Diff: BMP085/BMP085.cpp

Revision:

1:e08a4f517989

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/BMP085/BMP085.cpp	Tue Aug 27 09:38:49 2013 +0000
@@ -0,0 +1,129 @@
+#include "BMP085.h"
+
+BMP085::BMP085(){}
+
+void BMP085::write(char reg,char data){
+    
+    char tx[2]={reg,data};
+
+    I2C0.blockwrite((BMP_ADDRESS << 1)&0xFE, tx, 2);
+
+ }
+
+int16 BMP085::read (char reg){
+
+    char tx = reg;
+    char rx[2];
+
+    I2C0.blockwrite((BMP_ADDRESS << 1)&0xFE, &tx, 1);
+
+    I2C0.blockread((BMP_ADDRESS << 1)|0x01, rx, 2);
+
+    int16 output = ((int16) rx[0] << 8) | ((int16) rx[1]);
+    return output;
+}
+
+uint8 BMP085::readInt (char reg){
+
+    char tx = reg;
+    char rx;
+
+    I2C0.blockwrite((BMP_ADDRESS << 1)&0xFE, &tx, 1);
+
+    I2C0.blockread((BMP_ADDRESS << 1)|0x01, &rx, 1);
+    
+    return rx;
+}
+
+// Get Calibration Values
+void BMP085::Calibrate(void){
+
+  AC1 = read(0xAA);
+  AC2 = read(0xAC);
+  AC3 = read(0xAE);
+  AC4 = read(0xB0);
+  AC5 = read(0xB2);
+  AC6 = read(0xB4);
+  B1  = read(0xB6);
+  B2  = read(0xB8);
+  MB  = read(0xBA);
+  MC  = read(0xBC);
+  MD  = read(0xBE);
+ 
+}
+
+//Uncompensated temperature takes 4.5ms to read, so we'll just send a read flag and read the data the next cycle since our control loop repeats every 5 ms 
+
+void BMP085::readUT_Flag(void){
+
+  write(0xF4,0x2E);
+}
+
+// reading uncompensated Pressure depends on our resolution setting, we'll select ultra high resolution setting so the delay will be 25.5ms (5 iterations);
+
+void BMP085::readUP_Flag(void){
+
+  write(0xF4,(0x34 + (OSS<<6)));
+}
+
+uint16 BMP085::readUT(void){
+  
+  uint16 ut = (uint16)read(0xF6);
+  
+  return ut;
+  
+}
+uint32 BMP085::readUP(void){
+  
+  uint32 up = (((uint32) readInt(0xF6) << 16) | ((uint32) readInt(0xF7) << 8) | (uint32) readInt(0xF8)) >> (8-OSS);
+  
+  return up;
+}
+
+int16 BMP085::read_Temperature(void){
+
+ int32 X1,X2;
+ 
+ X1 = (((int32)readUT() - (int32)AC6)*(int32)AC5) >> 15;
+ X2 = ((int32)MC << 11)/(X1 + MD);
+ 
+ B5 = X1+X2;
+ 
+ return ((B5 + 8)>>4); 
+}
+
+int32 BMP085::read_Pressure(void){
+  
+  int32 X1, X2, X3, B3, B6, p;
+  uint32 B4, B7;
+  
+  B6 = B5 - 4000;
+  // Calculate B3
+  X1 = (B2 * (B6 * B6)>>12)>>11;
+  X2 = (AC2 * B6)>>11;
+  X3 = X1 + X2;
+  B3 = (((((int32)AC1)*4 + X3)<<OSS) + 2)>>2;
+  
+  // Calculate B4
+  X1 = (AC3 * B6)>>13;
+  X2 = (B1 * ((B6 * B6)>>12))>>16;
+  X3 = ((X1 + X2) + 2)>>2;
+  B4 = (AC4 * (uint32)(X3 + 32768))>>15;
+  
+  B7 = ((uint32)(readUP() - B3) * (50000>>OSS));
+  
+  if (B7 < (uint32)0x80000000)
+  {
+    p = (B7<<1)/B4;
+    }
+  else{
+    p = (B7/B4)<<1;
+    }
+    
+  X1 = (p>>8) * (p>>8);
+  X1 = (X1 * 3038)>>16;
+  X2 = (-7357 * p)>>16;
+  p += (X1 + X2 + 3791)>>4;
+  
+  return p;
+}