Handling of multiple I2C network (following #5 issue) (#6)

* Test for #5 issue request (TwoWire handling)

* Preparation of 1.2 release following #5 feature request

- Adding 2 examples (one with 2 sensors on same I2C, one with 2 sensors
  on different I2C)
- Improving explanations
- 1.1 -> 1.2

#5

Author: QuentinCG

LM75A.cpp

@@ -2,10 +2,10 @@
  * \brief I2C LM75A temperature sensor library (implementation)
  *
  * \author Quentin Comte-Gaz <quentin@comte-gaz.com>
- * \date 27 December 2021
+ * \date 05 January 2022
  * \license MIT License (contact me if too restrictive)
- * \copyright Copyright (c) 2021 Quentin Comte-Gaz
- * \version 1.1
+ * \copyright Copyright (c) 2022 Quentin Comte-Gaz
+ * \version 1.2
  */
 
 #include "LM75A.h"
@@ -27,7 +27,13 @@ const int LM75A_REG_ADDR_TEMP = 0;
 
 using namespace LM75AConstValues;
 
-LM75A::LM75A(bool A0_value, bool A1_value, bool A2_value)
+LM75A::LM75A(
+  #ifdef USE_TWO_WIRE_FOR_LM75A
+  TwoWire* specific_wire,
+  #endif
+  bool A0_value,
+  bool A1_value,
+  bool A2_value)
 {
   _i2c_device_address = LM75A_BASE_ADDRESS;
 
@@ -47,7 +53,12 @@ LM75A::LM75A(bool A0_value, bool A1_value, bool A2_value)
     _i2c_device_address += 4;
   }
 
+  // Select Wire (if one I2C range) or TwoWire (if two I2C range)
+  #ifdef USE_TWO_WIRE_FOR_LM75A
+  _specific_wire = specific_wire;
+  #else
   Wire.begin();
+  #endif
 }
 
 float LM75A::fahrenheitToDegrees(float temperature_in_fahrenheit)
@@ -78,6 +89,26 @@ float LM75A::getTemperatureInDegrees() const
   uint16_t i2c_received = 0;
 
   // Go to temperature data register
+  #ifdef USE_TWO_WIRE_FOR_LM75A
+  _specific_wire->beginTransmission(_i2c_device_address);
+  _specific_wire->write(LM75A_REG_ADDR_TEMP);
+  if (_specific_wire->endTransmission())
+  {
+    // Transmission error
+    return real_result;
+  }
+
+  // Get content
+  if (_specific_wire->requestFrom(_i2c_device_address, 2))
+  {
+    _specific_wire->readBytes((uint8_t*)&i2c_received, 2);
+  }
+  else
+  {
+    // Can't read temperature
+    return real_result;
+  }
+  #else
   Wire.beginTransmission(_i2c_device_address);
   Wire.write(LM75A_REG_ADDR_TEMP);
   if (Wire.endTransmission())
@@ -96,6 +127,7 @@ float LM75A::getTemperatureInDegrees() const
     // Can't read temperature
     return real_result;
   }
+  #endif
 
   // Modify the value (only 11 MSB are relevant if swapped)
   int16_t refactored_value;

LM75A.h

@@ -1,11 +1,16 @@
 /*
  * \brief I2C LM75A temperature sensor library
  *
+ * This library can :
+ *   - Show a LM75A sensor temperature in Degrees and Fahrenheit
+ *   - Use multiple LM75A sensors on the same I2C network (by changing A0/A1/A2 LM75A pin state)
+ *   - Use multiple LM75A sensors on default I2C board or using multi-I2C board logic (TwoWire) if available (this doubles the number of usable LM75A on compatible boards)
+ *
  * \author Quentin Comte-Gaz <quentin@comte-gaz.com>
- * \date 8 July 2016 & 14 January 2018
+ * \date 05 January 2022
  * \license MIT License (contact me if too restrictive)
- * \copyright Copyright (c) 2016 Quentin Comte-Gaz
- * \version 1.1
+ * \copyright Copyright (c) 2022 Quentin Comte-Gaz
+ * \version 1.2
  */
 
 #ifndef LM75A_h
@@ -17,18 +22,32 @@
 #include "WProgram.h"
 #endif
 
+#include <Wire.h>
+
+// TODO: Uncomment this line if you want to use TwoWire
+// #define USE_TWO_WIRE_FOR_LM75A 1
+
 #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)
+     * \param specific_wire (TwoWire*, needed ONLY if USE_TWO_WIRE_FOR_LM75A is defined BEFORE include of this header)
+     *                      This wire will be used instead of default board "Wire". It must be initialized with "TwoWire::begin"
+     * \param A0_value (bool) A0 Pin value (connected to ground = false, this will be used for I2C address)
+     * \param A1_value (bool) A1 Pin value (connected to ground = false, this will be used for I2C address)
+     * \param A2_value (bool) A2 Pin value (connected to ground = false, this will be used for I2C address)
      */
-    LM75A(bool A0_value = false, bool A1_value = false, bool A2_value = false);
+    LM75A(
+          #ifdef USE_TWO_WIRE_FOR_LM75A
+          TwoWire* specific_wire,
+          #endif
+          bool A0_value = false,
+          bool A1_value = false,
+          bool A2_value = false
+          );
 
     /*!
      * \brief getTemperatureInDegrees Get temperature from LM75A sensor in degrees
@@ -54,6 +73,9 @@ class LM75A
 
   private:
     int _i2c_device_address;
+    #ifdef USE_TWO_WIRE_FOR_LM75A
+    TwoWire* _specific_wire;
+    #endif
 };
 
 #endif //LM75A_h

README.md

@@ -1,15 +1,17 @@
 # I2C Temperature Sensor (LM75A) Library for Arduino
 [![Build Status](https://travis-ci.org/QuentinCG/Arduino-LM75A-Temperature-Sensor-Library.svg?branch=master)](https://travis-ci.org/QuentinCG/Arduino-LM75A-Temperature-Sensor-Library) [![Codacy Badge](https://api.codacy.com/project/badge/Grade/4264aac910e4471584e5af61e65497d4)](https://www.codacy.com/manual/QuentinCG/Arduino-LM75A-Temperature-Sensor-Library?utm_source=github.com&utm_medium=referral&utm_content=QuentinCG/Arduino-LM75A-Temperature-Sensor-Library&utm_campaign=Badge_Grade) [![License: MIT](https://img.shields.io/badge/License-MIT-brightgreen.svg)](https://github.com/QuentinCG/Arduino-LM75A-Temperature-Sensor-Library/blob/master/LICENSE.md) [![Donate](https://img.shields.io/badge/Donate-PayPal-blue.svg)](https://paypal.me/QuentinCG)
- 
+
 ## What is it
 
-This library (with example) is designed to be integrated in projects using LM75A sensors to get temperature.
+This library (with example) is designed to be integrated in projects using LM75A sensors to get temperature with most Arduino boards.
+
+You'll be able to use between 1 and 8 LM75A sensor on a single board (or up to 16 if your board handles multiple I2C).
 
 <img src="device.png" width="300">
 
 ## How to install
 
-1) Download <a target="_blank" href="https://github.com/QuentinCG/Arduino-LM75A-Temperature-Sensor-Library/releases/download/1.1.0/LM75A_v1_1_0.zip">latest release</a>
+1) Download <a target="_blank" href="https://github.com/QuentinCG/Arduino-LM75A-Temperature-Sensor-Library/releases/download/1.2.0/LM75A_v1_2_0.zip">latest release</a>
 
 2) On your Arduino IDE, click "Sketch" menu and then "Include Library > Add .ZIP Libraries"
 
@@ -30,14 +32,24 @@ This library (with example) is designed to be integrated in projects using LM75A
 
 <img src="schematics.png" width="400">
 
+(Note: SDA and SCL of your board may change depending on your Arduino board)
+
 ## Examples
 
-One example is provided with this library:
+Three examples are provided with this library:
 
-### Show temperature in degrees and fahrenheit every second
+### Show temperature in degrees and fahrenheit every second (1 sensor)
 
 <a target="_blank" href="https://github.com/QuentinCG/Arduino-LM75A-Temperature-Sensor-Library/blob/master/examples/LM75A_ShowTemperature/LM75A_ShowTemperature.ino">Link to source code</a>
 
+### Show temperature in degrees and fahrenheit every second (2 sensors in same I2C network)
+
+<a target="_blank" href="https://github.com/QuentinCG/Arduino-LM75A-Temperature-Sensor-Library/blob/master/examples/LM75A_ShowTemperature2Sensors/LM75A_ShowTemperature2Sensors.ino">Link to source code</a>
+
+### Show temperature in degrees and fahrenheit every second (2 sensors in different I2C network)
+
+<a target="_blank" href="https://github.com/QuentinCG/Arduino-LM75A-Temperature-Sensor-Library/blob/master/examples/LM75A_MultiI2cWire/LM75A_MultiI2cWire.ino">Link to source code</a>
+
 ## License
 
 This project is under MIT license. This means you can use it as you want (just don't delete the library header).
@@ -48,4 +60,5 @@ If you want to add more examples or improve the library, just create a pull requ
 
 ## Contributors
 
-Thank you <a target="_blank" href="https://github.com/andrzejboro">andrzejboro</a> for your help on a bug for negative temperature
+- Thank you <a target="_blank" href="https://github.com/andrzejboro">andrzejboro</a> for your help on a bug for negative temperature.
+- Thank you <a target="_blank" href="https://github.com/damianjwilliams">damianjwilliams</a> for your idea and help on multi I2C handling.

examples/LM75A_MultiI2cWire/LM75A_MultiI2cWire.ino

@@ -0,0 +1,86 @@
+/*
+ * \brief Show temperature in degrees and fahrenheit every second of 2 LM75A connected on DIFFERENT i2C networks (or 'on different i2c wires')
+ *
+ * IMPORTANT NOTE:
+ * To use this example, you need to uncomment "#define USE_TWO_WIRE_FOR_LM75A 1" in LM75A.h IN the library BEFORE importing it (or edit
+ *    C:\Users\{YOUR_USERNAME_HERE}\Documents\Arduino\libraries\LM75A\LM75A.h if already imported)
+ *
+ * \author Quentin Comte-Gaz <quentin@comte-gaz.com>
+ * \date 05 January 2022
+ * \license MIT License (contact me if too restrictive)
+ * \copyright Copyright (c) 2022 Quentin Comte-Gaz
+ * \version 1.2
+ */
+
+#include <LM75A.h>
+
+//Define I2C pins for first I2C wire
+#define SDA_1 27
+#define SCL_1 26
+
+//Define I2C pins for second I2C wire
+#define SDA_2 33
+#define SCL_2 32
+
+//Create the two I2C Bus instances
+TwoWire I2C_one = TwoWire(0);
+TwoWire I2C_two = TwoWire(1);
+
+// Create I2C LM75A instance
+LM75A lm75a_from_I2C_one(&I2C_one, // I2C network to use
+                           false,  // A0 LM75A pin state (connected to ground = false)
+                           false,  // A1 LM75A pin state (connected to ground = false)
+                           false); // A2 LM75A pin state (connected to ground = false)
+
+LM75A lm75a_from_I2C_two(&I2C_two, // I2C network to use
+                           false,  // A0 LM75A pin state (connected to ground = false)
+                           false,  // A1 LM75A pin state (connected to ground = false)
+                           false); // A2 LM75A pin state (connected to ground = false)
+
+void setup(void)
+{
+  Serial.begin(9600);
+
+  Serial.println("Initializing both I2C wires");
+  I2C_one.begin(SDA_1, SCL_1);
+  I2C_two.begin(SDA_2, SCL_2);
+
+  Serial.println("Temperatures from both sensors from 2 different I2C wires will be displayed every second:");
+}
+
+void loop()
+{
+  // Get temperature of both sensors
+  float temperature_in_degrees_one = lm75a_from_I2C_one.getTemperatureInDegrees();
+  float temperature_in_degrees_two = lm75a_from_I2C_two.getTemperatureInDegrees();
+
+  // Display temperature of first sensor
+  if (temperature_in_degrees_one == INVALID_LM75A_TEMPERATURE)
+  {
+    Serial.println("Error while getting temperature of sensor 1");
+  }
+  else
+  {
+    Serial.print("Temperature sensor 1: ");
+    Serial.print(temperature_in_degrees_one);
+    Serial.print(" degrees (");
+    Serial.print(LM75A::degreesToFahrenheit(temperature_in_degrees_one));
+    Serial.println(" fahrenheit)");
+  }
+
+  // Display temperature of second sensor
+  if (temperature_in_degrees_two == INVALID_LM75A_TEMPERATURE)
+  {
+    Serial.println("Error while getting temperature of sensor 2");
+  }
+  else
+  {
+    Serial.print("Temperature sensor 2: ");
+    Serial.print(temperature_in_degrees_two);
+    Serial.print(" degrees (");
+    Serial.print(LM75A::degreesToFahrenheit(temperature_in_degrees_two));
+    Serial.println(" fahrenheit)");
+  }
+
+  delay(1000);
+}

examples/LM75A_ShowTemperature/LM75A_ShowTemperature.ino

@@ -2,18 +2,18 @@
  * \brief Show temperature in degrees and fahrenheit every second
  *
  * \author Quentin Comte-Gaz <quentin@comte-gaz.com>
- * \date 27 December 2021
+ * \date 05 January 2022
  * \license MIT License (contact me if too restrictive)
- * \copyright Copyright (c) 2021 Quentin Comte-Gaz
- * \version 1.0
+ * \copyright Copyright (c) 2022 Quentin Comte-Gaz
+ * \version 1.2
  */
 
 #include <LM75A.h>
 
 // Create I2C LM75A instance
-LM75A lm75a_sensor(false,  //A0 LM75A pin state
-                   false,  //A1 LM75A pin state
-                   false); //A2 LM75A pin state
+LM75A lm75a_sensor(false,  // A0 LM75A pin state (connected to ground = false)
+                   false,  // A1 LM75A pin state (connected to ground = false)
+                   false); // A2 LM75A pin state (connected to ground = false)
 // Equivalent to "LM75A lm75a_sensor;"
 
 void setup(void)

examples/LM75A_ShowTemperature2Sensors/LM75A_ShowTemperature2Sensors.ino

@@ -0,0 +1,64 @@
+/*
+ * \brief Show temperature in degrees and fahrenheit every second from 2 different LM75A sensors on board I2C network
+ *
+ * \author Quentin Comte-Gaz <quentin@comte-gaz.com>
+ * \date 05 January 2022
+ * \license MIT License (contact me if too restrictive)
+ * \copyright Copyright (c) 2022 Quentin Comte-Gaz
+ * \version 1.2
+ */
+
+#include <LM75A.h>
+
+// Create I2C LM75A instance
+LM75A lm75a_sensor_1(false,  // A0 LM75A pin state (connected to ground = false)
+                     false,  // A1 LM75A pin state (connected to ground = false)
+                     false); // A2 LM75A pin state (connected to ground = false)
+// Equivalent to "LM75A lm75a_sensor_1;"
+
+LM75A lm75a_sensor_2(true,   // A0 LM75A pin state (connected to Vcc = true)
+                     false,  // A1 LM75A pin state (connected to ground = false)
+                     false); // A2 LM75A pin state (connected to ground = false)
+
+void setup(void)
+{
+  Serial.begin(9600);
+  Serial.println("Temperatures or 2 LM75A sensors will be displayed every second:");
+}
+
+void loop()
+{
+  // Get temperature of both sensors
+  float temperature_in_degrees_1 = lm75a_sensor_1.getTemperatureInDegrees();
+  float temperature_in_degrees_2 = lm75a_sensor_2.getTemperatureInDegrees();
+
+  // Display temperature of first sensor
+  if (temperature_in_degrees_1 == INVALID_LM75A_TEMPERATURE)
+  {
+    Serial.println("Error while getting temperature of sensor 1");
+  }
+  else
+  {
+    Serial.print("Temperature of sensor 1: ");
+    Serial.print(temperature_in_degrees_1);
+    Serial.print(" degrees (");
+    Serial.print(LM75A::degreesToFahrenheit(temperature_in_degrees_1));
+    Serial.println(" fahrenheit)");
+  }
+
+  // Display temperature of second sensor
+  if (temperature_in_degrees_2 == INVALID_LM75A_TEMPERATURE)
+  {
+    Serial.println("Error while getting temperature of sensor 2");
+  }
+  else
+  {
+    Serial.print("Temperature of sensor 2: ");
+    Serial.print(temperature_in_degrees_2);
+    Serial.print(" degrees (");
+    Serial.print(LM75A::degreesToFahrenheit(temperature_in_degrees_2));
+    Serial.println(" fahrenheit)");
+  }
+
+  delay(1000);
+}