Diff: htu21d.h

Revision:

0:2dab43acb3a4

Child:

1:d3ed713f8354

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/htu21d.h	Wed May 14 00:31:30 2014 +0000
@@ -0,0 +1,131 @@
+/**
+ */
+
+#ifndef HTU21D_H
+#define HTU21D_H
+
+#include "mbed.h"
+
+//Defines for HTU21D
+#define HTU21Di2cWRITE      0x80
+#define HTU21Di2cREAD       0x81
+
+#define HTU21DWRITEUSER     0xE6
+#define HTU21DREADUSER      0xE7
+#define HTU21DtempNOHOLD    0xF3
+#define HTU21DhumNOHOLD     0xF5
+#define HTU21DRESET         0xFE
+
+#define HTU21DHEATER        0x04
+
+
+/**
+ * Honeywell HTU21D digital humidity and temperature sensor.
+ */
+class htu21d {
+
+public:
+    /**
+     * Constructor.
+     *
+     * @param sda and scl, mbed I2C interface pins.
+     */
+    htu21d(PinName sda, PinName scl);
+    /**
+     * De-constructor.
+     *
+     * @param --none--.
+     */
+    ~htu21d();
+    /**
+     * Get HTU21D Temperature.
+     * 
+     * @param --none--.
+     *
+     * @return success / failure of HTU21D i2c access. 1 = ok, 0 = error.
+    */
+    int softReset();
+    /**
+     * Get HTU21D user register.
+     * 
+     * @param --none--.
+     *
+     * @return success / failure of HTU21D i2c access. 1 = ok, 0 = error.
+    */
+    uint8_t getUserReg();
+    /**
+     * Turn ON the heater in the HTU21D.
+     * 
+     * @param --none--.
+     *
+     * @return success / failure of HTU21D i2c access. 1 = ok, 0 = error.
+    */
+    int heaterOn();
+    /**
+     * Turn OFF the heater in the HTU21D.
+     * 
+     * @param --none--.
+     *
+     * @return --none--.
+    */
+    int heaterOff();
+    /**
+     * Get heater on/off status in the HTU21D.
+     * 
+     * @param --none--.
+     *
+     * @return 4 = on, 0 = 0ff.
+    */
+    uint8_t getHeater();
+    /**
+     * Do a reset on the HTU21D.
+     * 
+     * @param --none--.
+     *
+     * @return float of Temperature in degrees C.  255.0 if error.
+    */
+    float getTemp();
+    /**
+     * Get HTU21D Humidity.
+     * 
+     * @param --none--.
+     *
+     * @return float of Humidity in percentage.  255.0 if error.
+    */
+    float getHum();
+    /**
+     * Claculate the Dew Point.
+     * 
+     * @param MUST run getTemp and getHum first!!
+     *
+     * @return float of Dew Point.
+    */
+    float getDewPt();
+    /**
+     * Claculate the Dew Point. 5x faster than getDewPt().
+     * 
+     * @param MUST run getTemp and getHum first!!
+     *
+     * @return float of Dew Point.
+    */
+    float getDewPtFast();
+
+ 
+
+private:
+    I2C _i2c;
+    /**
+     * I2C access for getting raw Temperature and Humidity data.
+     * 
+     * @param 8 bit HTU21D register to get data from. Must use non-blocking regs.
+     *
+     * @return 16 bit raw i2c data, ANDed to 14 bits 0xFFFC. 0000 if error.
+    */
+    uint16_t getData(uint8_t reg);
+    double theTempIs;
+    double theHumIs;
+    float getTrash();
+
+};
+
+#endif