Revision 2:6c22af0aafbb, committed 2016-11-10

Comitter:

jolyon

Date:

Thu Nov 10 16:56:33 2016 +0000

Parent:

1:ec8da0c59403

Commit message:

If device does not ack the return data is 0

Changed in this revision

diff -r ec8da0c59403 -r 6c22af0aafbb PCF8574.cpp
--- a/PCF8574.cpp	Thu Jun 03 13:00:49 2010 +0000
+++ b/PCF8574.cpp	Thu Nov 10 16:56:33 2016 +0000
@@ -23,19 +23,26 @@
 #include "PCF8574.h"
 #include "mbed.h"
 
-PCF8574::PCF8574(PinName sda, PinName scl, int address)
+JPCF8574::JPCF8574(PinName sda, PinName scl, int address)
         : _i2c(sda, scl) {
     _address = address;
 }
 
-int PCF8574::read() {
+int JPCF8574::read() {
     char foo[1];
-    _i2c.read(_address, foo, 1);
+    char Error = 0;
+    Error = _i2c.read(_address, foo, 1);
+    if (Error == 1)
+    {
+        foo[0] = 0;    
+    }
+
     return foo[0];
 }
 
-void PCF8574::write(int data) {
+void JPCF8574::write(int data) {
     char foo[1];
     foo[0] = data;
     _i2c.write(_address, foo, 1);
 }
+

diff -r ec8da0c59403 -r 6c22af0aafbb PCF8574.h
--- a/PCF8574.h	Thu Jun 03 13:00:49 2010 +0000
+++ b/PCF8574.h	Thu Nov 10 16:56:33 2016 +0000
@@ -26,7 +26,7 @@
 #define MBED_PCF8574_H
 
 /** Interface to the popular PCF8574 I2C 8 Bit IO expander */
-class PCF8574 {
+class JPCF8574 {
 public:
     /** Create an instance of the PCF8574 connected to specfied I2C pins, with the specified address.
      *
@@ -34,7 +34,7 @@
      * @param scl The I2C clock pin
      * @param address The I2C address for this PCF8574
      */
-    PCF8574(PinName sda, PinName scl, int address);
+    JPCF8574(PinName sda, PinName scl, int address);
 
     /** Read the IO pin level
      *