Diff: MMA8452.cpp

Revision:

6:f6bde04bf8be

Parent:

5:b3d0abd97e55

Child:

8:89272163f395

--- a/MMA8452.cpp	Wed Oct 16 18:55:16 2013 +0000
+++ b/MMA8452.cpp	Thu Oct 17 09:41:35 2013 +0000
@@ -19,20 +19,19 @@
 
 # include "MMA8452.h"
 
-
-
-
-
-
 // Connect module at I2C address using I2C port pins sda and scl
 Accelerometer_MMA8452::Accelerometer_MMA8452(PinName sda, PinName scl,int frequency) : m_i2c(sda, scl) , m_frequency(frequency)
 {
     //m_i2c.frequency(m_frequency);
+    
+    // setup read and write addresses to avoid duplication
+   _readAddress   = (MMA8452_ADDRESS<<1) | 0x01;
+   _writeAddress  = (MMA8452_ADDRESS<<1) & 0xFE;
 }
 
 
 // Destroys instance
-Accelerometer_MMA8452::~Accelerometer_MMA8452()
+Accelerometer_MMA8452::~Accelerometer_MMA8452() 
 {
 
 }
@@ -40,32 +39,22 @@
 // Setting the control register bit 1 to true to activate the MMA8452
 int Accelerometer_MMA8452::activate()
 {
-    char mcu_address = (MMA8452_ADDRESS<<1);
-    char init[2];
-    init[0] = CTRL_REG_1;                 // control register 1
-    init[1] = ACTIVE;                     // set to active
+    // set control register 1 to active
+    char init[2] = {CTRL_REG_1,ACTIVE};
     
-    if(m_i2c.write(mcu_address,init,2) == 0)
-    {
-         return 0;  // return 0 to indicate success
-    }
-    else
-    {
-        return 1;   // crumbs it failed!!!
-    }
-         
+    // perform write and return error code
+    return m_i2c.write(_writeAddress,init,2);
 }
 
 
 // Get 'Fast Read Mode' called F_READ. If bit 1 is set '1' then F_READ is active. Fast read will skip LSB when reading xyz
 // resisters from 0x01 to 0x06. When F_READ is '0' then all 6 registers will be read.
 
-int Accelerometer_MMA8452::get_CTRL_Reg1(int& CTRL_Reg)
-{
+int Accelerometer_MMA8452::get_CTRL_Reg1(int* CTRL_Reg)
 {
     char mcu_address = (MMA8452_ADDRESS<<1);
     m_i2c.start();
-    if( m_i2c.write( mcu_address & 0xFE) == 0)          // just good practice to force bit 1 to a '0' by ANDing with 0xFE
+    if( m_i2c.write(_writeAddress) == 0)
     {
         return 1;                                       // we failed to write the mcu address on the bus to initiate dialogue 
     }
@@ -78,16 +67,9 @@
     {
         return 1;                                       // we failed to request a read from that mcu - this really is just writing the mcu vaule on the bus
     }
-    CTRL_Reg  = m_i2c.read(0);
+    *CTRL_Reg  = m_i2c.read(0);
     m_i2c.stop();
     return 0;
-    
-
-}
-
-
-
-
 }
 
 // Setting the control register bit 1 to true to activate the MMA8452