Kory Hill
/
BMP085_test
Test program of BMP085 pressure sensor
Fork of BMP085_lib by
Diff: main.cpp
- Revision:
- 2:227f0a670091
- Parent:
- 1:2935199329b2
--- a/main.cpp Mon Nov 05 19:31:55 2012 +0000 +++ b/main.cpp Fri Nov 09 19:28:09 2012 +0000 @@ -2,247 +2,29 @@ * * * -* 1.8 - 3.6V (Vdd) -* 1.62 - 3.6 (Vddio) +* +* * * -*Altitude = 44330*(1-(p/p0)^(1/5.255)) -* set p0 to sealevel pressure -* delta p = 1hPa = 8.43m at sea level * -*/ - -/* -*Pinout: -*pin9 = SDA -*pin10 = SCL -*pin11 = XCLR (digital out; active low; Resets sensor) -*pin12 = EOC ("end of conversation"; signal when conversion finished) -* -* +* +* * */ -class BMP085 -{ - -public: - BMP085(); - //BMP085(); - - float get_temperature(); - long get_pressure(); - void calculations(long); - -protected: - void init(BMP085_OSS); - unsigned short read_short (int, int); - void write_char (int, int, int); - - I2C i2c; - float temperature; - long pressure; - -private: - short AC1, AC2, AC3, B1, B2, MB, MC, MD, OSS; - unsigned short AC4, AC5, AC6; -}; - #include "mbed.h" - -enum bmp085_oss {ULTRALOW, //samples 1 time - STANDARD, //samples twice - HIGH, //samples 4 times - ULTRAHIGH};//samples 8 times - - -I2C i2c(p9, p10); // sda, scl -Serial pc(USBTX, USBRX); // tx, rx - -const int bmp085_address = 0xEE; //address of bmp085 -const int P0 = 101325; //pressure at sea level - - -void bmp085_calibration(void); -void display_calibration(void); -unsigned short read_short(int,int); -void write_char(int,int,int); - -long get_raw_temp(void); -void calculations(long); - -float get_temperature(void); -long get_pressure(void); -float get_altitude(long); - -//short AC1, AC2, AC3, B1, B2, MB, MC, MD, OSS; -//unsigned short AC4, AC5, AC6; - - - - +#include "BMP085.h" int main() { - //Initialize - OSS = STANDARD; //change between enums under bmp085_oss for desired Sampling resolution - - //calibrate - bmp085_calibration(); - display_calibration(); - - long raw_temp = get_raw_temp(); - - calculations(raw_temp); - - //float altitude = get_altitude(pressure); - - //pc.printf("Temperature: %f\n",temperature); - //pc.printf("Pressure: %l\n", pressure); - //pc.printf("Altitude: %f\n", altitude); - - -} - -long get_raw_temp(void) -{ - long raw_temp; - - //Read raw temperature value - write_char(bmp085_address, 0xF4, 0x2E); - wait_ms(4.5); - raw_temp = read_short(bmp085_address, 0xF6); - - return raw_temp; -} - -void calculations(long raw_temp) -{ - long X1, X2, B5; //temperature; - - //Start temperature calculation - X1 = (((long)raw_temp - (long)AC6) * (long)AC5) >> 15; - X2 = ((long)MC << 11) / (X1 + MD); - B5 = X1 + X2; - temperature = ((B5 + 8) >> 4); - - temperature = ((float)temperature / 10.0); - - pc.printf("Temperature: %f\n",temperature); - - - long raw_pressure, B6, B3, X3; - unsigned long B4, B7; - - //Read raw pressure value - write_char(bmp085_address, 0xf4, 0x34 | (OSS << 6)); - wait_ms(5); - raw_pressure = read_short(bmp085_address, 0xF6) >> (8 - OSS); - - //Start Pressure calculation - B6 = B5 - 4000; - X1 = (B2 * (B6 * B6) >> 12) >> 11; - X2 = (AC2 * B6) >> 11; - X3 = X1 + X2; - B3 = (((AC1 * 4 + X3) << OSS + 2) / 4); - 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)(raw_pressure - B3) * (50000 >> OSS)); - if (B7 < 0x80000000) - pressure = (B7 *2) / B4; - else - pressure = (B7 / B4) * 2; - - X1 = (pressure >> 8) * (pressure >>8); - X1 = (X1 * 3038) >>16; - X2 = (-7357 * pressure) >>16; - pressure += (X1 + X2 + 3791)>>4; - - pc.printf("Pressure: %f\n", pressure); - -} -float get_temperature(void) -{ - return temperature; -} - -long get_pressure(void) -{ - return pressure; + alt_sensor.display_cal_param(&pc); + + pc.printf("Temperature: %d\r\n", alt_sensor.get_temperature()); + pc.printf("Pressure: %d\r\n", alt_sensor.get_pressure()); + pc.printf("Altitude: %f\r\n", alt_sensor.get_altitude_ft()); } - -float get_altitude(long pressure) -{ - float altitude; - - altitude = (float)44330 * (1 - pow(( pressure/P0), 0.190295)); - - pc.printf("Altitude: %f\n", altitude); - return altitude; - -} - -void bmp085_calibration(void) -{ - AC1 = read_short(bmp085_address, 0xAA); - AC2 = read_short(bmp085_address, 0xAC); - AC3 = read_short(bmp085_address, 0xAE); - AC4 = read_short(bmp085_address, 0xB0); - AC5 = read_short(bmp085_address, 0xB2); - AC6 = read_short(bmp085_address, 0xB4); - B1 = read_short(bmp085_address, 0xB6); - B2 = read_short(bmp085_address, 0xB8); - MB = read_short(bmp085_address, 0xBA); - MC = read_short(bmp085_address, 0xBC); - MD = read_short(bmp085_address, 0xBE); - -} + -void display_calibration(void) -{ - pc.printf("Calibration Values:\n"); - pc.printf("AC1 = %d\n",AC1); - pc.printf("AC2 = %d\n",AC2); - pc.printf("AC3 = %d\n",AC3); - pc.printf("AC4 = %d\n",AC4); - pc.printf("AC5 = %d\n",AC5); - pc.printf("AC6 = %d\n",AC6); - pc.printf("B1 = %d\n",B1); - pc.printf("B2 = %d\n",B2); - pc.printf("MB = %d\n",MB); - pc.printf("MC = %d\n",MC); - pc.printf("MD = %d\n",MD); -} - -unsigned short read_short(int device_address,int address) -{ - unsigned short value; - - i2c.start(); - i2c.write(device_address); - i2c.write(address); - - i2c.start(); - i2c.write(device_address | 1); - value = i2c.read(1) << 8; - value |= i2c.read(0); - i2c.stop(); - - return value; - -} - -void write_char(int device_address, int address, int data) -{ - i2c.start(); - i2c.write(device_address); - i2c.write(address); - i2c.write(data); - i2c.stop(); -} -