i2c.h"
#define BMP085_R 0xEF // Write address
#define BMP085_W 0xEE // Read address
#define OSS 0 // Oversampling Setting
/************************************************************************
* Globar Vars and Constants ***** Variables y Constates globales *
************************************************************************/
const unsigned char OSS_conversion_time[] = {5, 8, 14, 26};
signed short ac1;
signed short ac2;
signed short ac3;
signed short b1;
signed short b2;
signed short mb;
signed short mc;
signed short md;
unsigned short ac4;
unsigned short ac5;
unsigned short ac6;
signed char but,bup;
unsigned char shift;
/************************************************************************
* Function Prototypes *
************************************************************************/
//void BMP085_Calibration(void);
//long bmp085Read2Bytes(unsigned char address);
//unsigned long bmp085Read3Bytes(unsigned char address);
//long bmp085ReadTemp(void);
//unsigned long bmp085ReadPressure(void);
//void bmp085Convert(signed long *temperature, signed long *pressure);
/************************************************************************
* *
* Purpose: Will read two (or 3) sequential 8-bit registers, *
* and Return a 16-bit value. *
* Proposito: Leer 2 registros de 8 bits secuenciales y regresar *
* un valor de 16bits. *
* Passed: Address - Unsigned char *
* Argumento: Direccion *
* Returned: Reading - Long *
* Retorno: Lectura *
* Note: Return value must be typecast to an signed short *
* if reading a signed value! *
* *
************************************************************************/
long bmp085Read2Bytes(unsigned char address)
{
unsigned short msb, lsb;
msb,lsb = 0;
long data=0;
delay_ms(10);
i2c_start();
i2c_write(BMP085_W); // Escribir la direccion del sensor
i2c_write(address); // Direccion de memoria
i2c_start(); // Reinicio
i2c_write(BMP085_R); // Direccion para leer del sensor
i2c_read(msb); // Leer la direccion
delay_ms(10);
i2c_stop(); // Parar
delay_ms(10);
i2c_start();
i2c_write(BMP085_W); // Write required to clock in address
i2c_write(address+1); // Mem address
i2c_start(); // Restart
i2c_write(BMP085_R); // Device address for reading
i2c_read(lsb); // Read address
delay_ms(10);
i2c_stop(); // Stop
data = msb << 8;
data = data | lsb;
return data;
}
unsigned long bmp085Read3Bytes(unsigned char address)
{
unsigned short msb,lsb,xlsb;
unsigned long data=0;
delay_ms(10);
i2c_start();
i2c_write(BMP085_W); // Escribir la direccion del sensor
i2c_write(address); // Direccion de memoria
i2c_start(); // Reinicio
i2c_write(BMP085_R); // Direccion para leer del sensor
i2c_read(msb); // Leer la direccion
delay_ms(10);
i2c_stop(); // Parar
delay_ms(10);
i2c_start();
i2c_write(BMP085_W); // Write required to clock in address
i2c_write(address+1); // Mem address
i2c_start(); // Restart
i2c_write(BMP085_R); // Device address for reading
i2c_read(lsb); // Read address
delay_ms(10);
i2c_stop(); // Stop
delay_ms(10);
i2c_start();
i2c_write(BMP085_W); // Write required to clock in address
i2c_write(address+2); // Mem address
i2c_start(); // Restart
i2c_write(BMP085_R); // Device address for reading
i2c_read(xlsb); // Read address
delay_ms(10);
i2c_stop(); // Stop
data = (msb << 8);
data = (data | lsb);
data = (data << 8);
data = (data | xlsb);
data = (data >> (8-OSS));
return data;
}
/************************************************************************
*
* Purpose: Calibrates the BMP085 pressure sensor.
* Passed: Void
* Returned: Void
* Note:
*
************************************************************************/
void BMP085_Calibration(void)
{
/* ac1 = 6690;
ac2 = -1227;
ac3 = -14421;
ac4 = 33898;
ac5 = 24422;
ac6 = 22886;
b1 = 5498;
b2 = 66;
mb = -32768;
mc = -11075;
md = 2432;
*/
ac1 = bmp085Read2Bytes(0xAA);
ac2 = bmp085Read2Bytes(0xAC);
ac3 = bmp085Read2Bytes(0xAE);
ac4 = bmp085Read2Bytes(0xB0);
ac5 = bmp085Read2Bytes(0xB2);
ac6 = bmp085Read2Bytes(0xB4);
b1 = bmp085Read2Bytes(0xB6);
b2 = bmp085Read2Bytes(0xB8);
mb = bmp085Read2Bytes(0xBA);
mc = bmp085Read2Bytes(0xBC);
md = bmp085Read2Bytes(0xBE);
/*
printf("%Ld \n",ac1);
printf("%Ld \n",ac2);
printf("%Ld \n",ac3);
printf("%Lu \n",ac4);
printf("%Lu \n",ac5);
printf("%Lu \n",ac6);
printf("%Ld \n",b1);
printf("%Ld \n",b2);
printf("%Ld \n",mb);
printf("%Ld \n",mc);
printf("%Ld \n",md);
*/
}
/************************************************************************
*
* Purpose: Will read the 16-bit temperature value of BMP085 sensor.
* Passed: Void
* Returned: Long
* Note:
*
************************************************************************/
long bmp085ReadTemp(void)
{
i2c_start();
i2c_write(BMP085_W); // Write 0xEE
i2c_write(0xF4); // Write register address
i2c_write(0x2E); // Write register data for temp
i2c_stop();
delay_ms(10); // Max time is 4.5ms
return bmp085Read2Bytes(0xF6);
}
/************************************************************************
*
* Purpose: Will read the 16-bit pressure value from BMP085 sensor.
* Passed: Void
* Returned: Long
* Note:
*
************************************************************************/
unsigned long bmp085ReadPressure(void)
{
i2c_start();
i2c_write(BMP085_W); // Write 0xEE
i2c_write(0xF4); // Write register address
i2c_write(0x34 | (OSS << 6)); // Write register data for temp
i2c_stop();
delay_ms(OSS_conversion_time[OSS]); // Max time is 4.5ms
return bmp085Read3Bytes(0xF6);
}
/************************************************************************
*
* Purpose: Will find callibrated pressure + temperature
* Passed: Long *temperature, long *pressure, unsigned char readings
* Returned: Void
* Note:
*
************************************************************************/
// The bit-shift for possibly negative numbers.
// Note that divide has a higher precedence than
// bit shift, so this is not precisely the same.
void bmp085Convert(float long *temperature, float long *pressure)
{
unsigned long ut,up;
//float32 b5, b6, x3, b3, p, b4, b7;
signed long aux1,aux2,aux3,aux4;
float long c3,c4,c5,c6,bb1,mmc,mmd,x,x0,x1,x2,y,y0,y1,y2,p0,p1,p2,z,s,alpha,temp,pres;
ut = bmp085ReadTemp();
ut = bmp085ReadTemp();
up = bmp085ReadPressure();
up = bmp085ReadPressure();
//ut = 0x7B50;
//up = 0x883F;
//printf("%LX \n",ut);
//printf("%LX \n",up);
//but = ut; //Debug var
/*NEW CALCS*/
c3 = 160*pow(2,-15)*ac3;
c4 = pow(10,-3)*pow(2,-15)*ac4;
bb1 = 25600*pow(2,-30)*b1;
//printf("%e \n",c3);
//printf("%e \n",c4);
//printf("%e \n",bb1);
c5 = ac5*pow(2,-15)/160;
c6 = ac6;
mmc = (0.08)*mc;
mmd = md/160;
//printf("%e \n",c5);
//printf("%e \n",c6);
//printf("mmc\n");
//printf("%e \n",mmc);
//printf("%e \n",mmd);
x0 = ac1;
x1 = 160*pow(2,-13)*ac2;
x2 = 25600*pow(2,-25)*b2;
//printf("%e \n",x0);
//printf("%e \n",x1);
//printf("%e \n",x2);
y0 = c4*32768;
y1 = c4*c3;
y2 = c4*bb1;
//printf("%e \n",y0);
//printf("%e \n",y1);
//printf("%e \n",y2);
p0 = 3783/1600;
p1 = 1-7357*pow(2,-20);
p2 = 3038*100*pow(2,-36);
//printf("%e \n",p0);
//printf("%e \n",p1);
//printf("%e \n",p2);
/*Calculamos temperatura*/
alpha = c5*(ut-c6);
temp = alpha + (mmc/(alpha+mmd));
/*Calculamos presion*/
s = temp - 25;
x = x2*s*s+x1*s+x0;
y = y2*s*s+y1*s+y0;
z = (up-x)/y;
pres = p2*z*z+p1*z+p0;
*temperature = temp;
*pressure = pres;
/**/
/****************BEGIN*****CALC*****TEMP*********************/
/*
aux1 = ut-ac6;
aux2 = aux1*ac5;
x1 = aux2/32768;
//x1 = ((ut - ac6) * ac5 / pow(2,15));
aux3 = x1+md;
aux4 = mc/aux3;
x2 = aux4*2048;
//x2 = (mc * (pow(2,11))) / (x1 + md);
b5 = x1 + x2;
*temperature = ((b5 + 8) / 16);
/****************END*****CALC*****TEMP***********************/
/****************BEGIN*****CALC*****PRES*********************/
/*
up = up >> (8-OSS);
//bup = up; //Debug var
b6 = b5 - 4000;
aux1 = b6*b6;
aux2 = aux1/4096;
aux3 = aux2*b2;
x1 = aux3/2048;
//x1 = (b2 * (b6 * b6 / pow(2,12))) / pow(2,11);
aux1 = ac2*b6;
x2 = aux1/2048;
//x2 = ac2 * b6 / pow(2,11);
x3 = x1 + x2;
aux1 = ac1*4;
aux2 = aux1+x3;
shift = aux2;
aux3 = shift << OSS;
aux4 = aux3+2;
b3 = aux4/4;
//b3 = ((((ac1 * 4) + x3) << OSS) + 2) / 4;
aux1 = ac3*b6;
x1 = aux1/8192;
//x1 = ac3 * b6 / pow(2,13);
aux1 = b6*b6;
aux2 = aux1/4096;
aux3 = aux2*b1;
x2 = aux3/65536;
//x2 = (b1 * (b6 * b6 / pow(2,12))) / pow(2,16);
aux1 = x1+x2+2;
x3 = aux1/4;
//x3 = ((x1 + x2) + 2) / pow(2,2);
aux1 = x3+32768;
aux2 = ac4*aux1;
b4 = aux2/32768;
//b4 = (ac4 * (unsigned long) (x3 + 32768)) / pow(2,15);
aux1 = up-b3;
aux2 = 50000>>OSS;
b7 = aux1*aux2;
//b7 = ((unsigned long) up - b3) * (50000 >> OSS);
if (b7 < 0x80000000)
{
aux1 = b7*2;
p = aux1/b4;
}
else
{
aux1 = b7/b4;
p = aux1*2;
}
aux1 = p/256;
x1 = aux1*aux1;
//x1 = p / pow(2,8);
//x1 *= x1;
aux2 = x1*3038;
x1 = aux2/65536;
//x1 = (x1 * 3038) / pow(2,16);
aux1 = -7357*p;
x2 = aux1/65536;
//x2 = (-7357 * p) / pow(2,16);
aux1 = x1+x2+3791;
aux2 = aux1/16;
p = p+aux2;
*pressure = p;
/****************END*****CALC*****PRES***********************/
}#include <xc.h>
// Common I2C Routines
#define SDA_PIN PORTBbits.RB1 //
#define SCL_PIN PORTBbits.RB4 //
#define SDA_DIR TRISBbits.TRISB1
#define SCL_DIR TRISBbits.TRISB4
void i2c_high_sda(void)
{
// bring SDA to high impedance
SDA_DIR = 1;
DelayUs(5);
}
void i2c_low_sda(void)
{
SDA_PIN = 0;
SDA_DIR = 0; // output a hard logic zero
DelayUs(5);
}
void i2c_high_scl(void)
{
SCL_DIR = 1; // high impedance
DelayUs(5);
}
void i2c_low_scl(void)
{
SCL_PIN = 0;
SCL_DIR = 0;
DelayUs(5);
}
void i2c_read(unsigned short r_byte)
{
int n;
i2c_high_sda();
for (n=0; n<8; n++)
{
i2c_high_scl();
if (SDA_PIN)
{
r_byte = (r_byte << 1) | 0x01; // msbit first
}
else
{
r_byte = r_byte << 1;
}
i2c_low_scl();
}
return;
}
void i2c_write(signed char w_byte)
{
int m ;
for(m=0; m<8; m++)
{
if(w_byte&0x80)
{
i2c_high_sda();
}
else
{
i2c_low_sda();
}
i2c_high_scl();
i2c_low_scl();
w_byte = w_byte << 1;
}
i2c_high_sda();
}
void i2c_nack(void)
{
i2c_high_sda(); // data at one
i2c_high_scl(); // clock pulse
i2c_low_scl();
}
void i2c_ack(void)
{
i2c_low_sda(); // bring data low and clock
i2c_high_scl();
i2c_low_scl();
i2c_high_sda();
}
void i2c_start(void)
{
i2c_low_scl();
i2c_high_sda();
i2c_high_scl(); // bring SDA low while SCL is high
i2c_low_sda();
i2c_low_scl();
}
void i2c_stop(void)
{
i2c_low_scl();
i2c_low_sda();
i2c_high_scl();
i2c_high_sda(); // bring SDA high while SCL is high
// idle is SDA high and SCL high
}
void i2c_restart(void)
{
i2c_low_scl(); /* ensure clock is low */
i2c_high_scl(); /* ensure data is high */
SCL_DIR = 1; /* clock pulse high */
i2c_low_sda(); /* the high->low transition */
return;
}
¿Y funciona, o no?
Insisto en que está mal definida la función i2c_read();
unsigned short i2c_read()
{
unsigned short r_byte;
int n;
i2c_high_sda();
for (n=0; n<8; n++)
{
i2c_high_scl();
if (SDA_PIN)
{
r_byte = (r_byte << 1) | 0x01; // msbit first
}
else
{
r_byte = r_byte << 1;
}
i2c_low_scl();
}
return r_byte;
}Yo probaría las rutinas con una memoria tipo 24c04. Una vez que la hagas funcionar con dicha memoria, ya avanzar hacia el manejo del sensor.
Hice unas rutinas i2c por soft para hitech hace tiempo. Ahora comencé todo de cero e hice las rutinas en xc8 (versión 1.12). Por el momento las estoy testeando en ISIS con la herramienta I2C DEUGGER y parecen funcionar bien.
Ramiro, una consulta, pudiste medir presion?
no me cierra esta parte del código:
if(OSS) {
return bmp085ReadThreeBytes(0xF6);
} else {
return ((long) bmp085ReadShort(0xF6)) << 8;
}
eso está en bmp085ReadPressure
me parece que no se condice con las formulas del datasheet, pero a lo mejor estoy malinterpretando algo. vos lo probaste?
Saludos!
Ramiro, una consulta, pudiste medir presion?
no me cierra esta parte del código:
if(OSS) {
return bmp085ReadThreeBytes(0xF6);
} else {
return ((long) bmp085ReadShort(0xF6)) << 8;
}
eso está en bmp085ReadPressure
me parece que no se condice con las formulas del datasheet, pero a lo mejor estoy malinterpretando algo. vos lo probaste?
Saludos!
Ramiro, una consulta, pudiste medir presion?
no me cierra esta parte del código:
if(OSS) {
return bmp085ReadThreeBytes(0xF6);
} else {
return ((long) bmp085ReadShort(0xF6)) << 8;
}
eso está en bmp085ReadPressure
me parece que no se condice con las formulas del datasheet, pero a lo mejor estoy malinterpretando algo. vos lo probaste?
Saludos!
Fijate que este codigo fueron mis primeras pruebas con el sensor , con esto no pude leer presion , solo temperatura , pero con el codigo que esta escrito enel curso de xc8 , me anda perfecto , incluso estan los videos en mi canal de youtube ...en este codigo , uso una lib por soft de i2c , porque el pic que estaba usando no la tenia , en el otro codigo uso la lib de c18 de plib ....
te compila bien ??? deberia andar , ojo no este codigo , el otro si
Saludos
Ramiro, como andas!
Te comento que venía haciendo tal como lo sugeris, primro hice la lectura de los datos de calibracion. Como trabajo con una placa con un micro ARM (no con PIC) me costo bastante encontrar una buena librería para I2C y despues empezar a transformar el código. Antes de ayer a la madrugada dejé funcionando la lectura de los datos de calibracion.
Anoche me puse con la medicion de temperatura y presion.
La temperatura salio fácil, las formulas copie tal cual las que vos pusiste.
Pero con la presion tenia una duda ya que la parte del codigo que pegue arriba no coincide con la hoja de datos...
Despues, segui renegando y mirando más el código y encontre lo que faltaba. En donde calculas la presion real, haces el deslpazamiento de los bits en (OSS-8) cosa que no estaba en la parte del código que te copie.... en fin, tu código esta perfecto y a mí ya me quedó funcionando bien. Lo probe anoche y media 1011 hPa y 21°C. Coincidía bastante con los datos del SMN de Rosario....
Bueno, ahora pase a los otros sensores, en este momento estoy trabajando con el compas electrónico o magnetómetro...
Saludos y gracias!!!