[RTTY] String encoding based on number of data bits

examples/SX127x_RTTY_Transmit/SX127x_RTTY_Transmit.ino

@@ -48,9 +48,9 @@ void setup() {
   // low frequency:               434.0 MHz
   // frequency shift:             183 Hz
   // baud rate:                   45 baud
-  // data bits:                   8
+  // data bits:                   8 (ASCII encoding)
   // stop bits:                   1
-  state = rtty.begin(434, 183, 45, 5);
+  state = rtty.begin(434, 183, 45, 8);
   if(state == ERR_NONE) {
     Serial.println(F("success!"));
   } else {
@@ -94,21 +94,27 @@ void loop() {
 
   /*
     // KiteLib also provides ITA2 ("Baudot") code support
-    // RTTY client must be configured to 5 bits
+    // To enable ITA2 encoding, set RTTY client
+    // to 5 data bits
     rtty.begin(434, 183, 45, 5);
 
     // send synchronization string ("RYRY..." corresponds
     // to binary 01010101010101010101... in ITA2 encoding)
-    ITA2 sync = "RYRYRYRY";
+    rtty.println("RYRYRYRY");
-    rtty.println(sync);
 
-    // create ITA2-encoded string
+    // send ITA2-encoded string (all ASCII characters
-    // NOTE: ASCII characters that do not have ITA2
+    // that do not have ITA2 equivalent will be replaced
-    //       equivalent will be replaced with NUL
+    // with NUL
-    ITA2 itaStr = "HELLO WORLD";
+    rtty.println("HELLO WORLD!");
 
-    // print the ITA2 string
+    String aStr = "ARDUINO STRING";
-    rtty.println(itaStr);
+    rtty.println(aStr);
+  
+    // character array (C-string)
+    rtty.println("C-STRING");
+  
+    // character
+    rtty.println('C');
 
     // all numbers can also be sent using ITA2
     float f = -3.1415;

src/protocols/RTTY.cpp

@@ -1,5 +1,11 @@
 #include "RTTY.h"
 
+ITA2::ITA2(char c) {
+  _len = 1;
+  _str = new char[1];
+  _str[0] = c;
+}
+
 ITA2::ITA2(const char* str) {
   _len = strlen(str);
   _str = new char[_len];
@@ -147,15 +153,36 @@ size_t RTTYClient::print(ITA2& ita2) {
 }
 
 size_t RTTYClient::print(const String& str) {
-  return(RTTYClient::write((uint8_t*)str.c_str(), str.length()));
+  size_t n = 0;
+  if(_dataBits == 5) {
+    ITA2 ita2 = str.c_str();
+    n = RTTYClient::print(ita2);
+  } else {
+    n = RTTYClient::write((uint8_t*)str.c_str(), str.length());
+  }
+  return(n);
 }
 
 size_t RTTYClient::print(const char str[]) {
-  return(RTTYClient::write((uint8_t*)str, strlen(str)));
+  size_t n = 0;
+  if(_dataBits == 5) {
+    ITA2 ita2 = str;
+    n = RTTYClient::print(ita2);
+  } else {
+    n = RTTYClient::write((uint8_t*)str, strlen(str));
+  }
+  return(n);
 }
 
 size_t RTTYClient::print(char c) {
-  return(RTTYClient::write(c));
+  size_t n = 0;
+  if(_dataBits == 5) {
+    ITA2 ita2 = c;
+    n = RTTYClient::print(ita2);
+  } else {
+    n = RTTYClient::write(c);
+  }
+  return(n);
 }
 
 size_t RTTYClient::print(unsigned char b, int base) {

src/protocols/RTTY.h

@@ -18,6 +18,7 @@ const char ITA2Table[ITA2_LENGTH][2] = {{'\0', '\0'}, {'E', '3'}, {'\n', '\n'},
 
 class ITA2 {
   public:
+    ITA2(char c);
     ITA2(const char* str);
     ~ITA2();