File content as of revision 0:6cba4a800507:

/************************************************************
*                   University of Dundee                    *
*   ME21001 - Software Applications for Engineering Design  *
*               Traffic Intersection Project                *
*                       Group 3                             *
*                Alvaro Almeida Arencibia                   *
*                     Adams Boyd                            *
*                      Qiushuhao                            *
*                                                           *
*   This progam will control 4 traffic lights               *
*   with the intervention of a train                        *
*                                                           *
*   For this program we will have 7 leds as outputs and 3   *
*   inputs; 2 Ldrs and 1 switch                             *
************************************************************/ 



#include "mbed.h"                   // We include the library called "mbed.h"

DigitalOut redled1 (p23);           // pin 23 is declared as an output with the name of redled1 (this led wiill be for the cars)
DigitalOut redledp (p21);           // pin 21 is declared as an output with the name of redledp (this led will be for the pedestrians)
DigitalOut greenled1 (p24);         // pin 24 is declared as an output with the name of greenled1 (this led will be for the cars)
DigitalOut greenledp (p27);         // pin 27 is declared as an output with the name of greenledp (this led will be for the pedestrians)
DigitalOut yellowled1 (p22);        // pin 22 is declared as an output with the name of yellowled1 (this led will be for the cars)
DigitalIn switchstate (p10);        // pin 10 is declared as an input with the name of switchstate (this switch will be used by the pedestrians)
DigitalIn LDR1 (p17);               // pin 17 is declared as an input with the name of  LDR1 (this LDR will be in charge to see if there are cars in the middle of the junctions)
DigitalIn LDR2 (p18);               // pin 18 is declared as an input with the name of LDR2 (this LDR will observe if there are is any train coming)
DigitalOut myspeaker (LED1);        // LED1 is declared as an output with the name of myspeaker as this led will simulate an alarm
DigitalOut LED(LED2);               // LED2 is declared as an output with the name of LED2

int alarm=0;                        // A variable named as "alarm", with an initial value of 0, is defined
int state=1;                        // A variable named as "state", with an initial value of 1, is defined

void train () {                     // A new function named as "train" is declared
 greenled1=0;                       // greenled1 is turned off
 yellowled1=1;                      // yellowled1 is turned on
 wait(5);                           // wait for 5 seconds 
 redled1=1;                         // redled1 is turned on
 yellowled1=0;                      // yellowled1 is turned off
 wait(1);                           // wait for 1 second
 redledp=0;                         // redledp is turned off
 greenledp=1;                       // greenledp is turned on 
 wait(3);                           // wait for 3 seconds
 if(LDR1.read()) {                  // An "if" function is defined, this will make an action if LDR1 detects a lack of light 
     if(LDR1.read()) {              // An "if" function is defined, this will make an action if LDR1 detects a lack of light 
         alarm= alarm+1;            // This comand will increase the value of the variable "alarm" by 1
         wait(2);                   // wait for 2 seconds
     }
     if(LDR1.read()) {              // An "if" function is defined, this will make an action if LDR1 detects a lack of light 
         alarm= alarm+1;            // This comand will increase the value of the variable "alarm" by 1
         wait(2);                   // wait for 2 seconds
     }
     if(LDR1.read()) {              // An "if" function is defined, this will make an action if LDR1 detects a lack of light 
         alarm= alarm+1;            // This comand will increase the value of the variable "alarm" by 1
         wait(2);                   // wait for 2 seconds
     }
     if(alarm==3) {                 // An "if" function is defined, this will make an action if the value of the variable "alarm" is equal to 3
         myspeaker= 1;              // myspeaker1 is turned on
         greenled1=0;               // greenled1 is turned off
         redled1=1;                 // redled1 is turned on
         redledp=1;                 // redledp is turned on
         greenledp=0;               // greenledp is turned off
         wait(50);                  // wait for 50 seconds 
     }
     }
}


void pedestrian() {                 // A new funtion named as "pedestrian" is declared
 if (LDR2.read()) {                 // An "if" function is defined, this will make an action if LDR2 detects a lack of light 
     train();                       // This will do the function "train"
 }
 greenled1=0;                       // greenled1 is turned off
 LED=0;                             // LED is turned off
 yellowled1=1;                      // yellowled1 is turned on
 wait(5);                           // Wait for 5 seconds
 redled1=1;                         // redled1 is turned on
 wait(2);                           // Wait for 2 seconds
 yellowled1=0;                      // yellowled1 is turned off
 wait(1);                           // Wait for 1 second
 redledp=0;                         // redledp is turned off
 greenledp=1;                       // greenledp is turned on
 wait(5);                           // Wait for 5 seconds
 greenledp=0;                       // greenledp is turned off
 redledp=1;                         // redledp is turned on
 wait(1);                           // Wait for 1 second
 yellowled1=1;                      // yellowled1 is turned on
 wait(1);                           // wait for 1 second
 yellowled1=0;                      // yellowled1 is turned off
 redled1=0;                         // redled1 is turned off
 greenled1=1;                       // greenled1 is turned on
 LED=1;                             // LED is turned on
 wait(1);                           // wait for 1 second
 state= state+1;                    // This comand will increase the value of the variable "state" by 1 
}



int main() {
    while(1) {                      // Command that creates an infinite loop
     greenled1=1;                   // greenled1 is turned on
     redledp=1;                     // redledp is turned on
     if(switchstate.read()) {       // An "if" function is defined, this will make an action if switch detects it is being pressed 
        state=state+1;              // This comand will increase the value of the variable "state" by 1 
     }
     if (state>1){                  // An "if" function is defined, this will make an action if the variable "state" is higher than 1
         state=0;                   // This comand will define the value of the variable "state" to 0       
     }
     if(state==0) {                 // An "if" function is defined, this will make an action if the value of the variable "state" is 0
        pedestrian ();              // The function "pedestrian" will be done
     }
     if(LDR2.read()) {              // An "if" function is defined, this will make an action if LDR2 detects a lack of light 
        train();                    // The function "train" will be done
        wait(3);                    // Wait for 3 seconds
        redledp=1;                  // redledp is turned on
        greenledp=0;                // greenledp is turned off
        wait(1);                    // Wait for 1 second
        yellowled1=1;               // yellowled1 is turned on
        wait(1);                    // Wait for 1 second
        redled1=0;                  // redled1 is turned off
        yellowled1=0;               // yellowled1 is turned off
        greenled1=1;                // greenled1 is turned on
        wait(5);                    // Wait for 5 seconds 
     } 
}
}