baro

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API Documentation at this revision

Comitter:
gmatjuara
Date:
Sat Dec 14 04:19:18 2013 +0000
Commit message:
barometer

Changed in this revision

MS5611.cpp Show annotated file Show diff for this revision Revisions of this file
MS5611.h Show annotated file Show diff for this revision Revisions of this file
diff -r 000000000000 -r 669dfadf96c5 MS5611.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MS5611.cpp	Sat Dec 14 04:19:18 2013 +0000
@@ -0,0 +1,152 @@
+/*
+ * mbed library to use a Bosch Sensortec MS5611 sensor
+ * Copyright (c) 2010 Hiroshi Suga
+ * Released under the MIT License: http://mbed.org/license/mit
+ */
+
+/** @file MS5611.cpp
+ * @brief mbed library to use a Bosch Sensortec MS5611 sensor
+ * barometric pressure sensor MS5611 (Bosch Sensortec)
+ * interface: I2C digital
+ */
+
+#include "mbed.h"
+#include "MS5611.h"
+
+#define WEATHER_MS5611 0xee
+#define xpow(x, y) ((long)1 << y)
+
+/**
+ * @brief Initializes interface (private I2C)
+ * @param p_sda port of I2C SDA
+ * @param p_scl port of I2C SCL
+ * @param p_oss parameter of OSS
+ */
+MS5611::MS5611 (PinName p_sda, PinName p_scl, MS5611_oss p_oss) : i2c(p_sda, p_scl) {
+    init(p_oss);
+}
+
+/**
+ * @brief Initializes interface (public I2C)
+ * @param p_i2c instance of I2C class
+ * @param p_oss parameter of OSS
+ */
+MS5611::MS5611 (I2C& p_i2c, MS5611_oss p_oss) : i2c(p_i2c) { 
+    init(p_oss);
+}
+
+/**
+ * @brief Get temperature
+ * @return temperature (`C)
+ */
+float MS5611::get_temperature() {
+    return temperature;
+}
+
+/**
+ * @brief Get pressure
+ * @return pressure (hPa)
+ */
+float MS5611::get_pressure() {
+    return pressure;
+}
+
+/**
+ * @brief Update results
+ */
+void MS5611::update () {
+    long t, p, ut, up, x1, x2, x3, b3, b5, b6;
+    unsigned long b4, b7;
+
+    twi_writechar(WEATHER_MS5611, 0xf4, 0x2e);
+    wait(0.0045); //wait(0.01);
+    ut = twi_readshort(WEATHER_MS5611, 0xf6);
+
+    twi_writechar(WEATHER_MS5611, 0xf4, 0x34 | (oss << 6));
+    wait(0.0045); //wait(0.05);
+    up = twi_readlong(WEATHER_MS5611, 0xf6) >> (8 - oss);
+
+    x1 = (ut - ac6) * ac5 / xpow(2, 15);
+    x2 = (long)mc * xpow(2, 11) / (x1 + md);
+    b5 = x1 + x2;
+    t = (b5 + 8) / xpow(2, 4);
+    temperature = (float)t / 10.0;
+
+    b6 = b5 - 4000;
+    x1 = (b2 * (b6 * b6 / xpow(2, 12))) / xpow(2, 11);
+    x2 = ac2 * b6 / xpow(2, 11);
+    x3 = x1 + x2;
+    b3 = ((((unsigned long)ac1 * 4 + x3) << oss) + 2) / 4;
+    x1 = ac3 * b6 / xpow(2, 13);
+    x2 = (b1 * (b6 * b6 / xpow(2, 12))) / xpow(2, 16);
+    x3 = ((x1 + x2) + 2) / xpow(2, 2);
+    b4 = ac4 * (unsigned long)(x3 + 32768) / xpow(2, 15);
+    b7 = ((unsigned long)up - b3) * (50000 >> oss);
+    if (b7 < (unsigned long)0x80000000) {
+        p = (b7 * 2) / b4;
+    } else {
+        p = (b7 / b4) * 2;
+    }
+    x1 = (p / xpow(2, 8)) * (p / xpow(2, 8));
+    x1 = (x1 * 3038) / xpow(2, 16);
+    x2 = (-7357 * p) / xpow(2, 16);
+    p = p + (x1 + x2 + 3791) / xpow(2, 4);
+    pressure = (float)p / 100.0;
+}
+
+void MS5611::init (MS5611_oss p_oss) {
+    ac1 = twi_readshort(WEATHER_MS5611, 0xaa);
+    ac2 = twi_readshort(WEATHER_MS5611, 0xac);
+    ac3 = twi_readshort(WEATHER_MS5611, 0xae);
+    ac4 = twi_readshort(WEATHER_MS5611, 0xb0);
+    ac5 = twi_readshort(WEATHER_MS5611, 0xb2);
+    ac6 = twi_readshort(WEATHER_MS5611, 0xb4);
+    b1 = twi_readshort(WEATHER_MS5611, 0xb6);
+    b2 = twi_readshort(WEATHER_MS5611, 0xb8);
+    mb = twi_readshort(WEATHER_MS5611, 0xba);
+    mc = twi_readshort(WEATHER_MS5611, 0xbc);
+    md = twi_readshort(WEATHER_MS5611, 0xbe);
+    oss = p_oss;
+}
+
+unsigned short MS5611::twi_readshort (int id, int addr) {
+    unsigned short i;
+
+    i2c.start();
+    i2c.write(id);
+    i2c.write(addr);
+
+    i2c.start();
+    i2c.write(id | 1);
+    i = i2c.read(1) << 8;
+    i |= i2c.read(0);
+    i2c.stop();
+
+    return i;
+}
+
+unsigned long MS5611::twi_readlong (int id, int addr) {
+    unsigned long i;
+
+    i2c.start();
+    i2c.write(id);
+    i2c.write(addr);
+
+    i2c.start();
+    i2c.write(id | 1);
+    i = i2c.read(1) << 16;
+    i |= i2c.read(1) << 8;
+    i |= i2c.read(0);
+    i2c.stop();
+
+    return i;
+}
+
+void MS5611::twi_writechar (int id, int addr, int dat) {
+
+    i2c.start();
+    i2c.write(id);
+    i2c.write(addr);
+    i2c.write(dat);
+    i2c.stop();
+}
diff -r 000000000000 -r 669dfadf96c5 MS5611.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MS5611.h	Sat Dec 14 04:19:18 2013 +0000
@@ -0,0 +1,57 @@
+/*
+ * mbed library to use a Bosch Sensortec MS5611 sensor
+ * Copyright (c) 2010 Hiroshi Suga
+ * Released under the MIT License: http://mbed.org/license/mit
+ */
+ 
+/** @file MS5611.h
+ * @brief mbed library to use a Bosch Sensortec MS5611 sensor
+ * barometric pressure sensor MS5611 (Bosch Sensortec)
+ * interface: I2C digital
+ */
+ 
+#ifndef MS5611_H
+#define MS5611_H
+
+#include "mbed.h"
+
+/**
+ * @brief over sampling setting
+ */
+enum MS5611_oss {
+    MS5611_oss1 = 0, ///< ultra low power (1 time)
+    MS5611_oss2 = 1, ///< standard (2 times)
+    MS5611_oss4 = 2, ///< high resolution (4 times)
+    MS5611_oss8 = 3  ///< ultra high resolution (8 times)
+};
+
+/**
+ * @brief MS5611 class
+ */
+class MS5611 
+{
+public:
+    MS5611(PinName p_sda, PinName p_scl, MS5611_oss p_oss = MS5611_oss1);
+    MS5611(I2C& p_i2c, MS5611_oss p_oss = MS5611_oss1);
+
+    float get_temperature();
+    float get_pressure();
+    void update();
+
+protected:
+    void init(MS5611_oss);
+    unsigned short twi_readshort (int, int);
+    unsigned long twi_readlong (int, int);
+    void twi_writechar (int, int, int);
+
+    I2C i2c;
+    float temperature;
+    float pressure;
+
+private:
+
+    short ac1, ac2, ac3, b1, b2, mb, mc, md, oss;
+    unsigned short ac4, ac5, ac6;
+};
+
+#endif
\ No newline at end of file