Revision 0:ed5a906c8e44, committed 2014-03-09

Comitter:

spiridion

Date:

Sun Mar 09 16:53:11 2014 +0000

Commit message:

first release

Changed in this revision

diff -r 000000000000 -r ed5a906c8e44 HIH6130.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/HIH6130.cpp	Sun Mar 09 16:53:11 2014 +0000
@@ -0,0 +1,84 @@
+/*
+  @file HIH6130.cpp
+  
+  @brief Humidity and Temperature Sensor HIH6130 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 I2C communication with HIH6130 can be found here: 
+  http://mbed.org/media/uploads/spiridion/i2c_comms_humidicon_tn_009061-2-en_final_07jun12.pdf
+*/
+ 
+#include "HIH6130.h"
+#include "mbed.h"
+
+HIH6130::HIH6130(PinName sda, PinName scl, int address) : m_i2c(sda,scl), m_addr(address)
+{
+    m_temperature = UNSET_HI6130_TEMPERATURE_VALUE;
+    m_humidity = UNSET_HI6130_HUMIDITY_VALUE;
+}
+
+HIH6130::HIH6130(I2C& i2c, int address) : m_i2c(i2c), m_addr(address)
+{
+    m_temperature = UNSET_HI6130_TEMPERATURE_VALUE;
+    m_humidity = UNSET_HI6130_HUMIDITY_VALUE;
+}
+
+int HIH6130::ReadData(float* pTemperature, float* pHumidity)
+{
+    int rsl = Measurement();
+    
+    if (rsl)
+    { 
+        m_temperature = TrueTemperature();
+        m_humidity = TrueHumidity();
+    }
+    else
+    {
+        m_temperature = UNSET_HI6130_TEMPERATURE_VALUE;
+        m_humidity = UNSET_HI6130_HUMIDITY_VALUE;
+    }
+    
+    if (pTemperature)
+        *pTemperature = m_temperature;
+    if (pHumidity)
+        *pHumidity = m_humidity;
+
+    return rsl;
+}
+
+float HIH6130::TrueTemperature()
+{   
+    // T = T_output / (2^14-2)*165-40
+    return ( ( ((unsigned int)m_data[2] << 8) | (unsigned int)m_data[3] ) >> 2 ) * 0.010072F - 40;  
+}
+
+float HIH6130::TrueHumidity()
+{
+    // H = H_output /(2^14-2)*100
+    return ( (((unsigned int)m_data[0] & 0x3f) << 8) | ((unsigned int)m_data[1] & 0xff) ) * 0.006104F;
+}
+
+int HIH6130::Measurement()
+{
+    int errors;
+
+    // Humidity and temperature measurement request
+    errors = m_i2c.write(m_addr, m_data, 1);
+    
+    wait_ms(10);
+    
+    // Humidity and temperature data fetch
+    errors += m_i2c.read(m_addr, m_data, 4);
+
+    //  Check data validity
+    if ( errors || !(m_data[0] & 0xC0)) 
+        return 0;
+        
+    return 1;
+}

diff -r 000000000000 -r ed5a906c8e44 HIH6130.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/HIH6130.h	Sun Mar 09 16:53:11 2014 +0000
@@ -0,0 +1,121 @@
+/*
+  @file HIH6130.h
+  
+  @brief Humidity and Temperature Sensor HIH6130 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 I2C communication with HIH6130 can be found here: 
+  http://mbed.org/media/uploads/spiridion/i2c_comms_humidicon_tn_009061-2-en_final_07jun12.pdf
+*/
+
+#ifndef HIH6130_H
+#define HIH6130_H
+
+#include "mbed.h"
+
+///  default address is not 0X27, as stated in the documentation, but 0x4E (0x27<<1 ?) 
+#define HIH6130_I2C_ADDRESS 0x4E 
+
+#define UNSET_HI6130_HUMIDITY_VALUE -100.F
+#define UNSET_HI6130_TEMPERATURE_VALUE -273.15F // absolute zero
+
+/** HIH6130 class.
+ *  Read humidity and temperature from the HIH6130 Breakout I2C sensor
+ *
+ * Example:
+ * @code
+ * #include "mbed.h"
+ * #include "HIH6130.h"
+ * 
+ * #if defined(TARGET_LPC1768)
+ *     #define PIN_SDA p9
+ *     #define PIN_SCL p10
+ * #elif defined(TARGET_KL25Z) // watch out for the PTE0/PTE1 mixed up in the KL25Z doc 
+ *     #define PIN_SDA PTE0
+ *     #define PIN_SCL PTE1
+ * #endif
+ * 
+ * int main() 
+ * {    
+ *     HIH6130 hih6130(PIN_SDA, PIN_SCL);
+ *     float humidity, temperature;
+ *     
+ *     while(1) {        
+ *         if (hih6130.ReadData(&humidity, &temperature))
+ *             printf("Humidity(%%RH): %8.2f \t Temperature(C): %8.2f\n", humidity, temperature);  
+ *         wait(1);
+ *     }
+ * }
+ * @endcode
+ */
+class HIH6130 
+{
+
+public:
+
+    /** Create a HIH6130 instance
+     * @param sda pin 
+     * @param scl pin 
+     * @param address: I2C slave address 
+     */
+    HIH6130(PinName sda, PinName scl, int address = HIH6130_I2C_ADDRESS); 
+
+    /** Create a HIH6130 instance
+     * @param i2c object
+     * @param address: I2C slave address 
+     */
+    HIH6130(I2C& i2c, int address = HIH6130_I2C_ADDRESS); 
+
+    /** Read relative humidity and temperature from the HIH6130.
+     * @param humidity (%RH) 
+     * @param temperature (C) 
+     * @returns
+     *   1 on success,
+     *   0 on error
+     */    
+    int ReadData(float* pTemperature=NULL, float* pHumidity=NULL);
+
+    /** Get temperature from a previous measurement 
+     *  
+     * @returns
+     *   temperature (C)
+     */    
+    float GetTemperature() {return m_temperature;}
+
+    /** Get relative humidity from a previous measurement
+     *
+     * @returns
+     *   relative humidity (%RH)
+     */    
+    float GetHumidity() {return m_humidity;}; 
+
+protected:
+
+    /** Measurement request and data fetch
+     */    
+    int Measurement();
+
+    /** Calculation of the temperature from the digital output
+     */    
+    float TrueTemperature();
+    
+    /** Calculation of the humidity from the digital output
+     */    
+    float TrueHumidity();
+    
+    float m_temperature;  
+    float m_humidity;  
+
+    I2C m_i2c;   
+    int m_addr;  
+     
+    char m_data[4];    
+};
+
+#endif