HelloWorld program for PCA9547: an I2C bus multiplexer control library. PCA9547 is an I2C multiplexer which enables to select 1:8 multiplexed I2C bus. The multiplexer is useful for deviding I2C bus to avoiding slave address conflict and separating capacitive loads. For more information about PCA9547: http://www.nxp.com/documents/data_sheet/PCA9547.pdf

Dependencies:   LM75B PCA9547 mbed

What is this?

This is a sample code to demonstrate the PCA9547. The PCA9547 is a 8 channel multiplexer for I2C bus.
The code shows how the bed can access the I2C device (LM75B) through PCA9547.

PCA9547_and_LM75B
Demo hardware block diagram

/media/uploads/okano/pca9547_connections.png
Connection between mbed and PCA9547

Information

For more information, please visit component page.

The PCA9547 is an octal bidirectional translating multiplexer controlled by the I2C-bus. The SCL/SDA upstream pair fans out to eight downstream pairs, or channels.

Revision:
1:63d8f8d68f61
Parent:
0:fb906b7b1452
Child:
2:63d9012f8c01
Child:
3:e8697f8b6da5
--- a/main.cpp	Mon Jun 30 23:57:31 2014 +0000
+++ b/main.cpp	Tue Jul 01 00:10:44 2014 +0000
@@ -1,19 +1,13 @@
 #include "mbed.h"
 #include "LM75B.h"
-
-
-I2C     i2c( p28, p27 );
-
-void set_pca9547( char ch )
-{
-    char    v   = 0x08 | ch;
-    i2c.write( 0xE0, &v, 1 );
-}
+#include "PCA9547.h"
 
 int main()
 {
-    set_pca9547( 0 );
-
+    PCA9547 mux( p28, p27, 0xE0 );
+    
+    mux.select( 0 );
+    
     LM75B   tmp0( p28, p27 );   //  making instance after a branch of I2C bus (which is connecting the LM75B) enabled
 
     while(1) {