Laser Pager / Morse Code Transceiver

1//stuff for laser and photoresistor
2const int laserPin = 2;
3const  int photoPin = A0;
4const int lightLimit = 800;
5int photoVal; 
6
7//stuff  for intro
8String myName = "";
9boolean introEnd = false;
10
11//stuff for  transmitting texts
12String myText;
13String myMorse;
14String myMorseChar;
15int  myTextNum = 0;
16
17//stuff for receiving texts
18String theirMorse;
19boolean  messEnd = false;
20int spaces = 0;
21int spaceIndex;
22String theirMorseChar;
23String  theirText;
24String theirName;
25int theirTextNum = 0;
26
27//time values for  laser pulses
28const int dot = 30;
29const int dash = dot * 2;
30const int undscr  = dot * 3;
31const int elemSpace = dot;
32const int charSpace = dot;
33const  int messSpace = dot * 2;
34
35//array of Morse values in order of corresponding  ascii characters starting with space (decimal 32)
36const char* asciiArray[] =  {
37  
38// space to /
39".", "-", "_", "..", ".-", "._", "-.",  "--", "-_", "_.", "_-", "__", "...", "..-", ".._", ".-.", 
40//  0 to 9
41".--", ".-_", "._.", "._-", ".__", "-..", "-.-", "-._",  "--.", "---",
42// : to @
43"--_", "-_.", "-_-", "-__", "_..", "_.-",  "_._", 
44// A to M
45"_-.", "_--", "_-_", "__.", "__-", "___",  "....", "...-", "..._", "..-.", "..--", "..-_", ".._.", 
46// N to  Z
47".._-", "..__", ".-..", ".-.-", ".-._", ".--.", ".---", ".--_",  ".-_.", ".-_-", ".-__", "._..", "._.-", 
48// [ to `
49"._._", "._-.",  "._--", "._-_", ".__.", ".__-",
50// a to m
51".___", "-...", "-..-",  "-.._", "-.-.", "-.--", "-.-_", "-._.", "-._-", "-.__", "--..",  "--.-", "--._", 
52// n to z
53"---.", "----", "---_", "--_.", "--_-",  "--__", "-_..", "-_.-", "-_._", "-_-.", "-_--", "-_-_", "-__.",  
54// { to ~
55"-__-", "-___", "_...", "_..-" 
56};
57
58void setup()  {
59  //initialize and turn on laser 
60  pinMode(laserPin, OUTPUT);
61  digitalWrite(laserPin,  HIGH);
62
63  //set Serial and print instructions
64  Serial.begin(9600);
65  Serial.println(F("Align the laser and sensor with another user's, then enter  a username."));
66}
67
68void loop() {
69  //intro keeps laser on until username  input
70  while(introEnd == false) {
71    
72    //when user sends something  to Serial
73    if(Serial.available()>0) {
74      
75      //new myName from  Serial has leading and trailing whitespace removed
76      myName = Serial.readString();
77      myName.trim();
78    }
79    
80    //when myName value has changed
81    if(myName != "") { 
82      
83      //turn off laser and allow next while  loop
84      digitalWrite(laserPin, LOW);
85      introEnd = true;
86      
87      //intro message with separating line
88      Serial.print(F("Hi, "));
89      Serial.print(myName);
90      Serial.println(F("! Message away."));
91      Serial.print(F("─────────────────────────────────────────────────────────"));
92      Serial.println(F("────────────────────────────────────────────────────────"));
93    }
94  }
95  
96  //the meat and potatoes if yknow what I mean
97  while(introEnd  == true) {
98      
99    //transmitter loop starting when Serial gets something
100    while(Serial.available() > 0) {
101      
102      //prints text sent to Serial  for self
103      myText = Serial.readString();
104      myText.trim();
105      Serial.print(F("Me:  "));
106      Serial.println(myText);
107      Serial.println();
108
109      //turns  myName into sending format
110      myName += ": ";
111    
112      //only sends  username in first message, shortens time for subsequent messages
113      if(myTextNum  == 0) {
114        myText = myName + myText;
115      }
116      
117      //loop  for constructing Morse code from myText
118      for(int i=0; i < myText.length();  i++) {
119       
120        //subtract ascii value of each char in myMorseName  by 32 for place in array and adds thus Morse to myMorse separated by spaces
121        myMorseChar = asciiArray[myText.charAt(i) - 32];
122        myMorse += myMorseChar  + " ";
123      }
124    
125      //converts Morse characters to laser pulses
126      for(int i=0; i < myMorse.length(); i++) {
127        
128        //repurposes  myMorseChar for individual Morse elements
129        myMorseChar = myMorse.charAt(i);
130        
131        //if character is a dot
132        if(myMorseChar == ".")  {
133          digitalWrite(laserPin, HIGH);
134          delay(dot);
135        }
136        //if character is a dash
137        else if(myMorseChar == "-") {
138          digitalWrite(laserPin, HIGH);
139          delay(dash);
140        }
141        //if character is an underscore
142        else if(myMorseChar == "_")  {
143          digitalWrite(laserPin, HIGH);
144          delay(undscr);
145        }
146        //if character is a space
147        else if(myMorseChar == " ") {
148          delay(charSpace);
149        }
150        //space between elements
151        digitalWrite(laserPin, LOW);
152        delay(elemSpace);
153      }
154
155      //clear myMorse, add 1 to sent message total and delay before next message
156      myMorse = "";
157      myTextNum++;
158      delay(messSpace);
159    }
160    
161    //receiver loop starting when laser brightness detected
162    while(analogRead(photoPin)  > lightLimit) {
163
164      //reset boolean for ending Morse retrieval loop and  delay by dot length + 5
165      messEnd = false;
166      delay(dot + 5);
167      
168      //loop for getting Morse characters, starts when dot would end and ends when  time off is longer than space pause
169      while(messEnd == false) {
170    
171        //delay for dot time and add dot if laser is off by then, otherwise go to  dash/undscr
172        if(analogRead(photoPin) < lightLimit) {
173          theirMorse  += ".";
174        }
175        //delay for additional dot, add dash if off by  then, otherwise add undscr and delay for another dot
176        else {
177          delay(dash  - dot);
178          if(analogRead(photoPin) < lightLimit) {
179            theirMorse  += "-";
180          }
181          else {
182            theirMorse += "_";
183            delay(undscr - dash);
184          }
185        }
186        //delay  by element space for next element
187        delay(elemSpace);
188
189        //if  laser is not back on after element space, delay and add dash space
190        if(analogRead(photoPin)  < lightLimit) {
191          delay(charSpace + elemSpace);
192          theirMorse  += " ";
193          
194          //delay by dot if laser is back on, otherwise  end loop
195          if(analogRead(photoPin) < lightLimit) {
196            delay(dot);
197          }
198          else {
199            messEnd = true;
200          }
201        }
202        //if laser is back on after element space, delay and restart  loop
203        else {
204          delay(dot);
205        }
206      }
207       
208      //count spaces in theirMorse to make size of spaceIndexArray
209      for(int  i=0; i <= 95; i++) {
210        if(theirMorse[i] == ' ') {
211          spaces++;
212        }
213      }
214      int spaceIndexArray[spaces];
215      
216      //find  positions of spaces in theirMorse and add to spaceIndexArray
217      for(int i=0;  i <= spaces; i++) {
218        if(i == 0) {
219          spaceIndexArray[i] = theirMorse.indexOf('  ');
220        }
221        else {
222          spaceIndexArray[i] = theirMorse.indexOf('  ', spaceIndexArray[i - 1] + 1);
223        }
224      }
225
226      //extract Morse  chars with substrings starting after previous space and ending on current space
227      for(int i=0; i <= spaces; i++) {
228        if(i == 0) {
229          theirMorseChar  = theirMorse.substring(0, spaceIndexArray[i]);
230        }
231        else {
232          theirMorseChar = theirMorse.substring(spaceIndexArray[i - 1] + 1, spaceIndexArray[i]);
233        }
234
235        //find theirMorseChar in asciiArray and add corresponding  char to theirText
236        for(int j=0; j <= 95; j++) {
237          if(theirMorseChar  == asciiArray[j]) {
238            theirText += char (j + 32);
239          }
240        }
241      }
242
243      //trim theirText and only register message if  it is not blank
244      theirText.trim();
245      if(theirText.length() > 0) {
246        
247        //if this is the first received message, print text normally
248        if(theirTextNum == 0) {
249          Serial.println(theirText);
250          Serial.println();
251
252          //extract username with substring ending after first colon
253          theirName  = theirText.substring(0, theirText.indexOf(": ") + 2);
254        }
255
256        //after  first message, print name and new text
257        else {
258          Serial.print(theirName);
259          Serial.println(theirText);
260          Serial.println();
261        }
262
263        //add 1 to received message total
264        theirTextNum++;
265      }
266      
267      //reset theirMorse, spaces and theirText
268      theirMorse = "";
269      spaces = 0;
270      theirText = "";
271    }
272  }
273}