lib: Add main LM75A temperature sensor library

Add the most important part of this project (the lib).
A keywords.txt file has been added to improve lib display
in arduino interface.

Author: QuentinCG

LM75A/LM75A.cpp

@@ -0,0 +1,106 @@
+/*
+ * \brief I2C LM75A temperature sensor library (implementation)
+ *
+ * \author Quentin Comte-Gaz <[email protected]>
+ * \date 8 July 2016
+ * \license MIT License (contact me if too restrictive)
+ * \copyright Copyright (c) 2016 Quentin Comte-Gaz
+ * \version 1.0
+ */
+
+#include "LM75A.h"
+#include <Wire.h>
+
+namespace LM75AConstValues
+{
+
+const int LM75A_BASE_ADDRESS = 0x48;
+
+const float LM75A_DEGREES_RESOLUTION = 0.125;
+
+const int LM75A_REG_ADDR_TEMP = 0;
+//const int LM75A_REG_ADDR_CONF = 1;  // Not used for now
+//const int LM57A_REG_ADDR_THYST = 2; // Not used for now
+//const int LM57A_REG_ADDR_TOS = 3;   // Not used for now
+
+}
+
+using namespace LM75AConstValues;
+
+LM75A::LM75A(bool A0_value, bool A1_value, bool A2_value)
+{
+  _i2c_device_address = LM75A_BASE_ADDRESS;
+
+  if (A0_value) {
+    _i2c_device_address += 1;
+  }
+
+  if (A1_value) {
+    _i2c_device_address += 2;
+  }
+
+  if (A2_value) {
+    _i2c_device_address += 4;
+  }
+
+  Wire.begin();
+}
+
+float LM75A::fahrenheitToDegrees(float temperature_in_fahrenheit)
+{
+  return ((temperature_in_fahrenheit - 32.0) / 1.8);
+}
+
+float LM75A::degreesToFahrenheit(float temperature_in_degrees)
+{
+  return ((temperature_in_degrees * 1.8) + 32.0);
+}
+
+float LM75A::getTemperatureInFahrenheit() const
+{
+  return degreesToFahrenheit(getTemperatureInDegrees());
+}
+
+float LM75A::getTemperatureInDegrees() const
+{
+  uint16_t real_result = INVALID_LM75A_TEMPERATURE;
+  uint16_t i2c_received = 0;
+
+  // Go to temperature data register
+  Wire.beginTransmission(_i2c_device_address);
+  Wire.write(LM75A_REG_ADDR_TEMP);
+  if(Wire.endTransmission()) {
+    // Transmission error
+    return real_result;
+  }
+
+  // Get content
+  if (Wire.requestFrom(_i2c_device_address, 2)) {
+    Wire.readBytes((uint8_t*)&i2c_received, 2);
+  } else {
+    // Can't read temperature
+    return real_result;
+  }
+
+  // Modify the value (only 11 MSB are relevant if swapped)
+  uint16_t refactored_value;
+  uint8_t* ptr = (uint8_t*)&refactored_value;
+
+  // Swap bytes
+  *ptr = *((uint8_t*)&i2c_received + 1);
+  *(ptr + 1) = *(uint8_t*)&i2c_received;
+
+  // Shift data (left-aligned)
+  refactored_value >>= 5;
+
+  // Relocate negative bit (11th bit to 16th bit)
+  if (refactored_value & 0x0400) {
+    refactored_value &= 0x03FF;
+    refactored_value |= 0x8000;
+  }
+
+  // Real value can be calculated with sensor resolution
+  real_result = (float)refactored_value * LM75A_DEGREES_RESOLUTION;
+
+  return (float)refactored_value * LM75A_DEGREES_RESOLUTION;
+}

LM75A/LM75A.h

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+/*
+ * \brief I2C LM75A temperature sensor library
+ *
+ * \author Quentin Comte-Gaz <[email protected]>
+ * \date 8 July 2016
+ * \license MIT License (contact me if too restrictive)
+ * \copyright Copyright (c) 2016 Quentin Comte-Gaz
+ * \version 1.0
+ */
+
+#ifndef LM75A_h
+#define LM75A_h
+
+#if defined(ARDUINO) && ARDUINO >= 100
+#include "Arduino.h"
+#else
+#include "WProgram.h"
+#endif
+
+#define INVALID_LM75A_TEMPERATURE 1000
+
+class LM75A
+{
+  public:
+    /*!
+     * \brief LM75A Initialize I2C LM75A Temperature sensor instance
+     * \param A0_value (bool) A0 Pin value (used for address)
+     * \param A1_value (bool) A1 Pin value (used for address)
+     * \param A2_value (bool) A2 Pin value (used for address)
+     */
+    LM75A(bool A0_value = false, bool A1_value = false, bool A2_value = false);
+
+    /*!
+     * \brief getTemperatureInDegrees Get temperature from LM75A sensor in degrees
+     * \return (float) Sensor temperature in degrees (return INVALID_LM75A_TEMPERATURE if error happened)
+     */
+    float getTemperatureInDegrees() const;
+
+    /*!
+     * \brief getTemperatureInFahrenheit Get temperature from LM75A sensor in fahrenheit
+     * \return (float) Sensor temperature in fahrenheit (return INVALID_LM75A_TEMPERATURE if error happened)
+     */
+    float getTemperatureInFahrenheit() const;
+
+    /*!
+     * \brief fahrenheitToDegrees Convert temperature from fahrenheit to degrees
+     */
+    static float fahrenheitToDegrees(float temperature_in_fahrenheit);
+
+    /*!
+     * \brief degreesToFahrenheit Convert temperature from degrees to fahrenheit
+     */
+    static float degreesToFahrenheit(float temperature_in_degrees);
+
+  private:
+    int _i2c_device_address;
+};
+
+#endif //LM75A_h
+

LM75A/keywords.txt

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+LM75A	KEYWORD1
+getTemperatureInDegrees	KEYWORD2
+getTemperatureInFahrenheit	KEYWORD2
+fahrenheitToDegrees	KEYWORD2
+degreesToFahrenheit	KEYWORD2
+INVALID_LM75A_TEMPERATURE	KEYWORD2