BMP085 Barometric Pressure Sensor Breakout - Revision history

Admin: /* Example code */

2012-12-10T01:51:51Z

Example code

← Older revision		Revision as of 01:51, 10 December 2012
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	For Arduino 1.0+		For Arduino 1.0+

	#include <Wire.h>		#include <Wire.h>
	#define BMP085_ADDRESS 0x77 // I2C address of BMP085		#define BMP085_ADDRESS 0x77 // I2C address of BMP085
	const unsigned char OSS = 0; // Oversampling Setting		const unsigned char OSS = 0; // Oversampling Setting
	// Calibration values		// Calibration values
	int ac1;		int ac1;
	int ac2;		int ac2;
	int ac3;		int ac3;
	unsigned int ac4;		unsigned int ac4;
	unsigned int ac5;		unsigned int ac5;
	unsigned int ac6;		unsigned int ac6;
	int b1;		int b1;
	int b2;		int b2;
	int mb;		int mb;
	int mc;		int mc;
	int md;		int md;
	// b5 is calculated in bmp085GetTemperature(...), this variable is also used in bmp085GetPressure(...)		// b5 is calculated in bmp085GetTemperature(...), this variable is also used in bmp085GetPressure(...)
	// so ...Temperature(...) must be called before ...Pressure(...).		// so ...Temperature(...) must be called before ...Pressure(...).
	long b5;		long b5;
	short temperature;		short temperature;
	long pressure;		long pressure;
	void setup()		void setup()
	{		{
	Serial.begin(9600);		Serial.begin(9600);
	Wire.begin();		Wire.begin();
	bmp085Calibration();		bmp085Calibration();
	}		}
	void loop()		void loop()
	{		{
	temperature = bmp085GetTemperature(bmp085ReadUT());		temperature = bmp085GetTemperature(bmp085ReadUT());
	pressure = bmp085GetPressure(bmp085ReadUP());		pressure = bmp085GetPressure(bmp085ReadUP());
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	Serial.println();		Serial.println();
	delay(1000);		delay(1000);
	}		}
	// Stores all of the bmp085's calibration values into global variables		// Stores all of the bmp085's calibration values into global variables
	// Calibration values are required to calculate temp and pressure		// Calibration values are required to calculate temp and pressure
	// This function should be called at the beginning of the program		// This function should be called at the beginning of the program
	void bmp085Calibration()		void bmp085Calibration()
	{		{
	ac1 = bmp085ReadInt(0xAA);		ac1 = bmp085ReadInt(0xAA);
	ac2 = bmp085ReadInt(0xAC);		ac2 = bmp085ReadInt(0xAC);
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	mc = bmp085ReadInt(0xBC);		mc = bmp085ReadInt(0xBC);
	md = bmp085ReadInt(0xBE);		md = bmp085ReadInt(0xBE);
	}		}
	// Calculate temperature given ut.		// Calculate temperature given ut.
	// Value returned will be in units of 0.1 deg C		// Value returned will be in units of 0.1 deg C
	short bmp085GetTemperature(unsigned int ut)		short bmp085GetTemperature(unsigned int ut)
	{		{
	long x1, x2;		long x1, x2;
	x1 = (((long)ut - (long)ac6)*(long)ac5) >> 15;		x1 = (((long)ut - (long)ac6)*(long)ac5) >> 15;
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	b5 = x1 + x2;		b5 = x1 + x2;
	return ((b5 + 8)>>4);		return ((b5 + 8)>>4);
	}		}
	// Calculate pressure given up		// Calculate pressure given up
	// calibration values must be known		// calibration values must be known
	// b5 is also required so bmp085GetTemperature(...) must be called first.		// b5 is also required so bmp085GetTemperature(...) must be called first.
	// Value returned will be pressure in units of Pa.		// Value returned will be pressure in units of Pa.
	long bmp085GetPressure(unsigned long up)		long bmp085GetPressure(unsigned long up)
	{		{
	long x1, x2, x3, b3, b6, p;		long x1, x2, x3, b3, b6, p;
	unsigned long b4, b7;		unsigned long b4, b7;
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	p += (x1 + x2 + 3791)>>4;		p += (x1 + x2 + 3791)>>4;
	return p;		return p;
	}		}
	// Read 1 byte from the BMP085 at 'address'		// Read 1 byte from the BMP085 at 'address'
	char bmp085Read(unsigned char address)		char bmp085Read(unsigned char address)
	{		{
	unsigned char data;		unsigned char data;
	Wire.beginTransmission(BMP085_ADDRESS);		Wire.beginTransmission(BMP085_ADDRESS);
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	while(!Wire.available());		while(!Wire.available());
	return Wire.read();		return Wire.read();
	}		}
	// Read 2 bytes from the BMP085		// Read 2 bytes from the BMP085
	// First byte will be from 'address'		// First byte will be from 'address'
	// Second byte will be from 'address'+1		// Second byte will be from 'address'+1
	int bmp085ReadInt(unsigned char address)		int bmp085ReadInt(unsigned char address)
	{		{
	unsigned char msb, lsb;		unsigned char msb, lsb;
	Wire.beginTransmission(BMP085_ADDRESS);		Wire.beginTransmission(BMP085_ADDRESS);
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	lsb = Wire.read();		lsb = Wire.read();
	return (int) msb<<8 \| lsb;		return (int) msb<<8 \| lsb;
	}		}
	// Read the uncompensated temperature value		// Read the uncompensated temperature value
	unsigned int bmp085ReadUT()		unsigned int bmp085ReadUT()
	{		{
	unsigned int ut;		unsigned int ut;
	// Write 0x2E into Register 0xF4		// Write 0x2E into Register 0xF4
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	ut = bmp085ReadInt(0xF6);		ut = bmp085ReadInt(0xF6);
	return ut;		return ut;
	}		}
	// Read the uncompensated pressure value		// Read the uncompensated pressure value
	unsigned long bmp085ReadUP()		unsigned long bmp085ReadUP()
	{		{
	unsigned char msb, lsb, xlsb;		unsigned char msb, lsb, xlsb;
	unsigned long up = 0;		unsigned long up = 0;
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	up = (((unsigned long) msb << 16) \| ((unsigned long) lsb << 8) \| (unsigned long) xlsb) >> (8-OSS);		up = (((unsigned long) msb << 16) \| ((unsigned long) lsb << 8) \| (unsigned long) xlsb) >> (8-OSS);
	return up;		return up;
	}		}

	==How to buy==		==How to buy==
	Click here to buy [http://www.geeetech.com/bmp085-breakoutbarometric-pressure-sensor-p-530.html BMP085 Barometric Pressure Sensor Breakout]		Click here to buy [http://www.geeetech.com/bmp085-breakoutbarometric-pressure-sensor-p-530.html BMP085 Barometric Pressure Sensor Breakout]

Admin at 01:50, 10 December 2012

2012-12-10T01:50:03Z

← Older revision		Revision as of 01:50, 10 December 2012
Line 26:		Line 26:

	==Example code==		==Example code==
	#include <Wire.h>		For Arduino 1.0+

			#include <Wire.h>
	#define BMP085_ADDRESS 0x77 // I2C address of BMP085		#define BMP085_ADDRESS 0x77 // I2C address of BMP085
	const unsigned char OSS = 0; // Oversampling Setting		const unsigned char OSS = 0; // Oversampling Setting

Admin: /* Example code */

2012-12-10T01:49:22Z

Example code

Show changes

Admin at 09:07, 9 August 2012

2012-08-09T09:07:58Z

← Older revision		Revision as of 09:07, 9 August 2012
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	*Temperature measurement included		*Temperature measurement included
	*Ultra-flat, small footprint		*Ultra-flat, small footprint

			==Document==
			[http://dlnmh9ip6v2uc.cloudfront.net/datasheets/Sensors/Pressure/BST-BMP085-DS000-06.pdf BMP085 Datasheet]

	==Usage==		==Usage==

Admin: /* Example code */

2012-08-07T01:22:39Z

Example code

Show changes

Admin: /* Example code */

2012-06-29T01:14:31Z

Example code

← Older revision		Revision as of 01:14, 29 June 2012
Line 23:		Line 23:

	==Example code==		==Example code==
	[http://www.geeetech.com/Documents/~~BMP085%20Example%20Code~~.zip BMP085 arduino example code]		[http://www.geeetech.com/Documents/BMP085_Arduino_Example.zip BMP085 arduino example code]

	==How to buy==		==How to buy==
	Click here to buy [http://www.geeetech.com/bmp085-breakoutbarometric-pressure-sensor-p-530.html BMP085 Barometric Pressure Sensor Breakout]		Click here to buy [http://www.geeetech.com/bmp085-breakoutbarometric-pressure-sensor-p-530.html BMP085 Barometric Pressure Sensor Breakout]

Admin: /* Usage */

2012-05-24T03:38:40Z

Usage

← Older revision		Revision as of 03:38, 24 May 2012
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	[[File:BMP085-3.jpg\|600px]]		[[File:BMP085-3.jpg\|600px]]

	[[File:~~BMP table~~.jpg]]		[[File:BMPtable.jpg]]

	==Example code==		==Example code==

Admin: /* Usage */

2012-05-24T03:37:01Z

Usage

← Older revision		Revision as of 03:37, 24 May 2012
Line 18:		Line 18:
	Here is the guide illustrates how to connect an Arduino to the BMP085 breakout board.		Here is the guide illustrates how to connect an Arduino to the BMP085 breakout board.

	[[File:BMP085-3.jpg\|~~700px~~]]		[[File:BMP085-3.jpg\|600px]]

	[[File:BMP table.jpg]]		[[File:BMP table.jpg]]

Admin: /* Usage */

2012-05-24T03:36:50Z

Usage

← Older revision		Revision as of 03:36, 24 May 2012
Line 19:		Line 19:

	[[File:BMP085-3.jpg\|700px]]		[[File:BMP085-3.jpg\|700px]]

	[[File:BMP table.jpg]]		[[File:BMP table.jpg]]

Admin at 03:36, 24 May 2012

2012-05-24T03:36:41Z

← Older revision		Revision as of 03:36, 24 May 2012
Line 18:		Line 18:
	Here is the guide illustrates how to connect an Arduino to the BMP085 breakout board.		Here is the guide illustrates how to connect an Arduino to the BMP085 breakout board.

	[[File:BMP085-4.jpg\|700px]]		[[File:BMP085-3.jpg\|700px]]
			[[File:BMP table.jpg]]

	==Example code==		==Example code==