CORE
ロケット用プログラム
Dependencies: mbed
Diff: BMP180/BMP180.cpp
- Revision:
- 0:d58274531d38
diff -r 000000000000 -r d58274531d38 BMP180/BMP180.cpp
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/BMP180/BMP180.cpp Wed Sep 11 06:37:20 2019 +0000
@@ -0,0 +1,226 @@
+/*
+ @file BMP180.cpp
+
+ @brief Barometric Pressure and Temperature Sensor BMP180 Breakout I2C Library
+
+ @Author spiridion (http://mailme.spiridion.net)
+
+ Tested on LPC1768 and FRDM-KL25Z
+
+ Copyright (c) 2014 spiridion
+ Released under the MIT License (see http://mbed.org/license/mit)
+
+ Documentation regarding the BMP180 can be found here:
+ http://mbed.org/media/uploads/spiridion/bst-bmp180-ds000-09.pdf
+*/
+
+#include "BMP180.h"
+#include "mbed.h"
+
+// Uncomment to test the documentation algorithm against the documentation example
+// Result should be 699.64 hPa and 15°C
+// #define BMP180_TEST_FORMULA
+
+BMP180::BMP180(PinName sda, PinName scl, int address)
+ : m_i2c(sda,scl), m_addr(address)
+{
+ m_altitude = 0;
+ m_oss = BMP180_OSS_NORMAL;
+ m_temperature = UNSET_BMP180_TEMPERATURE_VALUE;
+ m_pressure = UNSET_BMP180_PRESSURE_VALUE;
+}
+
+BMP180::BMP180(I2C& i2c, int address)
+ : m_i2c(i2c), m_addr(address)
+{
+ m_altitude = 0;
+ m_oss = BMP180_OSS_NORMAL;
+ m_temperature = UNSET_BMP180_TEMPERATURE_VALUE;
+ m_pressure = UNSET_BMP180_PRESSURE_VALUE;
+}
+
+int BMP180::Initialize(float altitude, int overSamplingSetting)
+{
+ char data[22];
+ int errors = 0;
+
+ m_altitude = altitude;
+ m_oss = overSamplingSetting;
+ m_temperature = UNSET_BMP180_TEMPERATURE_VALUE;
+ m_pressure = UNSET_BMP180_PRESSURE_VALUE;
+
+ // read calibration data
+ data[0]=0xAA;
+ errors = m_i2c.write(m_addr, data, 1); // set the eeprom pointer position to 0xAA
+ errors += m_i2c.read(m_addr, data, 22); // read 11 x 16 bits at this position
+ wait_ms(10);
+
+ // store calibration data for further calculus
+ ac1 = data[0] << 8 | data[1];
+ ac2 = data[2] << 8 | data[3];
+ ac3 = data[4] << 8 | data[5];
+ ac4 = data[6] << 8 | data[7];
+ ac5 = data[8] << 8 | data[9];
+ ac6 = data[10] << 8 | data[11];
+ b1 = data[12] << 8 | data[13];
+ b2 = data[14] << 8 | data[15];
+ mb = data[16] << 8 | data[17];
+ mc = data[18] << 8 | data[19];
+ md = data[20] << 8 | data[21];
+
+#ifdef BMP180_TEST_FORMULA
+ ac1 = 408;
+ ac2 = -72;
+ ac3 = -14383;
+ ac4 = 32741;
+ ac5 = 32757;
+ ac6 = 23153;
+ b1 = 6190;
+ b2 = 4;
+ mb = -32768;
+ mc = -8711;
+ md = 2868;
+ m_oss = 0;
+ errors = 0;
+#endif // #ifdef BMP180_TEST_FORMULA
+
+ return errors? 0 : 1;
+}
+
+int BMP180::ReadData(float* pTemperature, float* pPressure)
+{
+ long t, p;
+
+ if (!ReadRawTemperature(&t) || !ReadRawPressure(&p))
+ {
+ m_temperature = UNSET_BMP180_TEMPERATURE_VALUE;
+ m_pressure = UNSET_BMP180_PRESSURE_VALUE;
+ return 0;
+ }
+
+ m_temperature = TrueTemperature(t);
+ m_pressure = TruePressure(p);
+
+ if (pPressure)
+ *pPressure = m_pressure;
+ if (pTemperature)
+ *pTemperature = m_temperature;
+
+ return 1;
+}
+
+int BMP180::ReadRawTemperature(long* pUt)
+{
+ int errors = 0;
+ char data[2];
+
+ // request temperature measurement
+ data[0] = 0xF4;
+ data[1] = 0x2E;
+ errors = m_i2c.write(m_addr, data, 2); // write 0XF2 into reg 0XF4
+
+ wait_ms(4.5F);
+
+ // read raw temperature data
+ data[0] = 0xF6;
+ errors += m_i2c.write(m_addr, data, 2); // set eeprom pointer position to 0XF6
+ errors += m_i2c.read(m_addr, data, 2); // get 16 bits at this position
+
+#ifdef BMP180_TEST_FORMULA
+ errors = 0;
+#endif // #ifdef BMP180_TEST_FORMULA
+
+ if (errors)
+ return 0;
+ else
+ *pUt = data[0] << 8 | data[1];
+
+#ifdef BMP180_TEST_FORMULA
+ *pUt = 27898;
+#endif // #ifdef BMP180_TEST_FORMULA
+
+ return 1;
+}
+
+int BMP180::ReadRawPressure(long* pUp)
+{
+ int errors = 0;
+ char data[2];
+
+ // request pressure measurement
+ data[0] = 0xF4;
+ data[1] = 0x34 + (m_oss << 6);
+ errors = m_i2c.write(m_addr, data, 2); // write 0x34 + (m_oss << 6) into reg 0XF4
+
+ switch (m_oss)
+ {
+ case BMP180_OSS_ULTRA_LOW_POWER: wait_ms(4.5); break;
+ case BMP180_OSS_NORMAL: wait_ms(7.5); break;
+ case BMP180_OSS_HIGH_RESOLUTION: wait_ms(13.5); break;
+ case BMP180_OSS_ULTRA_HIGH_RESOLUTION: wait_ms(25.5); break;
+ }
+
+ // read raw pressure data
+ data[0] = 0xF6;
+ errors += m_i2c.write(m_addr, data, 1); // set eeprom pointer position to 0XF6
+ errors += m_i2c.read(m_addr, data, 2); // get 16 bits at this position
+
+#ifdef BMP180_TEST_FORMULA
+ errors = 0;
+#endif // #ifdef BMP180_TEST_FORMULA
+
+ if (errors)
+ return 0;
+ else
+ *pUp = (data[0] << 16 | data[1] << 8) >> (8 - m_oss);
+#ifdef BMP180_TEST_FORMULA
+ *pUp = 23843;
+#endif // #ifdef BMP180_TEST_FORMULA
+
+ return 1;
+}
+
+float BMP180::TrueTemperature(long ut)
+{
+ long t;
+
+ // straight out from the documentation
+ x1 = ((ut - ac6) * ac5) >> 15;
+ x2 = ((long)mc << 11) / (x1 + md);
+ b5 = x1 + x2;
+ t = (b5 + 8) >> 4;
+
+ // convert to celcius
+ return t / 10.F;
+}
+
+float BMP180::TruePressure(long up)
+{
+ long p;
+
+ // straight out from the documentation
+ b6 = b5 - 4000;
+ x1 = (b2 * (b6 * b6 >> 12)) >> 11;
+ x2 = ac2 * b6 >> 11;
+ x3 = x1 + x2;
+ b3 = (((ac1 * 4 + x3) << m_oss) + 2) >> 2;
+ 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 >> m_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 = p + ((x1 + x2 + 3791) >> 4);
+
+ // convert to hPa and, if altitude has been initialized, to sea level pressure
+ if (m_altitude == 0.F)
+ return p / 100.F;
+ else
+ return p / (100.F * pow((1.F - m_altitude / 44330.0L), 5.255L));
+}
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