分享 GY68BMP180 氣壓模塊 Arduino 的例程序
- //Arduino 1.0+ Only
- //Arduino 1.0+ Only
- /*Based largely on code by Jim Lindblom
- Get pressure, altitude, and temperature from the BMP085.
- Serial.print it out at 9600 baud to serial monitor.
- */
- #include <Wire.h>
- #define BMP085_ADDRESS 0x77 // I2C address of BMP085
- const unsigned char OSS = 0; // Oversampling Setting
- // Calibration values
- int ac1;
- int ac2;
- int ac3;
- unsigned int ac4;
- unsigned int ac5;
- unsigned int ac6;
- int b1;
- int b2;
- int mb;
- int mc;
- int md;
- // b5 is calculated in bmp085GetTemperature(...), this variable is also used in bmp085GetPressure(...)
- // so ...Temperature(...) must be called before ...Pressure(...).
- long b5;
- void setup(){
- Serial.begin(9600);
- Wire.begin();
- bmp085Calibration();
- }
- void loop()
- {
- float temperature = bmp085GetTemperature(bmp085ReadUT()); //MUST be called first
- float pressure = bmp085GetPressure(bmp085ReadUP());
- float atm = pressure / 101325; // "standard atmosphere"
- float altitude = calcAltitude(pressure); //Uncompensated caculation - in Meters
- Serial.print("Temperature: ");
- Serial.print(temperature, 2); //display 2 decimal places
- Serial.println("deg C");
- Serial.print("Pressure: ");
- Serial.print(pressure, 0); //whole number only.
- Serial.println(" Pa");
- Serial.print("Standard Atmosphere: ");
- Serial.println(atm, 4); //display 4 decimal places
- Serial.print("Altitude: ");
- Serial.print(altitude, 2); //display 2 decimal places
- Serial.println(" M");
- Serial.println();//line break
- delay(1000); //wait a second and get values again.
- }
- // Stores all of the bmp085's calibration values into global variables
- // Calibration values are required to calculate temp and pressure
- // This function should be called at the beginning of the program
- void bmp085Calibration()
- {
- ac1 = bmp085ReadInt(0xAA);
- ac2 = bmp085ReadInt(0xAC);
- ac3 = bmp085ReadInt(0xAE);
- ac4 = bmp085ReadInt(0xB0);
- ac5 = bmp085ReadInt(0xB2);
- ac6 = bmp085ReadInt(0xB4);
- b1 = bmp085ReadInt(0xB6);
- b2 = bmp085ReadInt(0xB8);
- mb = bmp085ReadInt(0xBA);
- mc = bmp085ReadInt(0xBC);
- md = bmp085ReadInt(0xBE);
- }
- // Calculate temperature in deg C
- float bmp085GetTemperature(unsigned int ut){
- long x1, x2;
- x1 = (((long)ut - (long)ac6)*(long)ac5) >> 15;
- x2 = ((long)mc << 11)/(x1 + md);
- b5 = x1 + x2;
- float temp = ((b5 + 8)>>4);
- temp = temp /10;
- return temp;
- }
- // Calculate pressure given up
- // calibration values must be known
- // b5 is also required so bmp085GetTemperature(...) must be called first.
- // Value returned will be pressure in units of Pa.
- long bmp085GetPressure(unsigned long up){
- long x1, x2, x3, b3, b6, p;
- unsigned long b4, b7;
- b6 = b5 - 4000;
- // Calculate B3
- x1 = (b2 * (b6 * b6)>>12)>>11;
- x2 = (ac2 * b6)>>11;
- x3 = x1 + x2;
- b3 = (((((long)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 * (unsigned long)(x3 + 32768))>>15;
- b7 = ((unsigned long)(up - b3) * (50000>>OSS));
- if (b7 < 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;
- long temp = p;
- return temp;
- }
- // Read 1 byte from the BMP085 at 'address'
- char bmp085Read(unsigned char address)
- {
- unsigned char data;
- Wire.beginTransmission(BMP085_ADDRESS);
- Wire.write(address);
- Wire.endTransmission();
- Wire.requestFrom(BMP085_ADDRESS, 1);
- while(!Wire.available())
- ;
- return Wire.read();
- }
- // Read 2 bytes from the BMP085
- // First byte will be from 'address'
- // Second byte will be from 'address'+1
- int bmp085ReadInt(unsigned char address)
- {
- unsigned char msb, lsb;
- Wire.beginTransmission(BMP085_ADDRESS);
- Wire.write(address);
- Wire.endTransmission();
- Wire.requestFrom(BMP085_ADDRESS, 2);
- while(Wire.available()<2)
- ;
- msb = Wire.read();
- lsb = Wire.read();
- return (int) msb<<8 | lsb;
- }
- // Read the uncompensated temperature value
- unsigned int bmp085ReadUT(){
- unsigned int ut;
- // Write 0x2E into Register 0xF4
- // This requests a temperature reading
- Wire.beginTransmission(BMP085_ADDRESS);
- Wire.write(0xF4);
- Wire.write(0x2E);
- Wire.endTransmission();
- // Wait at least 4.5ms
- delay(5);
- // Read two bytes from registers 0xF6 and 0xF7
- ut = bmp085ReadInt(0xF6);
- return ut;
- }
- // Read the uncompensated pressure value
- unsigned long bmp085ReadUP(){
- unsigned char msb, lsb, xlsb;
- unsigned long up = 0;
- // Write 0x34+(OSS<<6) into register 0xF4
- // Request a pressure reading w/ oversampling setting
- Wire.beginTransmission(BMP085_ADDRESS);
- Wire.write(0xF4);
- Wire.write(0x34 + (OSS<<6));
- Wire.endTransmission();
- // Wait for conversion, delay time dependent on OSS
- delay(2 + (3<<OSS));
- // Read register 0xF6 (MSB), 0xF7 (LSB), and 0xF8 (XLSB)
- msb = bmp085Read(0xF6);
- lsb = bmp085Read(0xF7);
- xlsb = bmp085Read(0xF8);
- up = (((unsigned long) msb << 16) | ((unsigned long) lsb << 8) | (unsigned long) xlsb) >> (8-OSS);
- return up;
- }
- void writeRegister(int deviceAddress, byte address, byte val) {
- Wire.beginTransmission(deviceAddress); // start transmission to device
- Wire.write(address); // send register address
- Wire.write(val); // send value to write
- Wire.endTransmission(); // end transmission
- }
- int readRegister(int deviceAddress, byte address){
- int v;
- Wire.beginTransmission(deviceAddress);
- Wire.write(address); // register to read
- Wire.endTransmission();
- Wire.requestFrom(deviceAddress, 1); // read a byte
- while(!Wire.available()) {
- // waiting
- }
- v = Wire.read();
- return v;
- }
- float calcAltitude(float pressure){
- float A = pressure/101325;
- float B = 1/5.25588;
- float C = pow(A,B);
- C = 1 - C;
- C = C /0.0000225577;
- return C;
- }
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所有資料51hei提供下載:
bmp085_arduino.rar
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2018-3-7 14:14 上傳
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