Stoil Ivanov / LaserCommProtocol_01

Laser Communication Protocol developed during HEPTA-Sat training in Bulgaria, October 2017.

Dependencies:   Hepta9axis HeptaBattery HeptaCamera_GPS HeptaTemp HeptaXbee SDFileSystem mbed

3daf572bcae1/main.cpp@1:f7206e74c970, 2017-11-17 (annotated)

Committer:
stoilivanov
Date:
Fri Nov 17 14:17:20 2017 +0000
Revision:
1:f7206e74c970
Parent:
0:95bf84c286f5 
Submission from a team (Ivan Mihov, Stoil Ivanov, Zdravko Dimitrov) in HEPTA-Sat training, Bulgaria.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
stoilivanov 1:f7206e74c970 1 /*This is the RECEIVER code of Laser Communication Protocol v1.0 developed by
stoilivanov 1:f7206e74c970 2 Ivan Mihov, Stoil Ivanov and Zdravko Dimitrov. The protocol was developed during
stoilivanov 1:f7206e74c970 3 the HEPTA-Sat training held in the Faculty of Physics at Sofia University
stoilivanov 1:f7206e74c970 4 "St. Kliment Ohridski", Bulgaria. The training was conducted from 24th to
stoilivanov 1:f7206e74c970 5 28th of October 2017 with instructors Dr. Masahiko Yamazaki, Mr. Takafumi
stoilivanov 1:f7206e74c970 6 Umezawa and Mr. Riku Sato.
stoilivanov 1:f7206e74c970 7
stoilivanov 1:f7206e74c970 8 For contacting the developers, please use e-mails:
stoilivanov 1:f7206e74c970 9 ipmihov@gmail.com - Ivan Mihov
stoilivanov 1:f7206e74c970 10 stoil.n.ivanov@gmail.com - Stoil Ivanov
stoilivanov 1:f7206e74c970 11 z.dimitrov91@gmail.com - Zdravko Dimitrov
stoilivanov 1:f7206e74c970 12 We will be glad to help!*/
stoilivanov 1:f7206e74c970 13
stoilivanov 0:95bf84c286f5 14 #include "mbed.h"
stoilivanov 0:95bf84c286f5 15 #include "SDFileSystem.h"
stoilivanov 0:95bf84c286f5 16 #include "HeptaXbee.h"
stoilivanov 0:95bf84c286f5 17 #include "HeptaCamera_GPS.h"
stoilivanov 0:95bf84c286f5 18 #include "Hepta9axis.h"
stoilivanov 0:95bf84c286f5 19 #include "HeptaTemp.h"
stoilivanov 0:95bf84c286f5 20 #include "HeptaBattery.h"
stoilivanov 0:95bf84c286f5 21 #include <stdio.h>
stoilivanov 0:95bf84c286f5 22 #include <string.h>
stoilivanov 0:95bf84c286f5 23 #include <stdlib.h>
stoilivanov 0:95bf84c286f5 24
stoilivanov 0:95bf84c286f5 25
stoilivanov 0:95bf84c286f5 26 Serial pc(USBTX,USBRX);
stoilivanov 0:95bf84c286f5 27 SDFileSystem sd(p5, p6, p7, p8, "sd");
stoilivanov 0:95bf84c286f5 28 HeptaXbee xbee(p9,p10);
stoilivanov 0:95bf84c286f5 29 HeptaCamera_GPS cam_gps(p13, p14,p25,p24);
stoilivanov 0:95bf84c286f5 30 Hepta9axis n_axis(p28,p27,0xD0,0x18);
stoilivanov 0:95bf84c286f5 31 HeptaTemp temp(p17);
stoilivanov 0:95bf84c286f5 32 AnalogIn light(p18);
stoilivanov 0:95bf84c286f5 33 PwmOut led(p21);
stoilivanov 0:95bf84c286f5 34 HeptaBattery battery(p16,p26);
stoilivanov 0:95bf84c286f5 35 DigitalOut myled(LED1);
stoilivanov 0:95bf84c286f5 36
stoilivanov 1:f7206e74c970 37
stoilivanov 1:f7206e74c970 38 //Definition of MORSE and ASCII structure variables
stoilivanov 0:95bf84c286f5 39 typedef struct {
stoilivanov 1:f7206e74c970 40 char* morse;
stoilivanov 1:f7206e74c970 41 char* ascii;
stoilivanov 0:95bf84c286f5 42 } morse_table_t;
stoilivanov 0:95bf84c286f5 43
stoilivanov 0:95bf84c286f5 44 int main()
stoilivanov 0:95bf84c286f5 45 {
stoilivanov 0:95bf84c286f5 46
stoilivanov 1:f7206e74c970 47 //Morse code dictionary
stoilivanov 1:f7206e74c970 48 morse_table_t table[] = { {".-", "A"},
stoilivanov 1:f7206e74c970 49 {"-...", "B"},
stoilivanov 1:f7206e74c970 50 {"-.-.", "C"},
stoilivanov 1:f7206e74c970 51 {"-.." , "D"},
stoilivanov 1:f7206e74c970 52 {"." , "E"},
stoilivanov 1:f7206e74c970 53 {"..-." , "F"},
stoilivanov 1:f7206e74c970 54 {"--." , "G"},
stoilivanov 1:f7206e74c970 55 {"...." , "H"},
stoilivanov 1:f7206e74c970 56 {".." , "I"},
stoilivanov 1:f7206e74c970 57 {".---" , "J"},
stoilivanov 1:f7206e74c970 58 {"-.-" , "K"},
stoilivanov 1:f7206e74c970 59 {".-.." , "L"},
stoilivanov 1:f7206e74c970 60 {"--" , "M"},
stoilivanov 1:f7206e74c970 61 {"-." , "N"},
stoilivanov 1:f7206e74c970 62 {"---" , "O"},
stoilivanov 1:f7206e74c970 63 {".--." , "P"},
stoilivanov 1:f7206e74c970 64 {"--.-" , "Q"},
stoilivanov 1:f7206e74c970 65 {".-." , "R"},
stoilivanov 1:f7206e74c970 66 {"..." , "S"},
stoilivanov 1:f7206e74c970 67 {"-" , "T"},
stoilivanov 1:f7206e74c970 68 {"..-" , "U"},
stoilivanov 1:f7206e74c970 69 {"...-" , "V"},
stoilivanov 1:f7206e74c970 70 {".--" , "W"},
stoilivanov 1:f7206e74c970 71 {"-..-" , "X"},
stoilivanov 1:f7206e74c970 72 {"-.--" , "Y"},
stoilivanov 1:f7206e74c970 73 {"--.." "Z"},
stoilivanov 1:f7206e74c970 74 {"-----" ,"0"},
stoilivanov 1:f7206e74c970 75 {".----" ,"1"},
stoilivanov 1:f7206e74c970 76 {"..---" , "2"},
stoilivanov 1:f7206e74c970 77 {"...--" , "3"},
stoilivanov 1:f7206e74c970 78 {"....-" , "4"},
stoilivanov 1:f7206e74c970 79 {"....." , "5"},
stoilivanov 1:f7206e74c970 80 {"-...." ,"6"},
stoilivanov 1:f7206e74c970 81 {"--..." , "7"},
stoilivanov 1:f7206e74c970 82 {"---.." , "8"},
stoilivanov 1:f7206e74c970 83 {"----." , "9"},
stoilivanov 1:f7206e74c970 84 {"/" , " "}
stoilivanov 1:f7206e74c970 85 };
stoilivanov 1:f7206e74c970 86 pc.baud(9600);
stoilivanov 0:95bf84c286f5 87
stoilivanov 1:f7206e74c970 88 char symbol,space;
stoilivanov 1:f7206e74c970 89 char mes[100];
stoilivanov 1:f7206e74c970 90 float count=0.0,count_on=0.0,count_off=0.0 ;
stoilivanov 1:f7206e74c970 91 float current,vol,sig,lux;
stoilivanov 1:f7206e74c970 92
stoilivanov 1:f7206e74c970 93 led = 1;
stoilivanov 0:95bf84c286f5 94
stoilivanov 1:f7206e74c970 95 //Creating directory for storing the laser message on the SD card
stoilivanov 1:f7206e74c970 96 mkdir("/sd/LaserComms", 0777);
stoilivanov 1:f7206e74c970 97
stoilivanov 1:f7206e74c970 98 //Creating and opening a file 'for writing' the morse message
stoilivanov 1:f7206e74c970 99 FILE *fp = fopen("/sd/LaserComms/message.txt", "w");
stoilivanov 1:f7206e74c970 100 if(fp == NULL) {
stoilivanov 1:f7206e74c970 101 error("Could not open file for writing\r\n");
stoilivanov 1:f7206e74c970 102 }
stoilivanov 0:95bf84c286f5 103
stoilivanov 1:f7206e74c970 104 //Sequence for 'start bit'
stoilivanov 1:f7206e74c970 105 while (1) {
stoilivanov 1:f7206e74c970 106 do {
stoilivanov 1:f7206e74c970 107 vol = light.read();
stoilivanov 1:f7206e74c970 108 sig = 3.3*1.947*vol;
stoilivanov 1:f7206e74c970 109 current = sig * 100;
stoilivanov 1:f7206e74c970 110 lux = (current)*2;
stoilivanov 1:f7206e74c970 111
stoilivanov 1:f7206e74c970 112 if (lux > 300) {
stoilivanov 1:f7206e74c970 113 count = count + 0.1;
stoilivanov 1:f7206e74c970 114 } else {
stoilivanov 1:f7206e74c970 115 count = 0.0;
stoilivanov 1:f7206e74c970 116 }
stoilivanov 0:95bf84c286f5 117
stoilivanov 1:f7206e74c970 118 xbee.printf("lux= %f , current= %f ,vol= %f , count= %f \r\n",lux,current,vol,count);
stoilivanov 1:f7206e74c970 119 wait (0.1);
stoilivanov 1:f7206e74c970 120 } while (count <= 3.0); //Condition for 'start bit'
stoilivanov 0:95bf84c286f5 121
stoilivanov 1:f7206e74c970 122 //'Start bit' received
stoilivanov 0:95bf84c286f5 123 xbee.printf("LASER COMMUNICATION ESTABLISHED! RECEIVING MODE ON!\r\n");
stoilivanov 0:95bf84c286f5 124
stoilivanov 1:f7206e74c970 125 //Laser signal reading starts
stoilivanov 1:f7206e74c970 126 lux=0;
stoilivanov 1:f7206e74c970 127 while(1) {
stoilivanov 1:f7206e74c970 128 count_on = 0.0;
stoilivanov 1:f7206e74c970 129 count_off = 0.0;
stoilivanov 0:95bf84c286f5 130
stoilivanov 1:f7206e74c970 131 //----------- While loop for 'spaces' in the message
stoilivanov 1:f7206e74c970 132 while(lux < 300) {
stoilivanov 1:f7206e74c970 133 xbee.printf("lux= %f, count_off= %f \r\n",lux,count_off);
stoilivanov 1:f7206e74c970 134 count_off = count_off + 0.05;
stoilivanov 1:f7206e74c970 135 wait(0.05);
stoilivanov 1:f7206e74c970 136 vol = light.read();
stoilivanov 1:f7206e74c970 137 sig = 3.3*1.947*vol;
stoilivanov 1:f7206e74c970 138 current = sig * 100;
stoilivanov 1:f7206e74c970 139 lux = (current)*2;
stoilivanov 1:f7206e74c970 140 }
stoilivanov 1:f7206e74c970 141
stoilivanov 1:f7206e74c970 142 //Condition for defining the type of the 'space signal'
stoilivanov 1:f7206e74c970 143 //Currently developed for single words only
stoilivanov 1:f7206e74c970 144 if (count_off >= 0.5) {
stoilivanov 1:f7206e74c970 145 space = 'x';
stoilivanov 1:f7206e74c970 146 fprintf(fp,"%c",space);
stoilivanov 1:f7206e74c970 147 }
stoilivanov 0:95bf84c286f5 148
stoilivanov 1:f7206e74c970 149 //Check for 'stop bit'
stoilivanov 1:f7206e74c970 150 if (count_off > 3.0) {
stoilivanov 1:f7206e74c970 151 break;
stoilivanov 1:f7206e74c970 152 }
stoilivanov 0:95bf84c286f5 153
stoilivanov 1:f7206e74c970 154 //----------- While loop for 'symbols' in the message
stoilivanov 1:f7206e74c970 155 while(lux >= 300) {
stoilivanov 1:f7206e74c970 156 xbee.printf("lux= %f, count_on= %f \r\n",lux,count_on);
stoilivanov 1:f7206e74c970 157 count_on = count_on + 0.05;
stoilivanov 1:f7206e74c970 158 wait(0.05);
stoilivanov 1:f7206e74c970 159 vol = light.read();
stoilivanov 1:f7206e74c970 160 sig = 3.3*1.947*vol;
stoilivanov 1:f7206e74c970 161 current = sig * 100;
stoilivanov 1:f7206e74c970 162 lux = (current)*2;
stoilivanov 1:f7206e74c970 163 }
stoilivanov 1:f7206e74c970 164
stoilivanov 1:f7206e74c970 165 //Condition for defining the type of the 'symbol signal'
stoilivanov 1:f7206e74c970 166 if (count_on >= 0.5) {
stoilivanov 1:f7206e74c970 167 symbol = '-';
stoilivanov 1:f7206e74c970 168 fprintf(fp,"%c",symbol);
stoilivanov 1:f7206e74c970 169 } else {
stoilivanov 1:f7206e74c970 170 symbol = '.';
stoilivanov 1:f7206e74c970 171 fprintf(fp,"%c",symbol);
stoilivanov 1:f7206e74c970 172 }
stoilivanov 0:95bf84c286f5 173
stoilivanov 1:f7206e74c970 174 //Check for 'stop bit'
stoilivanov 1:f7206e74c970 175 if (count_off > 3.0) {
stoilivanov 1:f7206e74c970 176 break;
stoilivanov 1:f7206e74c970 177 }
stoilivanov 1:f7206e74c970 178 }
stoilivanov 0:95bf84c286f5 179
stoilivanov 1:f7206e74c970 180 //At this point the 'stop bit' has been received
stoilivanov 1:f7206e74c970 181 fclose(fp);
stoilivanov 0:95bf84c286f5 182
stoilivanov 1:f7206e74c970 183 //The message was written in a file on the SD card
stoilivanov 0:95bf84c286f5 184
stoilivanov 1:f7206e74c970 185 //Now we open the same file to read the message and store it in a string
stoilivanov 1:f7206e74c970 186 fp = fopen("/sd/LaserComms/message.txt","r");
stoilivanov 1:f7206e74c970 187 fgets(mes,100,fp);
stoilivanov 1:f7206e74c970 188 fclose(fp);
stoilivanov 0:95bf84c286f5 189
stoilivanov 1:f7206e74c970 190 //Check if the message is not empty
stoilivanov 1:f7206e74c970 191 if (mes != "\0") {
stoilivanov 1:f7206e74c970 192 xbee.printf("Message accepted successfully! \r\n");
stoilivanov 1:f7206e74c970 193 xbee.printf("Morse: %s\r\n Translating... \r\n",mes);
stoilivanov 1:f7206e74c970 194 }
stoilivanov 0:95bf84c286f5 195
stoilivanov 1:f7206e74c970 196 //Definitiom of characters and strings for the Morse Code Translator
stoilivanov 1:f7206e74c970 197 char* segment;
stoilivanov 1:f7206e74c970 198 char final_mes[100];
stoilivanov 1:f7206e74c970 199 int i;
stoilivanov 0:95bf84c286f5 200
stoilivanov 1:f7206e74c970 201 //Here we divide the message in 'segments' using the symbol for space 'x'
stoilivanov 1:f7206e74c970 202 segment = strtok(mes, "x");
stoilivanov 1:f7206e74c970 203
stoilivanov 1:f7206e74c970 204 xbee.printf("Translated: ");
stoilivanov 1:f7206e74c970 205
stoilivanov 1:f7206e74c970 206 //We create a file to store the final translated message
stoilivanov 1:f7206e74c970 207 FILE *fh = fopen("/sd/LaserComms/final_message.txt", "w");
stoilivanov 1:f7206e74c970 208 if(fh == NULL) {
stoilivanov 1:f7206e74c970 209 error("Could not open file for writing\r\n");
stoilivanov 1:f7206e74c970 210 }
stoilivanov 0:95bf84c286f5 211
stoilivanov 1:f7206e74c970 212 //The Morse-to- text translation sequence starts
stoilivanov 1:f7206e74c970 213 while(segment) {
stoilivanov 1:f7206e74c970 214 for(i=0; i<37; ++i) {
stoilivanov 1:f7206e74c970 215 //Here we compare the message segment with the defined Morse code dictionary
stoilivanov 1:f7206e74c970 216 if (!strcmp(segment, table[i].morse)) {
stoilivanov 1:f7206e74c970 217 //The translated message is sent to the Ground Station
stoilivanov 1:f7206e74c970 218 xbee.printf("%s",(table[i].ascii));
stoilivanov 1:f7206e74c970 219 //The translated message is stored in a file on the SD card
stoilivanov 1:f7206e74c970 220 fprintf(fh,"%s",(table[i].ascii));
stoilivanov 1:f7206e74c970 221 break;
stoilivanov 1:f7206e74c970 222 }
stoilivanov 1:f7206e74c970 223 }
stoilivanov 1:f7206e74c970 224 segment = strtok(NULL, "x");
stoilivanov 1:f7206e74c970 225 }
stoilivanov 1:f7206e74c970 226 fclose(fh);
stoilivanov 0:95bf84c286f5 227
stoilivanov 1:f7206e74c970 228 //We open the file, which contains the translated message
stoilivanov 1:f7206e74c970 229 fh = fopen("/sd/LaserComms/final_message.txt","r");
stoilivanov 1:f7206e74c970 230 //The file is read and the translated message is stored in a string
stoilivanov 1:f7206e74c970 231 fgets(final_mes,100,fh);
stoilivanov 1:f7206e74c970 232 fclose(fh);
stoilivanov 0:95bf84c286f5 233
stoilivanov 1:f7206e74c970 234 //From here on we define few commands, depending on the message content
stoilivanov 0:95bf84c286f5 235
stoilivanov 1:f7206e74c970 236 //------- TELEMETRY COMMAND
stoilivanov 1:f7206e74c970 237 if (!strcmp(final_mes, "TELEMETRY")) {
stoilivanov 1:f7206e74c970 238 xbee.printf("Telemetry requested!");
stoilivanov 1:f7206e74c970 239 cam_gps.gps_setting();
stoilivanov 1:f7206e74c970 240 float gx,gy,gz,ax,ay,az,mx,my,mz,bt,temper;
stoilivanov 1:f7206e74c970 241 char ns='A',ew='B',aunit='m';
stoilivanov 1:f7206e74c970 242 float time=0.0,latitude=0.0,longitude=0.0,hacu=0.0,altitude=0.0;
stoilivanov 1:f7206e74c970 243 int quality=0,stnum=0,gps_check=0;
stoilivanov 1:f7206e74c970 244 for(int i = 0; i < 10; i++) {
stoilivanov 1:f7206e74c970 245 n_axis.sen_gyro(&gx,&gy,&gz);
stoilivanov 1:f7206e74c970 246 n_axis.sen_acc(&ax,&ay,&az);
stoilivanov 1:f7206e74c970 247 n_axis.sen_mag(&mx,&my,&mz);
stoilivanov 1:f7206e74c970 248 battery.vol(&bt);
stoilivanov 1:f7206e74c970 249 temp.temp_sense(&temper);
stoilivanov 1:f7206e74c970 250 cam_gps.gga_sensing(&time, &latitude, &ns, &longitude, &ew, &quality, &stnum, &hacu, &altitude, &aunit, &gps_check);
stoilivanov 1:f7206e74c970 251 xbee.printf("gx = %f gy = %f gz = %f\r\n",gx,gy,gz);
stoilivanov 1:f7206e74c970 252 xbee.printf("ax = %f ay = %f az = %f\r\n",ax,ay,az);
stoilivanov 1:f7206e74c970 253 xbee.printf("mx = %f my = %f mz = %f\r\n",mx,my,mz);
stoilivanov 1:f7206e74c970 254 xbee.printf("Temperature = %f\r\n",temper);
stoilivanov 1:f7206e74c970 255 xbee.printf("Battery voltage: = %f[V]\r\n",bt);
stoilivanov 1:f7206e74c970 256 xbee.printf("%f,%f,%c,%f,%c,%d,%d,%f,%f,%c\r\n\n",time,latitude,ns,longitude,ew,quality,stnum,hacu,altitude,aunit);
stoilivanov 1:f7206e74c970 257 led = (i%2);
stoilivanov 1:f7206e74c970 258 wait(1.0);
stoilivanov 1:f7206e74c970 259 }
stoilivanov 1:f7206e74c970 260 xbee.initialize();
stoilivanov 1:f7206e74c970 261 }
stoilivanov 0:95bf84c286f5 262
stoilivanov 1:f7206e74c970 263 //------- PHOTO COMMAND
stoilivanov 1:f7206e74c970 264 if (!strcmp(final_mes, "PHOTO")) {
stoilivanov 1:f7206e74c970 265 //---------LED blinks several times
stoilivanov 1:f7206e74c970 266 for(int i = 0; i < 7; i++) {
stoilivanov 1:f7206e74c970 267 led = (i%2);
stoilivanov 1:f7206e74c970 268 wait(0.2);
stoilivanov 1:f7206e74c970 269 }
stoilivanov 0:95bf84c286f5 270
stoilivanov 1:f7206e74c970 271 xbee.printf("Photo requested! \r\n Camera Snapshot Mode\r\n\n Please, smile! :) \r\n");
stoilivanov 1:f7206e74c970 272 cam_gps.Sync();
stoilivanov 1:f7206e74c970 273 cam_gps.initialize(HeptaCamera_GPS::Baud115200, HeptaCamera_GPS::JpegResolution640x480);
stoilivanov 1:f7206e74c970 274 cam_gps.test_jpeg_snapshot_picture(1);
stoilivanov 1:f7206e74c970 275 led = 1;
stoilivanov 1:f7206e74c970 276 }
stoilivanov 0:95bf84c286f5 277
stoilivanov 1:f7206e74c970 278 //------- SOS COMMAND
stoilivanov 1:f7206e74c970 279 if (!strcmp(final_mes, "SOS")) {
stoilivanov 0:95bf84c286f5 280
stoilivanov 0:95bf84c286f5 281 // LED blinks SOS message
stoilivanov 1:f7206e74c970 282 xbee.printf("LEDs blinks SOS message! \r\n");
stoilivanov 0:95bf84c286f5 283
stoilivanov 1:f7206e74c970 284 led=0;
stoilivanov 1:f7206e74c970 285 wait(0.2);
stoilivanov 0:95bf84c286f5 286
stoilivanov 1:f7206e74c970 287 // 'S' letter: . . .
stoilivanov 1:f7206e74c970 288 led = 1;
stoilivanov 1:f7206e74c970 289 wait(0.2);
stoilivanov 1:f7206e74c970 290
stoilivanov 1:f7206e74c970 291 led = 0;
stoilivanov 1:f7206e74c970 292 wait(0.2);
stoilivanov 1:f7206e74c970 293
stoilivanov 1:f7206e74c970 294 led = 1;
stoilivanov 1:f7206e74c970 295 wait(0.2);
stoilivanov 1:f7206e74c970 296
stoilivanov 1:f7206e74c970 297 led = 0;
stoilivanov 1:f7206e74c970 298 wait(0.2);
stoilivanov 1:f7206e74c970 299
stoilivanov 1:f7206e74c970 300 led = 1;
stoilivanov 1:f7206e74c970 301 wait(0.2);
stoilivanov 1:f7206e74c970 302
stoilivanov 1:f7206e74c970 303 //Space between letters
stoilivanov 1:f7206e74c970 304 led = 0;
stoilivanov 1:f7206e74c970 305 wait(0.7);
stoilivanov 0:95bf84c286f5 306
stoilivanov 1:f7206e74c970 307 // 'O' letter: - - -
stoilivanov 1:f7206e74c970 308 led = 1;
stoilivanov 1:f7206e74c970 309 wait(0.7);
stoilivanov 1:f7206e74c970 310
stoilivanov 1:f7206e74c970 311 led = 0;
stoilivanov 1:f7206e74c970 312 wait(0.2);
stoilivanov 1:f7206e74c970 313
stoilivanov 1:f7206e74c970 314 led = 1;
stoilivanov 1:f7206e74c970 315 wait(0.7);
stoilivanov 1:f7206e74c970 316
stoilivanov 1:f7206e74c970 317 led = 0;
stoilivanov 1:f7206e74c970 318 wait(0.2);
stoilivanov 0:95bf84c286f5 319
stoilivanov 1:f7206e74c970 320 led = 1;
stoilivanov 1:f7206e74c970 321 wait(0.7);
stoilivanov 1:f7206e74c970 322
stoilivanov 1:f7206e74c970 323 //Space between letters
stoilivanov 1:f7206e74c970 324 led = 0;
stoilivanov 1:f7206e74c970 325 wait(0.7);
stoilivanov 1:f7206e74c970 326
stoilivanov 1:f7206e74c970 327 // 'S' letter: . . .
stoilivanov 1:f7206e74c970 328 led = 1;
stoilivanov 1:f7206e74c970 329 wait(0.2);
stoilivanov 1:f7206e74c970 330
stoilivanov 1:f7206e74c970 331 led = 0;
stoilivanov 1:f7206e74c970 332 wait(0.2);
stoilivanov 1:f7206e74c970 333
stoilivanov 1:f7206e74c970 334 led = 1;
stoilivanov 1:f7206e74c970 335 wait(0.2);
stoilivanov 1:f7206e74c970 336
stoilivanov 1:f7206e74c970 337 led = 0;
stoilivanov 1:f7206e74c970 338 wait(0.2);
stoilivanov 1:f7206e74c970 339
stoilivanov 1:f7206e74c970 340 led = 1;
stoilivanov 1:f7206e74c970 341 wait(0.2);
stoilivanov 1:f7206e74c970 342
stoilivanov 1:f7206e74c970 343 led = 0;
stoilivanov 1:f7206e74c970 344 xbee.printf("SOS message sent back the Earth with the LED! \r\n");
stoilivanov 1:f7206e74c970 345 }
stoilivanov 1:f7206e74c970 346 }
stoilivanov 0:95bf84c286f5 347 }