Update comments

Add more comments to .cpp file, update README.md file and adjust keywords to #4

README.md

@@ -1,3 +1,6 @@
-# Shift-Register-74HC595-Arduino-Library
-The Shift Register 74HC595 Arduino Library makes the use of shift registers much easier.
-For detailed information visit http://shiftregister.simsso.de/.
+# ShiftRegister 74HC595 Arduino Library
+This library simplifies shift registers usage. It allows, for instance, to set shift register pins just like normal Arduino pins: `sr.set(1, HIGH)`.
+
+The **documentation** is available at http://shiftregister.simsso.de/.
+
+An **example** sketch can be found in this repository at [/examples/example/example.ino](https://github.com/Simsso/ShiftRegister74HC595/blob/master/examples/example/example.ino).

ShiftRegister74HC595.cpp

@@ -1,8 +1,15 @@
+/*
+  ShiftRegister74HC595.cpp - Library for simplified control of 74HC595 shift registers.
+  Created by Timo Denk (www.timodenk.com), Nov 2014.
+  Additional information is available at http://shiftregister.simsso.de/
+  Released into the public domain.
+*/
+
 #include "Arduino.h"
 #include "ShiftRegister74HC595.h"
 
 
-// constructor
+// ShiftRegister74HC595 constructor
 ShiftRegister74HC595::ShiftRegister74HC595(int numberOfShiftRegisters, int serialDataPin, int clockPin, int latchPin)
 {
     // set attributes
@@ -30,7 +37,10 @@ ShiftRegister74HC595::ShiftRegister74HC595(int numberOfShiftRegisters, int seria
 }
 
 
-void ShiftRegister74HC595::setAll(uint8_t * digitalValues) {
+// Set all pins of the shift registers at once.
+// digitalVAlues is a uint8_t array where the length is equal to the number of shift registers.
+void ShiftRegister74HC595::setAll(uint8_t * digitalValues)
+{
     int byte;
 
     for (byte = _numberOfShiftRegisters - 1; byte >= 0; byte--) {
@@ -44,45 +54,67 @@ void ShiftRegister74HC595::setAll(uint8_t * digitalValues) {
 }
 
 
-uint8_t * ShiftRegister74HC595::getAll() {
+// Retrieve all states of the shift registers' output pins.
+// The returned array's length is equal to the numbe of shift registers.
+uint8_t * ShiftRegister74HC595::getAll()
+{
     return _digitalValues; 
 }
 
 
-void ShiftRegister74HC595::set(int pin, uint8_t value) {
+// Set a specific pin to either HIGH (1) or LOW (0).
+// The pin parameter is a positive, zero-based integer, indicating which pin to set.
+void ShiftRegister74HC595::set(int pin, uint8_t value)
+{
     setNoUpdate(pin, value);
     updateRegisters();
 }
 
+// Updates the shift register pins to the stored output values.
 void ShiftRegister74HC595::updateRegisters()
 {
 	 setAll(_digitalValues);
 }
 
-void ShiftRegister74HC595::setNoUpdate(int pin, uint8_t value) {
-    if (value == 1)
+
+// Equivalent to set(int pin, uint8_t value), except the physical shift register is not updated.
+// Should be used in combination with updateRegisters().
+void ShiftRegister74HC595::setNoUpdate(int pin, uint8_t value)
+{
+    if (value == 1) {
         _digitalValues[pin / 8] |= 1 << (pin % 8);
-    else
+    }
+    else {
         _digitalValues[pin / 8] &= ~(1 << (pin % 8));
+    }
 }
 
 
-uint8_t ShiftRegister74HC595::get(int pin) {
+// Returns the state of the given pin.
+// Either HIGH (1) or LOW (0)
+uint8_t ShiftRegister74HC595::get(int pin)
+{
     return (_digitalValues[pin / 8] >> (pin % 8)) & 1;
 }
 
 
-void ShiftRegister74HC595::setAllHigh() {
+// Sets all pins of all shift registers to HIGH (1).
+void ShiftRegister74HC595::setAllHigh()
+{
     int i; 
-    for (i = 0; i < _numberOfShiftRegisters; i++)
+    for (i = 0; i < _numberOfShiftRegisters; i++) {
         _digitalValues[i] = 255;
+    }
     setAll(_digitalValues); 
 }
 
 
-void ShiftRegister74HC595::setAllLow() {
+// Sets all pins of all shift registers to LOW (0).
+void ShiftRegister74HC595::setAllLow()
+{
     int i; 
-    for (i = 0; i < _numberOfShiftRegisters; i++)
-        _digitalValues[i] = 0; 
+    for (i = 0; i < _numberOfShiftRegisters; i++) {
+        _digitalValues[i] = 0;
+    }
     setAll(_digitalValues); 
 }

ShiftRegister74HC595.h

@@ -1,7 +1,7 @@
 /*
-  ShiftRegister74HC595.h - Library for easy control of the 74HC595 shift register.
-  Created by Timo Denk (www.simsso.de), Nov 2014.
-  Additional information are available on http://shiftregister.simsso.de/
+  ShiftRegister74HC595.h - Library for simplified control of 74HC595 shift registers.
+  Created by Timo Denk (www.timodenk.com), Nov 2014.
+  Additional information is available at http://shiftregister.simsso.de/
   Released into the public domain.
 */
 

examples/example/example.ino

@@ -1,27 +1,30 @@
 /*
-  ShiftRegister74HC595.h - Library for easy control of the 74HC595 shift register.
-  Created by Timo Denk (www.simsso.de), Nov 2014.
-  Additional information are available on http://shiftregister.simsso.de/
+  ShiftRegister74HC595 - Library for simplified control of 74HC595 shift registers.
+  Created by Timo Denk (www.timodenk.com), Nov 2014.
+  Additional information is available at http://shiftregister.simsso.de/
   Released into the public domain.
 */
 
 #include <ShiftRegister74HC595.h>
 
-// create shift register object (number of shift registers, data pin, clock pin, latch pin)
+// create a global shift register object
+// parameters: (number of shift registers, data pin, clock pin, latch pin)
 ShiftRegister74HC595 sr (1, 0, 1, 2); 
 
 void setup() { 
 }
 
 void loop() {
 
+  // setting all pins at the same time to either HIGH or LOW
   sr.setAllHigh(); // set all pins HIGH
   delay(500);
 
   sr.setAllLow(); // set all pins LOW
   delay(500); 
 
-
+
+  // setting single pins
   for (int i = 0; i < 8; i++) {
 
     sr.set(i, HIGH); // set single pin HIGH
@@ -33,8 +36,15 @@ void loop() {
   uint8_t pinValues[] = { B10101010 }; 
   sr.setAll(pinValues); 
   delay(1000);
+
 
-  // read pin (zero based)
+  // read pin (zero based, i.e. 6th pin)
   uint8_t stateOfPin5 = sr.get(5);
-
-}
+
+
+  // set pins without immediate update
+  sr.setNoUpdate(0, HIGH);
+  sr.setNoUpdate(1, LOW);
+  // at this point of time, pin 0 and 1 did not change yet
+  sr.updateRegisters(); // update the pins to the set values
+}

keywords.txt

@@ -1,13 +1,9 @@
-ShiftRegister74HC595	KEYWORD1
-
+ShiftRegister74HC595	KEYWORD1
 setAll	KEYWORD2
-
-set	KEYWORD2
-
-setAllLow	KEYWORD2
-
-setAllHigh	KEYWORD2
-
-get	KEYWORD2
-
-getAll	KEYWORD2
+set	KEYWORD2
+setAllLow	KEYWORD2
+setAllHigh	KEYWORD2
+get	KEYWORD2
+getAll	KEYWORD2
+setNoUpdate	KEYWORD2
+updateRegisters	KEYWORDS2