Diff: HIH6130.cpp

Revision:

0:ed5a906c8e44

--- /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;
+}