Revision 0:2ae3dabe45e8, committed 2013-10-02

Comitter:

mr63

Date:

Wed Oct 02 14:02:29 2013 +0000

Commit message:

This is a class for the BMP085 Pressure Temperature sensor from Sparkfun. I believe that the sensor I have does not work, so if this doesn't work let me know.

Changed in this revision

diff -r 000000000000 -r 2ae3dabe45e8 BMP085.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/BMP085.cpp	Wed Oct 02 14:02:29 2013 +0000
@@ -0,0 +1,144 @@
+#include "BMP085.h"
+
+I2C i2c(p28, p27);
+
+int _SlaveA;                    //local variable that holds the Slave Address
+
+int  AC1,AC2,AC3,B1,B2,MB,MC,MD;
+int AC4,AC5,AC6;
+long B5;
+
+
+char _SensorData[8] ={100,100,100};  //Char array that holds the current Altitude and Temperature dat
+
+
+
+//BMP085 Class Constructor
+BMP085::BMP085 (int SlaveAddress, PinName sda, PinName scl, PinName EOC) : _i2c(sda,scl), _eoc(EOC)
+{
+		_eoc.mode(PullUp);
+		_SlaveA = SlaveAddress;
+		
+}
+
+
+int BMP085::Write_Register (char regnum, char data)   //Used for writing data to the BMP085 Registers
+{
+		char Write_Data[2];
+		Write_Data[0] = regnum;
+		Write_Data[1] = data;
+		return(_i2c.write(_SlaveA, Write_Data, 2));
+}
+
+int BMP085::Read_Register (char regnum, int numbofbytes)   //
+{
+		char Write_Data[1];    
+	  Write_Data[0] = regnum;
+	  _i2c.write(_SlaveA, Write_Data, 1,true);
+	  _i2c.read(_SlaveA, _SensorData, numbofbytes);	
+		return(1);
+
+}
+
+int BMP085::Read_ConversionValue(unsigned char type)     //
+{
+      Write_Register(0xF4,type);
+	    for(int t=0; t<5000;t++);
+			while(!_eoc);
+			Read_Register(0xF6,2);
+			return (((int)_SensorData[0]*256+_SensorData[1]));		
+}
+
+void BMP085::GetCalibrationData()
+{
+			
+			AC1=(int)return16bit(0xAA);
+				
+			AC2=(int)return16bit(0xAC);
+			
+			AC3=(int)return16bit(0xAE);
+			
+			AC4=return16bit(0xB0);
+			
+		  AC5=return16bit(0xB2);
+
+			AC6=return16bit(0xB4);
+
+			B1=(int)return16bit(0xB6);
+
+			B2=(int)return16bit(0xB8);
+			
+			MB=(int)return16bit(0xBA);
+			
+			MC=(int)return16bit(0xBC);
+			
+			MD=(int)return16bit(0xBE);		
+}
+
+int BMP085::return16bit(int Reg)     //Read Data Register from MPL3115A2 Sensor
+{  
+	  Read_Register(Reg,2);
+	  return ((int)(_SensorData[0]*256+_SensorData[1]));
+}
+
+
+int BMP085::calculate_tempc()
+{
+	long X1;
+	long X2;
+	int tempin;
+	tempin=Read_ConversionValue(Temp);
+	if(tempin>0)
+	{
+	X1=(long)((long)tempin-AC6)*AC5/32768;
+	X2=(long)MC*2048/(X1+MD);
+	B5=X1+X2;
+	return((B5+8)/16);
+	//return(tempin);	
+	}
+	return (0);
+}
+
+int BMP085::calculate_pressure()
+{
+	long B6, X1,X2,X3,B3,P;
+  unsigned long B4,B7;
+	int presin;
+	presin=Read_ConversionValue(Pressure);
+	
+	if(presin>0)
+	{	
+		B6=B5-4000;
+		X1=(B2*(B6*B6/4096))/2048;
+		X2=AC2*B6/2048;
+		X3=X1+X2;
+		B3=(AC1*4+X3)/4;
+		X1=(long)AC3*B6/8192;
+		X2=((long)B1*(B6*B6/4096))/65536;
+		X3=((X1+X2)+2)/4;
+		B4=(long)AC4*(X3+32768)/32768;
+		B7=((long)presin-B3)*(50000);
+		if(B7<0X80000000)
+		{
+				P=(B7*2)/B4;
+		}
+		else
+		{
+			P = (B7/B4)*2;
+		}
+		X1 = (P/256)*(P/256);
+		X1 = (X1*3038)/65536;
+		X2 = (-7357*P)/65536;
+		P=P + (X1 + X2 + 3792)/16;
+		P=P/1000;
+		return ((int)P);
+ }
+ return(0);
+}
+
+
+
+
+
+
+

diff -r 000000000000 -r 2ae3dabe45e8 BMP085.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/BMP085.h	Wed Oct 02 14:02:29 2013 +0000
@@ -0,0 +1,25 @@
+#include "mbed.h"
+
+#define Temp 0x2E
+#define Pressure 0x34
+
+
+class BMP085 {
+public:
+	
+    BMP085(int SlaveAddress, PinName sda, PinName scl, PinName EOC);
+
+		int Read_ConversionValue(unsigned char type);
+		void GetCalibrationData();
+		int calculate_tempc();
+		int calculate_pressure();
+
+private:
+    I2C _i2c;   
+    DigitalIn _eoc;
+		int return16bit(int Reg);
+		int Write_Register (char regnum, char data); 
+		int Read_Register (char regnum, int numbofbytes);  
+};
+
+

diff -r 000000000000 -r 2ae3dabe45e8 main.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Wed Oct 02 14:02:29 2013 +0000
@@ -0,0 +1,19 @@
+#include "mbed.h"
+#include "BMP085.h"
+const int SlaveAddressI2C = 0xEE;  //This is the slave address of the device
+Serial pc(USBTX, USBRX);
+BMP085 Sensor(SlaveAddressI2C, p28, p27, p21);
+
+int main() {
+
+		Sensor.GetCalibrationData();
+
+	while(1)
+	{
+
+ 			pc.printf("Temp=%d deg C\n\r",Sensor.calculate_tempc());	
+ 			pc.printf("Pressure=%dkPa\n\r",Sensor.calculate_pressure());
+
+ 		  wait(1);
+	}
+}