Add a bunch of const qualifiers

These help to catch bugs, and also can sometimes help the compiler
optimize the code

RCSwitch.cpp

@@ -189,26 +189,26 @@ void RCSwitch::switchOff(int nAddressCode, int nChannelCode) {
 }
 
 /**
- * Deprecated, use switchOn(char* sGroup, char* sDevice) instead!
+ * Deprecated, use switchOn(const char* sGroup, const char* sDevice) instead!
  * Switch a remote switch on (Type A with 10 pole DIP switches)
  *
  * @param sGroup        Code of the switch group (refers to DIP switches 1..5 where "1" = on and "0" = off, if all DIP switches are on it's "11111")
  * @param nChannelCode  Number of the switch itself (1..5)
  */
-void RCSwitch::switchOn(char* sGroup, int nChannel) {
-  char* code[6] = { "00000", "10000", "01000", "00100", "00010", "00001" };
+void RCSwitch::switchOn(const char* sGroup, int nChannel) {
+  const char* code[6] = { "00000", "10000", "01000", "00100", "00010", "00001" };
   this->switchOn(sGroup, code[nChannel]);
 }
 
 /**
- * Deprecated, use switchOff(char* sGroup, char* sDevice) instead!
+ * Deprecated, use switchOff(const char* sGroup, const char* sDevice) instead!
  * Switch a remote switch off (Type A with 10 pole DIP switches)
  *
  * @param sGroup        Code of the switch group (refers to DIP switches 1..5 where "1" = on and "0" = off, if all DIP switches are on it's "11111")
  * @param nChannelCode  Number of the switch itself (1..5)
  */
-void RCSwitch::switchOff(char* sGroup, int nChannel) {
-  char* code[6] = { "00000", "10000", "01000", "00100", "00010", "00001" };
+void RCSwitch::switchOff(const char* sGroup, int nChannel) {
+  const char* code[6] = { "00000", "10000", "01000", "00100", "00010", "00001" };
   this->switchOff(sGroup, code[nChannel]);
 }
 
@@ -218,7 +218,7 @@ void RCSwitch::switchOff(char* sGroup, int nChannel) {
  * @param sGroup        Code of the switch group (refers to DIP switches 1..5 where "1" = on and "0" = off, if all DIP switches are on it's "11111")
  * @param sDevice       Code of the switch device (refers to DIP switches 6..10 (A..E) where "1" = on and "0" = off, if all DIP switches are on it's "11111")
  */
-void RCSwitch::switchOn(char* sGroup, char* sDevice) {
+void RCSwitch::switchOn(const char* sGroup, const char* sDevice) {
     this->sendTriState( this->getCodeWordA(sGroup, sDevice, true) );
 }
 
@@ -228,7 +228,7 @@ void RCSwitch::switchOn(char* sGroup, char* sDevice) {
  * @param sGroup        Code of the switch group (refers to DIP switches 1..5 where "1" = on and "0" = off, if all DIP switches are on it's "11111")
  * @param sDevice       Code of the switch device (refers to DIP switches 6..10 (A..E) where "1" = on and "0" = off, if all DIP switches are on it's "11111")
  */
-void RCSwitch::switchOff(char* sGroup, char* sDevice) {
+void RCSwitch::switchOff(const char* sGroup, const char* sDevice) {
     this->sendTriState( this->getCodeWordA(sGroup, sDevice, false) );
 }
 
@@ -252,7 +252,7 @@ char* RCSwitch::getCodeWordB(int nAddressCode, int nChannelCode, boolean bStatus
    int nReturnPos = 0;
    static char sReturn[13];
    
-   char* code[5] = { "FFFF", "0FFF", "F0FF", "FF0F", "FFF0" };
+   const char* code[5] = { "FFFF", "0FFF", "F0FF", "FF0F", "FFF0" };
    if (nAddressCode < 1 || nAddressCode > 4 || nChannelCode < 1 || nChannelCode > 4) {
     return '\0';
    }
@@ -282,10 +282,8 @@ char* RCSwitch::getCodeWordB(int nAddressCode, int nChannelCode, boolean bStatus
 /**
  * Returns a char[13], representing the Code Word to be send.
  *
- * getCodeWordA(char*, char*)
- *
  */
-char* RCSwitch::getCodeWordA(char* sGroup, char* sDevice, boolean bOn) {
+char* RCSwitch::getCodeWordA(const char* sGroup, const char* sDevice, boolean bOn) {
     static char sDipSwitches[13];
     int i = 0;
     int j = 0;
@@ -330,8 +328,8 @@ char* RCSwitch::getCodeWordC(char sFamily, int nGroup, int nDevice, boolean bSta
     return '\0';
   }
   
-  char* sDeviceGroupCode =  dec2binWzerofill(  (nDevice-1) + (nGroup-1)*4, 4  );
-  char familycode[16][5] = { "0000", "F000", "0F00", "FF00", "00F0", "F0F0", "0FF0", "FFF0", "000F", "F00F", "0F0F", "FF0F", "00FF", "F0FF", "0FFF", "FFFF" };
+  const char* sDeviceGroupCode =  dec2binWzerofill(  (nDevice-1) + (nGroup-1)*4, 4  );
+  const char familycode[16][5] = { "0000", "F000", "0F00", "FF00", "00F0", "F0F0", "0FF0", "FFF0", "000F", "F00F", "0F0F", "FF0F", "00FF", "F0FF", "0FFF", "FFFF" };
   for (int i = 0; i<4; i++) {
     sReturn[nReturnPos++] = familycode[ (int)sFamily - 97 ][i];
   }
@@ -437,7 +435,7 @@ char* RCSwitch::getCodeWordD(char sGroup, int nDevice, boolean bStatus){
 /**
  * @param sCodeWord   /^[10FS]*$/  -> see getCodeWord
  */
-void RCSwitch::sendTriState(char* sCodeWord) {
+void RCSwitch::sendTriState(const char* sCodeWord) {
   for (int nRepeat=0; nRepeat<nRepeatTransmit; nRepeat++) {
     int i = 0;
     while (sCodeWord[i] != '\0') {
@@ -462,7 +460,7 @@ void RCSwitch::send(unsigned long Code, unsigned int length) {
   this->send( this->dec2binWzerofill(Code, length) );
 }
 
-void RCSwitch::send(char* sCodeWord) {
+void RCSwitch::send(const char* sCodeWord) {
   for (int nRepeat=0; nRepeat<nRepeatTransmit; nRepeat++) {
     int i = 0;
     while (sCodeWord[i] != '\0') {

RCSwitch.h

@@ -60,18 +60,18 @@ class RCSwitch {
     
     void switchOn(int nGroupNumber, int nSwitchNumber);
     void switchOff(int nGroupNumber, int nSwitchNumber);
-    void switchOn(char* sGroup, int nSwitchNumber);
-    void switchOff(char* sGroup, int nSwitchNumber);
+    void switchOn(const char* sGroup, int nSwitchNumber);
+    void switchOff(const char* sGroup, int nSwitchNumber);
     void switchOn(char sFamily, int nGroup, int nDevice);
     void switchOff(char sFamily, int nGroup, int nDevice);
-    void switchOn(char* sGroup, char* sDevice);
-    void switchOff(char* sGroup, char* sDevice);
+    void switchOn(const char* sGroup, const char* sDevice);
+    void switchOff(const char* sGroup, const char* sDevice);
     void switchOn(char sGroup, int nDevice);
     void switchOff(char sGroup, int nDevice);
 
-    void sendTriState(char* Code);
+    void sendTriState(const char* Code);
     void send(unsigned long Code, unsigned int length);
-    void send(char* Code);
+    void send(const char* Code);
     
     #if not defined( RCSwitchDisableReceiving )
     void enableReceive(int interrupt);
@@ -99,8 +99,8 @@ class RCSwitch {
   
   private:
     char* getCodeWordB(int nGroupNumber, int nSwitchNumber, boolean bStatus);
-    char* getCodeWordA(char* sGroup, int nSwitchNumber, boolean bStatus);
-    char* getCodeWordA(char* sGroup, char* sDevice, boolean bStatus);
+    char* getCodeWordA(const char* sGroup, int nSwitchNumber, boolean bStatus);
+    char* getCodeWordA(const char* sGroup, const char* sDevice, boolean bStatus);
     char* getCodeWordC(char sFamily, int nGroup, int nDevice, boolean bStatus);
     char* getCodeWordD(char group, int nDevice, boolean bStatus);
     void sendT0();