+ 0.1.05

+ added rotate left and right
+ toggle mask to toggle multiple bits in one write.
+ refactor (after CPPcheck)

libraries/PCF8574/PCF8574.cpp

@@ -2,11 +2,12 @@
 //    FILE: PCF8574.cpp
 //  AUTHOR: Rob Tillaart
 //    DATE: 02-febr-2013
-// VERSION: 0.1.04
+// VERSION: 0.1.05
 // PURPOSE: I2C PCF8574 library for Arduino
 //     URL:
 //
 // HISTORY:
+// 0.1.05 2016-04-30 refactor, +toggleMask, +rotLeft, +rotRight
 // 0.1.04 2015-05-09 removed ambiguity in read8()
 // 0.1.03 2015-03-02 address int -> uint8_t
 // 0.1.02 replaced ints with uint8_t to reduce footprint;
@@ -21,11 +22,13 @@
 
 #include <Wire.h>
 
-PCF8574::PCF8574(uint8_t deviceAddress)
+PCF8574::PCF8574(const uint8_t deviceAddress)
 {
     _address = deviceAddress;
     Wire.begin();
     // TWBR = 12; // 400KHz
+    _data = 0;
+    _error = 0;
 }
 
 // removed Wire.beginTransmission(addr);
@@ -48,12 +51,8 @@ uint8_t PCF8574::read8()
     return _data;
 }
 
-uint8_t PCF8574::value()
-{
-    return _data;
-}
 
-void PCF8574::write8(uint8_t value)
+void PCF8574::write8(const uint8_t value)
 {
     _data = value;
     Wire.beginTransmission(_address);
@@ -62,37 +61,44 @@ void PCF8574::write8(uint8_t value)
 }
 
 // pin should be 0..7
-uint8_t PCF8574::read(uint8_t pin)
+uint8_t PCF8574::read(const uint8_t pin)
 {
     PCF8574::read8();
-    return (_data & (1<<pin)) > 0;
+    return (_data & (1 << pin)) > 0;
 }
 
 // pin should be 0..7
-void PCF8574::write(uint8_t pin, uint8_t value)
+void PCF8574::write(const uint8_t pin, const uint8_t value)
 {
     PCF8574::read8();
     if (value == LOW)
     {
-        _data &= ~(1<<pin);
+        _data &= ~(1 << pin);
     }
     else
     {
-        _data |= (1<<pin);
+        _data |= (1 << pin);
     }
     PCF8574::write8(_data);
 }
 
 // pin should be 0..7
-void PCF8574::toggle(uint8_t pin)
+void PCF8574::toggle(const uint8_t pin)
+{
+    if (pin > 7 ) return;
+    toggleMask(1 << pin);
+}
+
+// invert = toggleAll = toggleMask(0xFF)
+void PCF8574::toggleMask(const uint8_t mask)
 {
     PCF8574::read8();
-    _data ^=  (1 << pin);
+    _data ^= mask;
     PCF8574::write8(_data);
 }
 
 // n should be 0..7
-void PCF8574::shiftRight(uint8_t n)
+void PCF8574::shiftRight(const uint8_t n)
 {
     if (n == 0 || n > 7 ) return;
     PCF8574::read8();
@@ -101,7 +107,7 @@ void PCF8574::shiftRight(uint8_t n)
 }
 
 // n should be 0..7
-void PCF8574::shiftLeft(uint8_t n)
+void PCF8574::shiftLeft(const uint8_t n)
 {
     if (n == 0 || n > 7) return;
     PCF8574::read8();
@@ -115,6 +121,23 @@ int PCF8574::lastError()
     _error = 0;
     return e;
 }
+
+// n should be 0..7
+void PCF8574::rotateRight(const uint8_t n)
+{
+    if (n == 0 || n > 7 ) return;
+    PCF8574::read8();
+    _data = (_data >> n) | (_data << (8-n));
+    PCF8574::write8(_data);
+}
+
+// n should be 0..7
+void PCF8574::rotateLeft(const uint8_t n)
+{
+    rotateRight(8-n);
+}
+
+
 //
 // END OF FILE
 //

libraries/PCF8574/PCF8574.h

@@ -2,7 +2,7 @@
 //    FILE: PCF8574.H
 //  AUTHOR: Rob Tillaart
 //    DATE: 02-febr-2013
-// VERSION: 0.1.04
+// VERSION: 0.1.05
 // PURPOSE: I2C PCF8574 library for Arduino
 //     URL:
 //
@@ -19,23 +19,29 @@
 #include "WProgram.h"
 #endif
 
-#define PCF8574_LIB_VERSION "0.1.04"
+#define PCF8574_LIB_VERSION "0.1.05"
 
 class PCF8574
 {
 public:
-    PCF8574(uint8_t deviceAddress);
+    explicit PCF8574(const uint8_t deviceAddress);
 
     uint8_t read8();
     uint8_t read(uint8_t pin);
-    uint8_t value();
 
-    void write8(uint8_t value);
-    void write(uint8_t pin, uint8_t value);
+    uint8_t value() const { return _data; };
 
-    void toggle(uint8_t pin);
-    void shiftRight(uint8_t n=1);
-    void shiftLeft(uint8_t n=1);
+    void write8(const uint8_t value);
+    void write(const uint8_t pin, const uint8_t value);
+
+    void toggle(const uint8_t pin);
+    void toggleMask(const uint8_t mask);
+
+    void shiftRight(const uint8_t n=1);
+    void shiftLeft(const uint8_t n=1);
+
+    void rotateRight(const uint8_t n=1);
+    void rotateLeft(const uint8_t n=1);
 
     int lastError();
 

libraries/PCF8574/examples/PCF8574_test2/PCF8574_test2.ino

@@ -0,0 +1,58 @@
+//
+//    FILE: pcf8574_test2.ino
+//  AUTHOR: Rob Tillaart
+//    DATE: 2016-04-30
+//
+// PUPROSE: demo rotateLeft, -Right and toggleMask
+//
+
+#include "PCF8574.h"
+#include <Wire.h>
+
+// adjust addresses if needed
+PCF8574 PCF_39(0x39);  // add leds to lines      (used as output)
+
+void setup()
+{
+    Serial.begin(115200);
+    Serial.print("\npcf8574_test2.ino\nlib version: ");
+    Serial.println(PCF8574_LIB_VERSION);
+
+    PCF_39.write(0, 1);
+    for (int i=0; i<7; i++)
+    {
+        PCF_39.rotateLeft();
+        delay(100);
+    }
+
+    for (int i=0; i<7; i++)
+    {
+        PCF_39.rotateRight();
+        delay(100);
+    }
+
+    for (int i=0; i<7; i++)
+    {
+        PCF_39.rotateLeft(3);
+        delay(100);
+    }
+
+    for (int i=0; i<7; i++)
+    {
+        PCF_39.rotateRight(2);
+        delay(100);
+    }
+
+    for (int i=0; i<255; i++)
+    {
+        PCF_39.toggleMask(i);
+        delay(100);
+    }
+}
+
+void loop()
+{
+}
+//
+// END OF FILE
+//