Revision 0:2d50d8bba33e, committed 2015-02-23

Comitter:

okano

Date:

Mon Feb 23 06:07:04 2015 +0000

Commit message:

initial version

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/PCA9546A.cpp	Mon Feb 23 06:07:04 2015 +0000
@@ -0,0 +1,60 @@
+/**
+ *  PCA9546A library
+ *
+ *  @author  Tedd OKANO
+ *  @version 0.1
+ *  @date    Feb-2015
+ *
+ *  PCA9546A: an I2C bus switch control library
+ *
+ *  The PCA9546A is a quad bidirectional translating switch controlled 
+ *  via the I2C-bus. The SCL/SDA upstream pair fans out to four downstream 
+ *  pairs, or channels. Any individual SCx/SDx channel or combination of 
+ *  channels can be selected, determined by the contents of the programmable 
+ *  control register.
+ *
+ *  For more information about PCA9546A:
+ *    http://www.nxp.com/documents/data_sheet/PCA9546A.pdf
+ *
+ */
+
+#include "PCA9546A.h"
+
+PCA9546A::PCA9546A( PinName sda, PinName scl, char i2c_address ) 
+    : i2c_p( new I2C( sda, scl ) ), i2c( *i2c_p ), i2c_addr( i2c_address ), enable_pattern( 0x00 )
+{
+    //  do nothing.
+    //  leave it in default state.
+}
+
+PCA9546A::PCA9546A( I2C &i2c_, char i2c_address )
+    : i2c_p( NULL ), i2c( i2c_ ), i2c_addr( i2c_address ), enable_pattern( 0x00 )
+{
+    //  do nothing.
+    //  leave it in default state.
+}
+
+PCA9546A::~PCA9546A()
+{
+    if ( NULL != i2c_p )
+        delete  i2c_p;
+}
+
+void PCA9546A::on( char channel )
+{
+    enable_pattern  |= 0x1 << channel;
+
+    bitpattern( enable_pattern );
+}
+
+void PCA9546A::off( char channel )
+{
+    enable_pattern  &= ~(0x1 << channel);
+
+    bitpattern( enable_pattern );
+}
+
+void PCA9546A::bitpattern( char pattern )
+{
+    i2c.write( i2c_addr, &pattern, 1 );
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/PCA9546A.h	Mon Feb 23 06:07:04 2015 +0000
@@ -0,0 +1,132 @@
+/**
+ *  PCA9546A library
+ *
+ *  @author  Tedd OKANO
+ *  @version 0.1
+ *  @date    Feb-2015
+ *
+ *  PCA9546A: an I2C bus switch control library
+ *
+ *  The PCA9546A is a quad bidirectional translating switch controlled 
+ *  via the I2C-bus. The SCL/SDA upstream pair fans out to four downstream 
+ *  pairs, or channels. Any individual SCx/SDx channel or combination of 
+ *  channels can be selected, determined by the contents of the programmable 
+ *  control register.
+ *
+ *  For more information about PCA9546A:
+ *    http://www.nxp.com/documents/data_sheet/PCA9546A.pdf
+ *
+ */
+
+#ifndef MBED_PCA9546A_H
+#define MBED_PCA9546A_H
+
+#include "mbed.h"
+
+/** PCA9546A class
+ *
+ *  PCA9546A: an I2C bus switch control library
+ *
+ *  The PCA9546A is a quad bidirectional translating switch controlled 
+ *  via the I2C-bus. The SCL/SDA upstream pair fans out to four downstream 
+ *  pairs, or channels. Any individual SCx/SDx channel or combination of 
+ *  channels can be selected, determined by the contents of the programmable 
+ *  control register.
+ *
+ *  For more information about PCA9546A:
+ *    http://www.nxp.com/documents/data_sheet/PCA9546A.pdf
+ *
+ *  Example:
+ *  @code
+ *  #include "mbed.h"
+ *  #include "LM75B.h"
+ *  #include "PCA9546A.h"
+ *  
+ *  PCA9546A    i2c_sw( p28, p27, 0xE0 );
+ *  
+ *  int main()
+ *  {
+ *      //  all PCA9546A's downstream ports are OFF after power-up and hardware-reset
+ *      
+ *      i2c_sw.on( 0 );     //  turn-ON  the channel 0
+ *  
+ *      LM75B   tmp0( p28, p27 );   //  making instance after a branch of I2C bus (which is connecting the LM75B) enabled
+ *  
+ *      i2c_sw.off( 0 );    //  turn-OFF the channel 0
+ *      i2c_sw.on( 1 );     //  turn-ON  the channel 1
+ *  
+ *      LM75B   tmp1( p28, p27 );   //  making instance after a branch of I2C bus (which is connecting the LM75B) enabled
+ *  
+ *      while(1) {
+ *          
+ *          i2c_sw.off( 1 );    //  turn-OFF the channel 1
+ *          i2c_sw.on( 0 );     //  turn-ON  the channel 0
+ *          printf( "%.3f\r\n", tmp0.read() );
+ *  
+ *          i2c_sw.off( 0 );    //  turn-OFF the channel 0
+ *          i2c_sw.on( 1 );     //  turn-ON  the channel 1
+ *          printf( "%.3f\r\n", tmp1.read() );
+ *  
+ *          wait( 1.0 );
+ *      }
+ *  }
+ *  @endcode
+ */
+
+class PCA9546A
+{
+public:
+
+    /** Create a PCA9546A instance connected to specified I2C pins with specified address
+     *
+     * @param sda I2C-bus SDA pin
+     * @param scl I2C-bus SCL pin
+     * @param i2c_address I2C-bus address (default: 0xE0)
+     */
+    PCA9546A( PinName sda, PinName scl, char i2c_address = 0xE0 );
+
+    /** Create a PCA9546A instance connected to specified I2C pins with specified address
+     *
+     * @param &i2c_ I2C object (instance)
+     * @param i2c_address I2C-bus address (default: 0xE0)
+     */
+    PCA9546A( I2C &i2c_, char i2c_address = 0xE0 );
+
+    /** Destructor of PCA9546A
+     */
+    ~PCA9546A();
+
+    /** Turning-ON a channel
+     *
+     *  Switching a channel ON
+     *
+     * @param channel channel number
+     */
+    void on( char channel );
+
+    /** Turning-OFF a channel
+     *
+     *  Switching a channel OFF
+     *
+     * @param channel channel number
+     */
+    void off( char channel );
+
+    /** Switching by bit pattern
+     *
+     *  Switch setting by bit pattern. 
+     *  Set '1' for ON, set '0' for OFF
+     *  LSB is channel 0. Channels 1, 2 and 3 are mapped in shifted position from LSB
+     *
+     *  @param pattern ON/OFF bit pattern for channels
+     */
+    void bitpattern( char pattern );
+
+private:
+    I2C     *i2c_p;
+    I2C     &i2c;
+    char    i2c_addr;
+    char    enable_pattern;
+};
+
+#endif  //  MBED_PCA9546A_H
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