Added setting I2C bus speed

Issue #3
Zanduino · Jun 30, 2018 · 6b4ed0c · 6b4ed0c
1 parent 0265ba6
commit 6b4ed0c
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Showing 2 changed files with 6 additions and 2 deletions.
diff --git a/src/DS3231M.cpp b/src/DS3231M.cpp
@@ -181,8 +181,9 @@ DS3231M_Class::~DS3231M_Class() {}                                            //
 ** Method begin starts I2C communications with the device, using a default address if one is not specified and    **
 ** return true if the device has been detected and false if it was not                                            **
 *******************************************************************************************************************/
-bool DS3231M_Class::begin() {                                                 // Start I2C communications         //
+bool DS3231M_Class::begin(const uint16_t i2cSpeed) {                          // Start I2C communications         //
   Wire.begin();                                                               // Start I2C as master device       //
+  Wire.setClock(i2cSpeed);                                                    // Set I2C clock speed              //
   Wire.beginTransmission(DS3231M_ADDRESS);                                    // Address the DS3231M              //
   uint8_t errorCode = Wire.endTransmission();                                 // See if there's a device present  //
   if (errorCode == 0) {                                                       // If we have a DS3231M             //

diff --git a/src/DS3231M.h b/src/DS3231M.h
@@ -23,6 +23,7 @@
 **                                                                                                                **
 ** Vers.  Date       Developer                         Comments                                                   **
 ** ====== ========== ================================= ========================================================== **
+** 1.0.2  2018-06-30 https://github.com/SV-Zanshin     Issue #3 - Allow 400KHz I2C bus speed to be set            **
 ** 1.0.0  2017-08-19 https://github.com/SV-Zanshin     Initial release                                            **
 ** 1.0.0b 2017-08-13 https://github.com/SV-Zanshin     Initial coding                                             **
 **                                                                                                                **
@@ -45,6 +46,8 @@
   /*****************************************************************************************************************
   ** Declare constants used in the class                                                                          **
   *****************************************************************************************************************/
+  const uint16_t I2C_STANDARD_MODE         =    100000;                       // Default normal I2C comms speed   //
+  const uint16_t I2C_FAST_MODE             =    400000;                       // Fast mode                        //
   const uint32_t SECONDS_PER_DAY           =     86400;                       // 60 secs * 60 mins * 24 hours     //
   const uint32_t SECONDS_FROM_1970_TO_2000 = 946684800;                       //                                  //
   const uint8_t  DS3231M_ADDRESS           =      0x68;                       // Fixed I2C Address for DS3231M    //
@@ -120,7 +123,7 @@
     public:                                                                   // Publicly visible methods         //
       DS3231M_Class();                                                        // Class constructor                //
       ~DS3231M_Class();                                                       // Class destructor                 //
-      bool     begin();                                                       // Start I2C Communications         //
+      bool     begin(const uint16_t i2cSpeed = I2C_STANDARD_MODE);            // Start I2C Communications         //
       void     adjust();                                                      // Set the date and time to compile //
       void     adjust(const DateTime& dt);                                    // Set the date and time            //
       DateTime now();                                                         // return time                      //