main.cpp

00001 /**
00002  * XBee Example Test
00003  * A test application that demonstrates the ability
00004  * of transmitting serial data via an XBee module with
00005  * an mbed microprocesor.
00006  * By: Vlad Cazan
00007  * Date: Tuesday, September 29th 2009
00008  */
00009 
00010 #include "mbed.h"
00011 #include "rtos.h"
00012 #include <string>
00013 #include <vector>
00014 
00015 Serial xbee1(p9, p10); //Creates a variable for serial comunication through pin 9 and 10
00016 DigitalOut rst1(p11); //Digital reset for the XBee, 200ns for reset
00017 DigitalOut myled(LED3);//Create variable for Led 3 on the mbed
00018 DigitalOut myled2(LED4);//Create variable for Led 4 on the mbed
00019 vector<string> studentNames;
00020 vector<string> serialNumbers;
00021 vector<string> studentIds;
00022 Serial pc(USBTX, USBRX);//Opens up serial communication through the USB port via the computer
00023 char c;
00024 PinName _tx = p9;
00025 PinName _rx = p10;
00026 
00027 int ConfigMode()
00028 {
00029     int a;
00030     Serial DATA(_tx,_rx);
00031     wait(2);
00032     DATA.printf("+++");
00033     while (a != 75) {
00034         if (DATA.readable()) {
00035             a = DATA.getc();
00036         }
00037     }
00038     wait(1);
00039     printf("Configuration Complete!\n\n");
00040     return 1;
00041 }
00042 
00043 int GetSerial(int *serial_no)
00044 {
00045     //pc.printf("Start - GetSerial");
00046     int sh1,sh2,sh3,sl1,sl2,sl3,sl4;
00047     Serial DATA(_tx,_rx);
00048     wait_ms(50);
00049     DATA.printf("ATSL \r");
00050     DATA.scanf ("%2x%2x%2x%2x",&sl1,&sl2,&sl3,&sl4);
00051     wait_ms(500);
00052     DATA.printf("ATSH \r");
00053     DATA.scanf ("%2x%2x%2x",&sh1,&sh2,&sh3);
00054  
00055     serial_no[0] = sh1;
00056     serial_no[1] = sh2;
00057     serial_no[2] = sh3;
00058     serial_no[3] = sl1;
00059     serial_no[4] = sl2;
00060     serial_no[5] = sl3;
00061     serial_no[6] = sl4;
00062     //pc.printf("End - GetSerial");
00063     return 1;
00064 }
00065 
00066 int SetKey(char* key)
00067 {
00068     //pc.printf("Start - SetKey");
00069     Serial DATA(_tx,_rx);
00070     DATA.printf("ATEE 0 \r");
00071     char sec_key[8] = {'h','e','l','l','o','m','o','b'};
00072     DATA.scanf ("%*s");
00073     wait_ms(1);
00074     DATA.printf("ATKY %s \r",sec_key);
00075     DATA.scanf ("%*s");
00076     //pc.printf("End - SetKey");
00077     return 1;
00078 }
00079 
00080 int SetPanId(int pan_id)
00081 {
00082     //pc.printf("Start - PanId");
00083     Serial DATA(_tx,_rx);
00084     wait_ms(5);
00085     DATA.printf("ATID %i\r",pan_id);
00086     DATA.scanf ("%*s");
00087     //pc.printf("End - PanID");
00088     return 1;
00089 }
00090 
00091 int WriteSettings()
00092 {
00093     //pc.printf("Start - WriteSettings");
00094     Serial DATA(_tx,_rx);
00095     wait_ms(5);
00096     DATA.printf("ATWR \r");
00097     DATA.scanf ("%*s");
00098     //pc.printf("End - WriteSettings");
00099     return 1;
00100 }
00101 
00102 int ExitConfigMode()
00103 {
00104     //pc.printf("Start - ExitConfig");
00105     Serial DATA(_tx,_rx);
00106     wait_ms(5);
00107     DATA.printf("ATCN \r");
00108     DATA.scanf ("%*s");
00109     //pc.printf("End - ExitConfig");
00110     return 1;
00111 }
00112 
00113 void Reset()
00114 {
00115     //pc.printf("Start - Reset");
00116     rst1 = 0;
00117     wait_ms(10);
00118     rst1 = 1;
00119     wait_ms(1);
00120     //pc.printf("End - Reset");
00121 }
00122 
00123 int read_sentence(char* input){
00124 
00125     char tmp;
00126     while(!pc.readable());
00127     tmp = pc.getc();
00128     pc.putc(tmp);
00129     int counter = 0;
00130     while(tmp != '\n'){
00131         input[counter] = tmp;
00132         if(pc.readable()){
00133             tmp = pc.getc();
00134             pc.putc(tmp);
00135             counter++;
00136         } 
00137     }
00138     
00139     pc.printf("\n");
00140     return counter-1;
00141 }
00142 
00143 int read_xbee_sentence(char* input){
00144     char tmp;
00145     while(!xbee1.readable());
00146     tmp = xbee1.getc();
00147     int counter = 0;
00148     while(tmp != '\n'){
00149         input[counter] = tmp;
00150         if(xbee1.readable()){
00151             tmp = xbee1.getc();
00152             counter++;
00153         } 
00154     }
00155     return counter;
00156 }
00157 
00158 void print_assessment_available(void const *args){
00159   pc.printf("Broadcasting assessment available message to all the clickers in the room!\n");
00160   while(1){
00161    xbee1.printf("Available\n");
00162    Thread::wait(100);
00163   }
00164 }
00165 
00166 int main() {
00167     rst1 = 0; //Set reset pin to 0
00168     myled = 0;//Set LED3 to 0
00169     myled2= 0;//Set LED4 to 0
00170     wait_ms(1);//Wait at least one millisecond
00171     rst1 = 1;//Set reset pin to 1
00172     wait_ms(1);//Wait another millisecond
00173     pc.printf("Teacher Machine\n");
00174     pc.printf("Start a new assessment? (y/n)\n");
00175     char sentence_store[255];
00176     char begin_assessment = 'o';
00177     char temp;
00178     int char_count;
00179     while(begin_assessment == 'o'){
00180       if(pc.readable()){
00181          temp = pc.getc();   
00182       }
00183       if(temp == 'y' || temp == 'n' || temp == 'Y' || temp == 'N'){
00184          begin_assessment = temp;   
00185       }
00186     }
00187     pc.putc(begin_assessment);
00188     pc.printf("\n");
00189     if(begin_assessment == 'n' || begin_assessment == 'N'){
00190       pc.printf("Ok. This program will exit momentarily");   
00191     }else{
00192         pc.printf("Great! The assessment process begins!\n");
00193         pc.printf("We are configuring a few things. Wait for a few seconds!\n");
00194         int device_serial[8];
00195         char sec_key[8] = {'h','e','l','l','o','m','o','b'};
00196         int pan_id = 5;
00197         int assessment_id = rand() % 100 + 1;
00198         ConfigMode();
00199         GetSerial(device_serial);
00200         SetKey(sec_key);
00201         SetPanId(pan_id);
00202         WriteSettings();
00203         //ExitConfigMode();
00204         Reset();
00205         pc.printf("Your students will need these parameters to configure their clickers!\n");
00206         pc.printf("Channel Number: %d\n", pan_id);
00207         pc.printf("How many questions are going to be in the assessment?\n");
00208         char_count = read_sentence(sentence_store);
00209         int number_of_questions;
00210         number_of_questions = atoi (sentence_store);
00211         char answer_store[number_of_questions];
00212         pc.printf("Please enter the correct answer for each of the questions\n");
00213         for(int j = 0;j < number_of_questions; j++){
00214             pc.printf("Question %d - Correct Answer: ",j+1);
00215             read_sentence(sentence_store);
00216             answer_store[j] = sentence_store[0];
00217             pc.printf("\n");   
00218         }
00219         pc.printf("Great! The answer key is now set!\n");
00220         pc.printf("The system will start accepting connections\n");
00221         pc.printf("Waiting for student clickers to connect!\n");
00222         //Thread t(&print_assessment_available);
00223         int attack_detector = 0;
00224         while (1) {//Neverending Loop
00225              // if(pc.readable()){
00226             if (xbee1.readable()){
00227                string input;
00228                char poll_id[255];
00229                char_count = read_xbee_sentence(poll_id);
00230                char set_poll_id[char_count];
00231                for(int i = 0;i < char_count; i++){
00232                     set_poll_id[i] = poll_id[i];    
00233                }
00234                input = string(set_poll_id);
00235                pc.printf(input.c_str());
00236                pc.printf("\n");
00237                if(input.find("C-") != -1 && attack_detector == 0){
00238                  int cdash = input.find_last_of("-");
00239                  pc.printf("A clicker with #%s is trying to connect\n",input.substr(cdash+1,input.length()-1).c_str());
00240                  pc.printf("NReq-%s\n",input.substr(cdash+1,input.length()-1).c_str());
00241                  xbee1.printf("NReq-%s\n",input.substr(cdash+1,input.length()-1).c_str());
00242                  attack_detector++;
00243                  pc.printf("%d",attack_detector);   
00244                }else if(input.find("NRes-") != -1 && attack_detector == 1){
00245                  pc.printf("The student %s has begun his/her assessment\n",input.substr(15,input.length()-1).c_str());
00246                  pc.printf("Requesting his/her ID number\n");
00247                  int length = input.length();
00248                  int ndash = input.find_last_of("-");
00249                  pc.printf("IDReq-%s\n",input.substr(15,length-1).c_str());
00250                  xbee1.printf("IDReq-%s\n",input.substr(15,length-1).c_str());
00251                  attack_detector++; 
00252                }else if(input.find("IDRes-") != -1 && attack_detector == 2){
00253                  pc.printf(input.c_str());
00254                  pc.printf("The student's ID number is %s\n",input.substr(6,input.length()-1).c_str());
00255                  pc.printf("Sending the clicker the question number count\n");
00256                  pc.printf("QC-%d-%d\n",assessment_id,number_of_questions);
00257                  xbee1.printf("QC-%d-%d\n",assessment_id,number_of_questions);
00258                  attack_detector++;   
00259                }else if(input.find("QA-") != -1 && attack_detector == 3){
00260                  pc.printf("Question count has been acknowledged!\n");
00261                  pc.printf("Now waiting for answers to be sent!\n");
00262                  attack_detector++;    
00263                } else if(input.find("ANS-") != -1 && attack_detector == 4){
00264                  pc.printf("Answers from the clicker has been received!\n");
00265                  int dash = input.find_last_of("-");
00266                  string k = input.substr(dash+1,input.length()-1);
00267                  string answer_key;
00268                  answer_key = string(answer_store);
00269                  int correct = 0;
00270                  for(int i = 0; i < answer_key.length(); i++){
00271                     if(answer_key[i] == k[i]){
00272                       correct++;   
00273                     }
00274                  }
00275                  float grade = (float) (correct/number_of_questions)*100.0;
00276                  pc.printf("Output grade - %f\n", grade);
00277                  xbee1.printf("GRADE-%f",grade);
00278                  attack_detector++;
00279                 } else if(input.find("AA") != -1){
00280                   xbee1.printf("Available\n");   
00281                 }
00282             }
00283         }
00284      }
00285 }