Jörg Weber
Program to test the pressure sensor BMP183 in spi mode on the Adafruit breakout board
Revision 1:03d398b1eb4b, committed 2016-06-21
- Comitter:
- Cirrus01
- Date:
- Tue Jun 21 10:27:09 2016 +0000
- Parent:
- 0:116f8291dc01
- Commit message:
- Just imported BMP183 as library and added text
Changed in this revision
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/BMP183.lib Tue Jun 21 10:27:09 2016 +0000 @@ -0,0 +1,1 @@ +http://mbed.org/users/Cirrus01/code/BMP183/#3750c8d10767
--- a/BMP183/BMP183.cpp Sat Sep 12 12:09:35 2015 +0000
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,119 +0,0 @@
-
-#include "BMP183.h"
-
-BMP183::BMP183(PinName MOSI, PinName MISO, PinName SCLK, PinName CS): spi(MOSI, MISO, SCLK), cs(CS) {
- ChipDeselect();
- spi.format(8, 3);
- spi.frequency(5e6);
-}
-
-uint8_t BMP183::getID(void)
-{
- char response[1];
- readRegister(BMP183_REGISTER_CHIPID, response, 1);
- return response[0];
-}
-
-void BMP183::getCalibrationData(void)
-{
- char buffer[22]; // 8-Bit pieces of axis data
- readRegister(BMP183_REGISTER_CAL_AC1, buffer, 22); // read all calibration registers in one time 22 Byte = 176 Bit
-
- AC1 = (short) (buffer[0] << 8 | buffer[1]); // join 8-Bit pieces to 16-bit short integers
- AC2 = (short) (buffer[2] << 8 | buffer[3]);
- AC3 = (short) (buffer[4] << 8 | buffer[5]);
- AC4 = (unsigned short) (buffer[6] << 8 | buffer[7]); // unsigned !!
- AC5 = (unsigned short) (buffer[8] << 8 | buffer[9]);
- AC6 = (unsigned short) (buffer[10] << 8 | buffer[11]);
- B1 = (short) (buffer[12] << 8 | buffer[13]);
- B2 = (short) (buffer[14] << 8 | buffer[15]);
- MB = (short) (buffer[16] << 8 | buffer[17]);
- MC = (short) (buffer[18] << 8 | buffer[19]);
- MD = (short) (buffer[20] << 8 | buffer[21]);
-
-
- oss = 0; // set Oversampling of Sensor
-}
-
-void BMP183::read(void)
-{
- unsigned short Uncompensated_Temperature;
- long P, Uncompensated_Pressure, X1, X2, X3, B3, B5, B6;
- unsigned long B4, B7;
-
- // read uncompensated Temperature
- writeRegister(BMP183_REGISTER_CONTROL, BMP183_REGISTER_READTEMPCMD);// say the sensor we want to read the temperature
- wait(0.005); // Wait at least 4.5ms (written in data sheet)
- char buffer[3]; // TODO: nur 2 wenn unten nicht gebraucht // read 16-Bit Temperature (2 registers)
- readRegister(BMP183_REGISTER_TEMPDATA, buffer, 2);
- Uncompensated_Temperature = buffer[0] << 8 | buffer[1]; // join 8-Bit pieces to 16-bit short integer
-
- // calculate real Temperature
- X1 = ((Uncompensated_Temperature - AC6) * AC5) >> 15;
- X2 = (MC << 11) / (X1 + MD);
- B5 = X1 + X2; // - ((33 << 4) - 8);
- Temperature = (float)((B5 + 8) >> 4)/10.0; // we want temperature in degree with digit after comma
-
- // read uncompensated Pressure
- writeRegister(BMP183_REGISTER_CONTROL, BMP183_REGISTER_READPRESSURECMD + (oss << 6));// say the sensor we want to read the pressure
- wait(0.005); // Wait at least 4.5ms (written in data sheet) TODO: oss fest, times vary and calculation of B3
- readRegister(BMP183_REGISTER_PRESSUREDATA, buffer, 3); // read 24-Bit Pressure (3 registers)
- Uncompensated_Pressure = (unsigned int) (buffer[0] << 16 | buffer[1] << 8 | buffer[0]) >> (8 - oss); // join 8-Bit pieces to 24-bit integer
-
- // calculate real Pressure
- B6 = B5 - 4000; // B5 is updated by real temperature above
- X1 = (B2 * ( (B6 * B6) >> 12 )) >> 11;
- X2 = (AC2 * B6) >> 11;
- X3 = X1 + X2;
- B3 = (((AC1 * 4 + X3) << oss) + 2) >> 2;
-
- 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)Uncompensated_Pressure - B3) * (50000 >> oss);
-
- if (B7 < 0x80000000)
- P = (B7 * 2) / B4;
- else
- P = (B7 / B4) * 2;
-
- X1 = (P >> 8) * (P >> 8);
- X1 = (X1 * 3038) >> 16;
- X2 = (-7357 * P) >> 16;
- P = P + ((X1 + X2 + 3791) >> 4);
- Pressure = (float)P / 100.0;
-
- // calculate height out of the pressure
- Altitude = 44330 * (1.0 - pow((Pressure / 1013.25), 1/5.25588));
-}
-
-//////////////////////////////////////////////////////////////////////////
-/// SPI Functions
-//////////////////////////////////////////////////////////////////////////
-
-void BMP183::readRegister(uint8_t reg, char *buffer, int length) {
- ChipSelect();
- spi.write(reg | 0x80); // send the register address we want to read and the read flag
- for(int i=0; i<length; i++) // get data
- buffer[i] = spi.write(0x00);
- ChipDeselect();
-}
-
-void BMP183::writeRegister(uint8_t reg, char *buffer, int length) {
- ChipSelect();
- spi.write(reg & ~0x80); // send the register address we want to write and the write flag
- for(int i=0; i<length; i++) // put data
- spi.write(buffer[i]);
- ChipDeselect();
-}
-
-void BMP183::writeRegister(uint8_t reg, int data) {
- ChipSelect();
- spi.write(reg & ~0x80); // send the register address we want to write and the write flag
- spi.write(data); // put data
- ChipDeselect();
-}
-void BMP183::ChipSelect() { cs = 0; } // set Cable Select pin low to start SPI transaction
-void BMP183::ChipDeselect() { cs = 1; } // set Cable Select pin high to stop SPI transaction
--- a/BMP183/BMP183.h Sat Sep 12 12:09:35 2015 +0000
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,70 +0,0 @@
-#ifndef BMP183_H
-#define BMP183_H
-
-#include "mbed.h"
-
-/*=========================================================================
- REGISTERS
- -----------------------------------------------------------------------*/
-
-#define BMP183_REGISTER_CAL_AC1 0xAA // R Calibration data (16 bits)
-#define BMP183_REGISTER_CAL_AC2 0xAC // R Calibration data (16 bits)
-#define BMP183_REGISTER_CAL_AC3 0xAE // R Calibration data (16 bits)
-#define BMP183_REGISTER_CAL_AC4 0xB0 // R Calibration data (16 bits)
-#define BMP183_REGISTER_CAL_AC5 0xB2 // R Calibration data (16 bits)
-#define BMP183_REGISTER_CAL_AC6 0xB4 // R Calibration data (16 bits)
-#define BMP183_REGISTER_CAL_B1 0xB6 // R Calibration data (16 bits)
-#define BMP183_REGISTER_CAL_B2 0xB8 // R Calibration data (16 bits)
-#define BMP183_REGISTER_CAL_MB 0xBA // R Calibration data (16 bits)
-#define BMP183_REGISTER_CAL_MC 0xBC // R Calibration data (16 bits)
-#define BMP183_REGISTER_CAL_MD 0xBE // R Calibration data (16 bits)
-#define BMP183_REGISTER_CHIPID 0xD0
-#define BMP183_REGISTER_VERSION 0xD1
-#define BMP183_REGISTER_SOFTRESET 0xE0
-#define BMP183_REGISTER_CONTROL 0xF4
-#define BMP183_REGISTER_TEMPDATA 0xF6
-#define BMP183_REGISTER_PRESSUREDATA 0xF6
-#define BMP183_REGISTER_READTEMPCMD 0x2E
-#define BMP183_REGISTER_READPRESSURECMD 0x34
-
-/*=========================================================================*/
-
-/*=========================================================================
- MODE SETTINGS
- -----------------------------------------------------------------------*/
-
-#define BMP183_MODE_ULTRALOWPOWER 0
-#define BMP183_MODE_STANDARD 1
-#define BMP183_MODE_HIGHRES 2
-#define BMP183_MODE_ULTRAHIGHRES 3
-
-/*=========================================================================*/
-
-class BMP183
-{
-public:
- BMP183(PinName MOSI, PinName MISO, PinName SCLK, PinName CS);
-
- uint8_t getID(void);
- void getCalibrationData(void);
- void read(void);
- float Temperature, Pressure, Altitude;
-
-private:
- SPI spi;
- DigitalOut cs;
-
- short AC1, AC2, AC3, B1, B2, MB, MC, MD;
- unsigned short AC4, AC5, AC6;
- short oss;
-
- void readRegister(uint8_t reg, char *buffer, int length);
- void writeRegister(uint8_t reg, int data);
- void writeRegister(uint8_t reg, char *buffer, int length);
-
- void ChipSelect(void);
- void ChipDeselect(void);
-};
-
-
-#endif // BMP183_H
\ No newline at end of file
--- a/main.cpp Sat Sep 12 12:09:35 2015 +0000
+++ b/main.cpp Tue Jun 21 10:27:09 2016 +0000
@@ -1,3 +1,4 @@
+//Imported BMP183 as library
#include "mbed.h"
#include "BMP183.h"
@@ -42,6 +43,9 @@
t.reset();
baro.read();
time = t.read_ms();
- serial.printf("Time: %i - Temp.: %f - Pres.: %f - Alt.: %f\n", time, baro.Temperature, baro.Pressure, baro.Altitude);
+ serial.printf("Time: %i\n", time);
+ serial.printf("Temp.: %f\n", baro.Temperature);
+ serial.printf("Pres.: %f\n", baro.Pressure);
+ serial.printf("Alt.: %f\n", baro.Altitude);
}
}