For this tutorial, you’ll need:
- 2 x Arduino UNO
- 9 x Resistor 330E
- 9 x LED 5MM
- Jumper Wires
- 3x Mini BreadBoard
- 1 x Dip Switch
- 1 x Resistor 10K
Please note that the items needed will be updated with each part!
First Part: Explaining the project & Figure Out How to Know if a Led is Really ON?
Test if a LED is ON:
define led 8
define feedback 7
int i =0;
void setup() {
// put your setup code here, to run once:
Serial.begin(9600);
pinMode(led, OUTPUT);
pinMode(feedback, INPUT);
digitalWrite(led, LOW);
}
void loop() {
// put your main code here, to run repeatedly:
digitalWrite(led, HIGH);
if (digitalRead(feedback) == 1)
{
Serial.println("The led is ON");
}
else
{
Serial.println("The led is damaged");
}
delay(500);
}Second Part: Simple Order Without Sensor Feedback
Simple Order Without Sensor Feedback Code:
define TLAR 3 // RED Traffic Light for Road A
define TLAY 4 // Yellow Traffic Light for Road A
define TLAG 5 // Green Traffic Light for Road A
define TLBCR 6 // RED Traffic Light for Road B & Road C
define TLBCY 7 // Yellow Traffic Light for Road B & Road C
define TLBCG 8 // Green Traffic Light for Road B & Road C
define TLDR 9 // RED Traffic Light for Road D
define TLDY 10 // Yellow Traffic Light for Road D
define TLDG 11 // Green Traffic Light for Road D
define TrafficLedRoadA 1 //This is the reference number for the traffic lights of road A
define TrafficLedRoadBC 2 //This is the reference number for the traffic lights of road B and C
define TrafficLedRoadD 3 //This is the reference number for the traffic lights of road D
define IntinialState 4 //This is the reference number for the initial State of the system
define red 10 //This is the reference number for the red color
define green 20 //This is the reference number for the green color
define yellow 30 //This is the reference number for the yellow color
define IntinialStateColor 50 //This is the reference number of the initiale state color lighted when the system in UP for the first time
define ERRORLIGHTS 404 //This is the reference number for the error State
define ERRORLIGHTSTIMEREPEAT 3 //This is the number of time the yellow lights will blink when there is an error
define ERRORLIGHTSTIME 500 //This is the delay time between each ON & OFF for the error lights
define WaitingTime 9000 //9 Seconds This is the time of the the red light will be ON or the GREEN light will be ON.
define GreenTime 7000 //7 Seconds is the green time (of the 9 total seconds)
define YellowTime 2000 //2 Seconds is the yellow time (of the 9 total seconds)
define SecurityTime 1000 //1 Second is the time to switch the green light to another traffic light. It's when all teh traffic lights are RED ON. For security purposes
int turn=IntinialState; //This variable is used to pass between the turns of the traffic lights
void turnTrafficLedON (int TrafficLedNumber, int colorNumber); // This function will light the specified color based on the traffic light given
/*
Example:
turnTrafficLedON(1, 10);
This will trun RED light ON in TrafficLedRoadA and turn Yellow and Green Lights OFF on the same TrafficLedRoadA
*/
//the turn is ROAD D, ROAD A, ROAD B & C
void setup() {
// put your setup code here, to run once:
//Define all the traffic lights as output - till now we don't have an input in this program
pinMode(TLAR, OUTPUT);
pinMode(TLAY, OUTPUT);
pinMode(TLAG, OUTPUT);
pinMode(TLBCR, OUTPUT);
pinMode(TLBCY, OUTPUT);
pinMode(TLBCG, OUTPUT);
pinMode(TLDR, OUTPUT);
pinMode(TLDY, OUTPUT);
pinMode(TLDG, OUTPUT);
//Turn OFF all the outputs
digitalWrite(TLAG, LOW);
digitalWrite(TLAY, LOW);
digitalWrite(TLAR, LOW);
digitalWrite(TLBCG, LOW);
digitalWrite(TLBCY, LOW);
digitalWrite(TLBCR, LOW);
digitalWrite(TLDG, LOW);
digitalWrite(TLDY, LOW);
digitalWrite(TLDR, LOW);
//start the serial communication for debugging purposes if needed
// Serial.begin(9600);
// Serial.println("Serial Communication started");
}
void loop() {
// put your main code here, to run repeatedly:
switch (turn)
{
case IntinialState:
turnTrafficLedON(IntinialState, IntinialStateColor); delay(WaitingTime); turn = TrafficLedRoadD; break; case TrafficLedRoadD: turnTrafficLedON(TrafficLedRoadBC, red); turnTrafficLedON(TrafficLedRoadA, red); turnTrafficLedON(TrafficLedRoadD, green); delay(GreenTime); turnTrafficLedON(TrafficLedRoadBC, red); turnTrafficLedON(TrafficLedRoadA, red); turnTrafficLedON(TrafficLedRoadD, yellow); delay(YellowTime); turnTrafficLedON(TrafficLedRoadBC, red); turnTrafficLedON(TrafficLedRoadA, red); turnTrafficLedON(TrafficLedRoadD, red); delay(SecurityTime); turn = TrafficLedRoadA; break; case TrafficLedRoadA: turnTrafficLedON(TrafficLedRoadBC, red); turnTrafficLedON(TrafficLedRoadD, red); turnTrafficLedON(TrafficLedRoadA, green); delay(GreenTime); turnTrafficLedON(TrafficLedRoadBC, red); turnTrafficLedON(TrafficLedRoadD, red); turnTrafficLedON(TrafficLedRoadA, yellow); delay(YellowTime); turnTrafficLedON(TrafficLedRoadBC, red); turnTrafficLedON(TrafficLedRoadA, red); turnTrafficLedON(TrafficLedRoadD, red); delay(SecurityTime); turn = TrafficLedRoadBC; break; case TrafficLedRoadBC: turnTrafficLedON(TrafficLedRoadA, red); turnTrafficLedON(TrafficLedRoadD, red); turnTrafficLedON(TrafficLedRoadBC, green); delay(GreenTime); turnTrafficLedON(TrafficLedRoadA, red); turnTrafficLedON(TrafficLedRoadD, red); turnTrafficLedON(TrafficLedRoadBC, yellow); delay(YellowTime); turnTrafficLedON(TrafficLedRoadBC, red); turnTrafficLedON(TrafficLedRoadA, red); turnTrafficLedON(TrafficLedRoadD, red); delay(SecurityTime); turn = TrafficLedRoadD; break; default: turnTrafficLedON(ERRORLIGHTS, ERRORLIGHTS); break;
}
}
//define the work of the functions declared in the beginning of the sketch
void turnTrafficLedON (int TrafficLedNumber, int color)
{
//InitialSate
if (TrafficLedNumber == IntinialState && color == IntinialStateColor) // The system is Up for the first time.
{
//All the Traffic Leds must be RED and the rest colors OFF
//Turn Red Lights ON for all the traffic lights digitalWrite(TLAR, HIGH); digitalWrite(TLBCR, HIGH); digitalWrite(TLDR, HIGH); //Turn Yellow Lights OFF for all the traffic Lights digitalWrite(TLAY, LOW); digitalWrite(TLBCY, LOW); digitalWrite(TLDY, LOW); //Turn Green Lights OFF for all the traffic Lights digitalWrite(TLAG, LOW); digitalWrite(TLBCG, LOW); digitalWrite(TLDG, LOW);
}
//RED
if (TrafficLedNumber == TrafficLedRoadA && color == red) // The RED traffic lights on RoadA must be turned ON
{
digitalWrite(TLAG, LOW);
digitalWrite(TLAY, LOW);
digitalWrite(TLAR, HIGH);
}
if (TrafficLedNumber == TrafficLedRoadBC && color == red) // The RED traffic lights on RoadB & Road C must be turned ON
{
digitalWrite(TLBCG, LOW);
digitalWrite(TLBCY, LOW);
digitalWrite(TLBCR, HIGH);
}
if (TrafficLedNumber == TrafficLedRoadD && color == red) // The RED traffic lights on RoadD must be turned ON
{
digitalWrite(TLDG, LOW);
digitalWrite(TLDY, LOW);
digitalWrite(TLDR, HIGH);
}
//YELLOW
if (TrafficLedNumber == TrafficLedRoadA && color == yellow) // The YELLOW traffic lights on RoadA must be turned ON
{
digitalWrite(TLAG, LOW);
digitalWrite(TLAR, LOW);
digitalWrite(TLAY, HIGH);
}
if (TrafficLedNumber == TrafficLedRoadBC && color == yellow) // The YELLOW traffic lights on RoadB & Road C must be turned ON
{
digitalWrite(TLBCG, LOW);
digitalWrite(TLBCR, LOW);
digitalWrite(TLBCY, HIGH);
}
if (TrafficLedNumber == TrafficLedRoadD && color == yellow) // The YELLOW traffic lights on RoadD must be turned ON
{
digitalWrite(TLDG, LOW);
digitalWrite(TLDR, LOW);
digitalWrite(TLDY, HIGH);
}
//GREEN
if (TrafficLedNumber == TrafficLedRoadA && color == green) // The GREEN traffic lights on RoadA must be turned ON
{
digitalWrite(TLAY, LOW);
digitalWrite(TLAR, LOW);
digitalWrite(TLAG, HIGH);
}
if (TrafficLedNumber == TrafficLedRoadBC && color == green) // The GREEN traffic lights on RoadB & Road C must be turned ON
{
digitalWrite(TLBCY, LOW);
digitalWrite(TLBCR, LOW);
digitalWrite(TLBCG, HIGH);
}
if (TrafficLedNumber == TrafficLedRoadD && color == green) // The GREEN traffic lights on RoadD must be turned ON
{
digitalWrite(TLDY, LOW);
digitalWrite(TLDR, LOW);
digitalWrite(TLDG, HIGH);
}
//ERROR VALUES
if (TrafficLedNumber == ERRORLIGHTS && color == ERRORLIGHTS) // ERROR!! The YELLOW LIGHTS will Blink for 3 times
{
//Make sure all the LIGHTS are OFF
//YELLOW OFF digitalWrite(TLAY, HIGH); digitalWrite(TLBCY, HIGH); digitalWrite(TLDY, HIGH); //RED OFF digitalWrite(TLAR, HIGH); digitalWrite(TLBCR, HIGH); digitalWrite(TLDR, HIGH); //GREEN OFF digitalWrite(TLAG, HIGH); digitalWrite(TLBCG, HIGH); digitalWrite(TLDG, HIGH); for (int i=0; i<ERRORLIGHTSTIMEREPEAT; i++) //BLINK The YELLOW LIGHTS indicating an error { digitalWrite(TLAY, HIGH); digitalWrite(TLBCY, HIGH); digitalWrite(TLDY, HIGH); delay(ERRORLIGHTSTIME); digitalWrite(TLAY, LOW); digitalWrite(TLBCY, LOW); digitalWrite(TLDY, LOW); }
}
}Third Part: Add a Control Room
Traffic Light Arduino Code:
#include <SoftwareSerial.h>
//define RX and TX pins
define RX A0
define TX A1
//define the codes to be sent
define HelloMessage 50 //This is sent when the arduino is ON
//define codes:
define S0 1 //Initial State
define S1 2 //Green Traffic Light for Road D & Red Traffic Light for Road BC & A
define S2 3 //Yellow Traffic Light for Road D & Red Traffic Light for Road BC & A
define S3 4 //Red Traffic Light for Road D & Red Traffic Light for Road BC & A
define S4 5 //Green Traffic Light for Road A & Red Traffic Light for Road BC & D
define S5 6 //Yellow Traffic Light for Road A & Red Traffic Light for Road BC & D
define S6 7 //Red Traffic Light for Road A & Red Traffic Light for Road BC & D
define S7 8 //Green Traffic Light for Road BC & Red Traffic Light for Road D & A
define S8 9 //Yellow Traffic Light for Road BC & Red Traffic Light for Road D & A
define S9 10 //Red Traffic Light for Road BC & Red Traffic Light for Road D & A
define SE 100 //Error State
//define the software serial: S using RX (A0) and TX (A1)
SoftwareSerial s(RX,TX); //(RX = A0, TX= A1)
define TLAR 3 // RED Traffic Light for Road A
define TLAY 4 // Yellow Traffic Light for Road A
define TLAG 5 // Green Traffic Light for Road A
define TLBCR 6 // RED Traffic Light for Road B & Road C
define TLBCY 7 // Yellow Traffic Light for Road B & Road C
define TLBCG 8 // Green Traffic Light for Road B & Road C
define TLDR 9 // RED Traffic Light for Road D
define TLDY 10 // Yellow Traffic Light for Road D
define TLDG 11 // Green Traffic Light for Road D
define TrafficLedRoadA 1 //This is the reference number for the traffic lights of road A
define TrafficLedRoadBC 2 //This is the reference number for the traffic lights of road B and C
define TrafficLedRoadD 3 //This is the reference number for the traffic lights of road D
define IntinialState 4 //This is the reference number for the initial State of the system
define red 10 //This is the reference number for the red color
define green 20 //This is the reference number for the green color
define yellow 30 //This is the reference number for the yellow color
define IntinialStateColor 50 //This is the reference number of the initiale state color lighted when the system in UP for the first time
define ERRORLIGHTS 404 //This is the reference number for the error State
define ERRORLIGHTSTIMEREPEAT 3 //This is the number of time the yellow lights will blink when there is an error
define ERRORLIGHTSTIME 500 //This is the delay time between each ON & OFF for the error lights
define WaitingTime 15000 //15 Seconds This is the time of the the red light will be ON or the GREEN light will be ON.
define GreenTime 10000 //10 Seconds is the green time (of the 9 total seconds)
define YellowTime 5000 //5 Seconds is the yellow time (of the 9 total seconds)
define SecurityTime 5000 //1 Second is the time to switch the green light to another traffic light. It's when all teh traffic lights are RED ON. For security purposes
int turn=IntinialState; //This variable is used to pass between the turns of the traffic lights
void turnTrafficLedON (int TrafficLedNumber, int colorNumber); // This function will light the specified color based on the traffic light given
/*
Example:
turnTrafficLedON(1, 10);
This will trun RED light ON in TrafficLedRoadA and turn Yellow and Green Lights OFF on the same TrafficLedRoadA
*/
//the turn is ROAD D, ROAD A, ROAD B & C
void setup() {
// put your setup code here, to run once:
s.begin(9600); //start the serial connection
delay(100); //wait 100 ms to give it time
s.write(HelloMessage); //send a Hello Message to the control Room.
delay(100);
//Define all the traffic lights as output - till now we don't have an input in this program
pinMode(TLAR, OUTPUT);
pinMode(TLAY, OUTPUT);
pinMode(TLAG, OUTPUT);
pinMode(TLBCR, OUTPUT);
pinMode(TLBCY, OUTPUT);
pinMode(TLBCG, OUTPUT);
pinMode(TLDR, OUTPUT);
pinMode(TLDY, OUTPUT);
pinMode(TLDG, OUTPUT);
//Turn OFF all the outputs
digitalWrite(TLAG, LOW);
digitalWrite(TLAY, LOW);
digitalWrite(TLAR, LOW);
digitalWrite(TLBCG, LOW);
digitalWrite(TLBCY, LOW);
digitalWrite(TLBCR, LOW);
digitalWrite(TLDG, LOW);
digitalWrite(TLDY, LOW);
digitalWrite(TLDR, LOW);
//start the serial communication for debugging purposes if needed
// Serial.begin(9600);
// Serial.println("Serial Communication started");
}
void loop() {
// put your main code here, to run repeatedly:
switch (turn)
{
case IntinialState:
turnTrafficLedON(IntinialState, IntinialStateColor); s.write(S0); delay(WaitingTime); turn = TrafficLedRoadD; break; case TrafficLedRoadD: turnTrafficLedON(TrafficLedRoadBC, red); turnTrafficLedON(TrafficLedRoadA, red); turnTrafficLedON(TrafficLedRoadD, green); s.write(S1); delay(GreenTime); turnTrafficLedON(TrafficLedRoadBC, red); turnTrafficLedON(TrafficLedRoadA, red); turnTrafficLedON(TrafficLedRoadD, yellow); s.write(S2); delay(YellowTime); turnTrafficLedON(TrafficLedRoadBC, red); turnTrafficLedON(TrafficLedRoadA, red); turnTrafficLedON(TrafficLedRoadD, red); s.write(S3); delay(SecurityTime); turn = TrafficLedRoadA; break; case TrafficLedRoadA: turnTrafficLedON(TrafficLedRoadBC, red); turnTrafficLedON(TrafficLedRoadD, red); turnTrafficLedON(TrafficLedRoadA, green); s.write(S4); delay(GreenTime); turnTrafficLedON(TrafficLedRoadBC, red); turnTrafficLedON(TrafficLedRoadD, red); turnTrafficLedON(TrafficLedRoadA, yellow); s.write(S5); delay(YellowTime); turnTrafficLedON(TrafficLedRoadBC, red); turnTrafficLedON(TrafficLedRoadA, red); turnTrafficLedON(TrafficLedRoadD, red); s.write(S6); delay(SecurityTime); turn = TrafficLedRoadBC; break; case TrafficLedRoadBC: turnTrafficLedON(TrafficLedRoadA, red); turnTrafficLedON(TrafficLedRoadD, red); turnTrafficLedON(TrafficLedRoadBC, green); s.write(S7); delay(GreenTime); turnTrafficLedON(TrafficLedRoadA, red); turnTrafficLedON(TrafficLedRoadD, red); turnTrafficLedON(TrafficLedRoadBC, yellow); s.write(S8); delay(YellowTime); turnTrafficLedON(TrafficLedRoadBC, red); turnTrafficLedON(TrafficLedRoadA, red); turnTrafficLedON(TrafficLedRoadD, red); s.write(S9); delay(SecurityTime); turn = TrafficLedRoadD; break; default: turnTrafficLedON(ERRORLIGHTS, ERRORLIGHTS); s.write(SE); break;
}
}
//define the work of the functions declared in the beginning of the sketch
void turnTrafficLedON (int TrafficLedNumber, int color)
{
//InitialSate
if (TrafficLedNumber == IntinialState && color == IntinialStateColor) // The system is Up for the first time.
{
//All the Traffic Leds must be RED and the rest colors OFF
//Turn Red Lights ON for all the traffic lights digitalWrite(TLAR, HIGH); digitalWrite(TLBCR, HIGH); digitalWrite(TLDR, HIGH); //Turn Yellow Lights OFF for all the traffic Lights digitalWrite(TLAY, LOW); digitalWrite(TLBCY, LOW); digitalWrite(TLDY, LOW); //Turn Green Lights OFF for all the traffic Lights digitalWrite(TLAG, LOW); digitalWrite(TLBCG, LOW); digitalWrite(TLDG, LOW);
}
//RED
if (TrafficLedNumber == TrafficLedRoadA && color == red) // The RED traffic lights on RoadA must be turned ON
{
digitalWrite(TLAG, LOW);
digitalWrite(TLAY, LOW);
digitalWrite(TLAR, HIGH);
}
if (TrafficLedNumber == TrafficLedRoadBC && color == red) // The RED traffic lights on RoadB & Road C must be turned ON
{
digitalWrite(TLBCG, LOW);
digitalWrite(TLBCY, LOW);
digitalWrite(TLBCR, HIGH);
}
if (TrafficLedNumber == TrafficLedRoadD && color == red) // The RED traffic lights on RoadD must be turned ON
{
digitalWrite(TLDG, LOW);
digitalWrite(TLDY, LOW);
digitalWrite(TLDR, HIGH);
}
//YELLOW
if (TrafficLedNumber == TrafficLedRoadA && color == yellow) // The YELLOW traffic lights on RoadA must be turned ON
{
digitalWrite(TLAG, LOW);
digitalWrite(TLAR, LOW);
digitalWrite(TLAY, HIGH);
}
if (TrafficLedNumber == TrafficLedRoadBC && color == yellow) // The YELLOW traffic lights on RoadB & Road C must be turned ON
{
digitalWrite(TLBCG, LOW);
digitalWrite(TLBCR, LOW);
digitalWrite(TLBCY, HIGH);
}
if (TrafficLedNumber == TrafficLedRoadD && color == yellow) // The YELLOW traffic lights on RoadD must be turned ON
{
digitalWrite(TLDG, LOW);
digitalWrite(TLDR, LOW);
digitalWrite(TLDY, HIGH);
}
//GREEN
if (TrafficLedNumber == TrafficLedRoadA && color == green) // The GREEN traffic lights on RoadA must be turned ON
{
digitalWrite(TLAY, LOW);
digitalWrite(TLAR, LOW);
digitalWrite(TLAG, HIGH);
}
if (TrafficLedNumber == TrafficLedRoadBC && color == green) // The GREEN traffic lights on RoadB & Road C must be turned ON
{
digitalWrite(TLBCY, LOW);
digitalWrite(TLBCR, LOW);
digitalWrite(TLBCG, HIGH);
}
if (TrafficLedNumber == TrafficLedRoadD && color == green) // The GREEN traffic lights on RoadD must be turned ON
{
digitalWrite(TLDY, LOW);
digitalWrite(TLDR, LOW);
digitalWrite(TLDG, HIGH);
}
//ERROR VALUES
if (TrafficLedNumber == ERRORLIGHTS && color == ERRORLIGHTS) // ERROR!! The YELLOW LIGHTS will Blink for 3 times
{
//Make sure all the LIGHTS are OFF
//YELLOW OFF digitalWrite(TLAY, HIGH); digitalWrite(TLBCY, HIGH); digitalWrite(TLDY, HIGH); //RED OFF digitalWrite(TLAR, HIGH); digitalWrite(TLBCR, HIGH); digitalWrite(TLDR, HIGH); //GREEN OFF digitalWrite(TLAG, HIGH); digitalWrite(TLBCG, HIGH); digitalWrite(TLDG, HIGH); for (int i=0; i<ERRORLIGHTSTIMEREPEAT; i++) //BLINK The YELLOW LIGHTS indicating an error { digitalWrite(TLAY, HIGH); digitalWrite(TLBCY, HIGH); digitalWrite(TLDY, HIGH); delay(ERRORLIGHTSTIME); digitalWrite(TLAY, LOW); digitalWrite(TLBCY, LOW); digitalWrite(TLDY, LOW); }
}
}Monitoring Room Arduino Code:
#include <SoftwareSerial.h>
//define RX and TX pins
define RX A1
define TX A0
//define the codes to be sent
define HelloMessage 50 //This is sent when the arduino is ON
//define codes:
define S0 1 //Initial State
define S1 2 //Green Traffic Light for Road D & Red Traffic Light for Road BC & A
define S2 3 //Yellow Traffic Light for Road D & Red Traffic Light for Road BC & A
define S3 4 //Red Traffic Light for Road D & Red Traffic Light for Road BC & A
define S4 5 //Green Traffic Light for Road A & Red Traffic Light for Road BC & D
define S5 6 //Yellow Traffic Light for Road A & Red Traffic Light for Road BC & D
define S6 7 //Red Traffic Light for Road A & Red Traffic Light for Road BC & D
define S7 8 //Green Traffic Light for Road BC & Red Traffic Light for Road D & A
define S8 9 //Yellow Traffic Light for Road BC & Red Traffic Light for Road D & A
define S9 10 //Red Traffic Light for Road BC & Red Traffic Light for Road D & A
define SE 100 //Error State
int HelloMessageStep1 = 0;
void checkdata(int ); //Function to check the received data
//define the software serial: S using RX (A0) and TX (A1)
SoftwareSerial s(RX,TX); //(RX = A1, TX= A0)
void setup() {
// put your setup code here, to run once:
Serial.begin(9600);
s.begin(9600); //start the serial connection
delay(100); //wait 100 ms to give it time
while(HelloMessageStep1 == 0)
{
if(s.available()>0)
{
checkdata(s.read());
HelloMessageStep1 = 1;
}
}
}
void loop() {
// put your main code here, to run repeatedly:
if(s.available()>0) { checkdata(s.read()); }
}
void checkdata(int data) //Function to check the received data
{
switch (data)
{
case 1:
Serial.println("Initial State");
break;
case 2: Serial.println(" "); Serial.println("State 1:"); Serial.println("Road D Green"); Serial.println("Road BC RED"); Serial.println("Road A RED"); Serial.println(" "); break; case 3: Serial.println(" "); Serial.println("State 2:"); Serial.println("Road D Yellow"); Serial.println("Road BC RED"); Serial.println("Road A RED"); Serial.println(" "); break; case 4: Serial.println(" "); Serial.println("State 3:"); Serial.println("Road D RED"); Serial.println("Road BC RED"); Serial.println("Road A RED"); Serial.println(" "); break; case 5: Serial.println(" "); Serial.println("State 4:"); Serial.println("Road A Green"); Serial.println("Road D RED"); Serial.println("Road BC RED"); Serial.println(" "); break; case 6: Serial.println(" "); Serial.println("State 5:"); Serial.println("Road A Yellow"); Serial.println("Road D RED"); Serial.println("Road BC RED"); Serial.println(" "); break; case 7: Serial.println(" "); Serial.println("State 6:"); Serial.println("Road A RED"); Serial.println("Road D RED"); Serial.println("Road BC RED"); Serial.println(" "); break; case 8: Serial.println(" "); Serial.println("State 7:"); Serial.println("Road BC Green"); Serial.println("Road A RED"); Serial.println("Road D RED"); Serial.println(" "); break; case 9: Serial.println(" "); Serial.println("State 8:"); Serial.println("Road BC Yellow"); Serial.println("Road A RED"); Serial.println("Road D RED"); Serial.println(" "); break; case 10: Serial.println(" "); Serial.println("State 9:"); Serial.println("Road BC RED"); Serial.println("Road A RED"); Serial.println("Road D RED"); Serial.println(" "); break; case 50: Serial.println(" "); Serial.println("Hello Message Received, System is UP"); Serial.println(" "); break; case 100: Serial.println(" "); Serial.println("ERROR ERROR ERROR ERROR"); Serial.println(" "); break;
}
}Fourth Part: Add Sensor for Road D
#include <SoftwareSerial.h>
//define RX and TX pins
#define RX A0
#define TX A1
//define the codes to be sent
#define HelloMessage 50 //This is sent when the arduino is ON
//define codes:
#define S0 1 //Initial State
#define S1 2 //Green Traffic Light for Road D & Red Traffic Light for Road BC & A
#define S2 3 //Yellow Traffic Light for Road D & Red Traffic Light for Road BC & A
#define S3 4 //Red Traffic Light for Road D & Red Traffic Light for Road BC & A
#define S4 5 //Green Traffic Light for Road A & Red Traffic Light for Road BC & D
#define S5 6 //Yellow Traffic Light for Road A & Red Traffic Light for Road BC & D
#define S6 7 //Red Traffic Light for Road A & Red Traffic Light for Road BC & D
#define S7 8 //Green Traffic Light for Road BC & Red Traffic Light for Road D & A
#define S8 9 //Yellow Traffic Light for Road BC & Red Traffic Light for Road D & A
#define S9 10 //Red Traffic Light for Road BC & Red Traffic Light for Road D & A
#define SE 100 //Error State
//define the software serial: S using RX (A0) and TX (A1)
SoftwareSerial s(RX,TX); //(RX = A0, TX= A1)
#define TLAR 3 // RED Traffic Light for Road A
#define TLAY 4 // Yellow Traffic Light for Road A
#define TLAG 5 // Green Traffic Light for Road A
#define TLBCR 6 // RED Traffic Light for Road B & Road C
#define TLBCY 7 // Yellow Traffic Light for Road B & Road C
#define TLBCG 8 // Green Traffic Light for Road B & Road C
#define TLDR 9 // RED Traffic Light for Road D
#define TLDY 10 // Yellow Traffic Light for Road D
#define TLDG 11 // Green Traffic Light for Road D
#define SensorRoadD 12 //The sensor of ROAD D is Connected to the pin number 12
#define TrafficLedRoadA 1 //This is the reference number for the traffic lights of road A
#define TrafficLedRoadBC 2 //This is the reference number for the traffic lights of road B and C
#define TrafficLedRoadD 3 //This is the reference number for the traffic lights of road D
#define IntinialState 4 //This is the reference number for the initial State of the system
#define red 10 //This is the reference number for the red color
#define green 20 //This is the reference number for the green color
#define yellow 30 //This is the reference number for the yellow color
#define IntinialStateColor 50 //This is the reference number of the initiale state color lighted when the system in UP for the first time
#define ERRORLIGHTS 404 //This is the reference number for the error State
#define ERRORLIGHTSTIMEREPEAT 3 //This is the number of time the yellow lights will blink when there is an error
#define ERRORLIGHTSTIME 500 //This is the delay time between each ON & OFF for the error lights
#define WaitingTime 15000 //15 Seconds This is the time of the the red light will be ON or the GREEN light will be ON.
#define GreenTime 10000 //10 Seconds is the green time (of the 9 total seconds)
#define YellowTime 5000 //5 Seconds is the yellow time (of the 9 total seconds)
#define SecurityTime 5000 //1 Second is the time to switch the green light to another traffic light. It's when all teh traffic lights are RED ON. For security purposes
int turn=IntinialState; //This variable is used to pass between the turns of the traffic lights
void turnTrafficLedON (int TrafficLedNumber, int colorNumber); // This function will light the specified color based on the traffic light given
/*
Example:
turnTrafficLedON(1, 10);
This will trun RED light ON in TrafficLedRoadA and turn Yellow and Green Lights OFF on the same TrafficLedRoadA
*/
//the turn is ROAD D, ROAD A, ROAD B & C
int isThereAnyoneOnRoadD();
int PreviousTurn = TrafficLedRoadA; //A variable to store the previous trun
void setup() {
// put your setup code here, to run once:
s.begin(9600); //start the serial connection
delay(100); //wait 100 ms to give it time
s.write(HelloMessage); //send a Hello Message to the control Room.
delay(100);
//Define all the traffic lights as output - till now we don't have an input in this program
pinMode(TLAR, OUTPUT);
pinMode(TLAY, OUTPUT);
pinMode(TLAG, OUTPUT);
pinMode(TLBCR, OUTPUT);
pinMode(TLBCY, OUTPUT);
pinMode(TLBCG, OUTPUT);
pinMode(TLDR, OUTPUT);
pinMode(TLDY, OUTPUT);
pinMode(TLDG, OUTPUT);
pinMode(SensorRoadD, INPUT);
//Turn OFF all the outputs
digitalWrite(TLAG, LOW);
digitalWrite(TLAY, LOW);
digitalWrite(TLAR, LOW);
digitalWrite(TLBCG, LOW);
digitalWrite(TLBCY, LOW);
digitalWrite(TLBCR, LOW);
digitalWrite(TLDG, LOW);
digitalWrite(TLDY, LOW);
digitalWrite(TLDR, LOW);
//start the serial communication for debugging purposes if needed
// Serial.begin(9600);
// Serial.println("Serial Communication started");
}
void loop() {
// put your main code here, to run repeatedly:
switch (turn)
{
case IntinialState:
turnTrafficLedON(IntinialState, IntinialStateColor);
s.write(S0);
delay(WaitingTime);
turn = TrafficLedRoadD;
break;
case TrafficLedRoadD:
turnTrafficLedON(TrafficLedRoadBC, red);
turnTrafficLedON(TrafficLedRoadA, red);
turnTrafficLedON(TrafficLedRoadD, green);
s.write(S1);
delay(GreenTime);
turnTrafficLedON(TrafficLedRoadBC, red);
turnTrafficLedON(TrafficLedRoadA, red);
turnTrafficLedON(TrafficLedRoadD, yellow);
s.write(S2);
delay(YellowTime);
turnTrafficLedON(TrafficLedRoadBC, red);
turnTrafficLedON(TrafficLedRoadA, red);
turnTrafficLedON(TrafficLedRoadD, red);
s.write(S3);
delay(SecurityTime);
turn = PreviousTurn;
break;
case TrafficLedRoadA:
if(isThereAnyoneOnRoadD()==1)
{
PreviousTurn = TrafficLedRoadA;
turn = TrafficLedRoadD;
break;
}
else
{
turnTrafficLedON(TrafficLedRoadBC, red);
turnTrafficLedON(TrafficLedRoadD, red);
turnTrafficLedON(TrafficLedRoadA, green);
s.write(S4);
delay(GreenTime);
turnTrafficLedON(TrafficLedRoadBC, red);
turnTrafficLedON(TrafficLedRoadD, red);
turnTrafficLedON(TrafficLedRoadA, yellow);
s.write(S5);
delay(YellowTime);
turnTrafficLedON(TrafficLedRoadBC, red);
turnTrafficLedON(TrafficLedRoadA, red);
turnTrafficLedON(TrafficLedRoadD, red);
s.write(S6);
delay(SecurityTime);
turn = TrafficLedRoadBC;
break;
}
case TrafficLedRoadBC:
if(isThereAnyoneOnRoadD()==1)
{
PreviousTurn = TrafficLedRoadBC;
turn = TrafficLedRoadD;
break;
}
else
{
turnTrafficLedON(TrafficLedRoadA, red);
turnTrafficLedON(TrafficLedRoadD, red);
turnTrafficLedON(TrafficLedRoadBC, green);
s.write(S7);
delay(GreenTime);
turnTrafficLedON(TrafficLedRoadA, red);
turnTrafficLedON(TrafficLedRoadD, red);
turnTrafficLedON(TrafficLedRoadBC, yellow);
s.write(S8);
delay(YellowTime);
turnTrafficLedON(TrafficLedRoadBC, red);
turnTrafficLedON(TrafficLedRoadA, red);
turnTrafficLedON(TrafficLedRoadD, red);
s.write(S9);
delay(SecurityTime);
turn = TrafficLedRoadA;
break;
}
default:
turnTrafficLedON(ERRORLIGHTS, ERRORLIGHTS);
s.write(SE);
break;
}
}
//define the work of the functions declared in the beginning of the sketch
void turnTrafficLedON (int TrafficLedNumber, int color)
{
//InitialSate
if (TrafficLedNumber == IntinialState && color == IntinialStateColor) // The system is Up for the first time.
{
//All the Traffic Leds must be RED and the rest colors OFF
//Turn Red Lights ON for all the traffic lights
digitalWrite(TLAR, HIGH);
digitalWrite(TLBCR, HIGH);
digitalWrite(TLDR, HIGH);
//Turn Yellow Lights OFF for all the traffic Lights
digitalWrite(TLAY, LOW);
digitalWrite(TLBCY, LOW);
digitalWrite(TLDY, LOW);
//Turn Green Lights OFF for all the traffic Lights
digitalWrite(TLAG, LOW);
digitalWrite(TLBCG, LOW);
digitalWrite(TLDG, LOW);
}
//RED
if (TrafficLedNumber == TrafficLedRoadA && color == red) // The RED traffic lights on RoadA must be turned ON
{
digitalWrite(TLAG, LOW);
digitalWrite(TLAY, LOW);
digitalWrite(TLAR, HIGH);
}
if (TrafficLedNumber == TrafficLedRoadBC && color == red) // The RED traffic lights on RoadB & Road C must be turned ON
{
digitalWrite(TLBCG, LOW);
digitalWrite(TLBCY, LOW);
digitalWrite(TLBCR, HIGH);
}
if (TrafficLedNumber == TrafficLedRoadD && color == red) // The RED traffic lights on RoadD must be turned ON
{
digitalWrite(TLDG, LOW);
digitalWrite(TLDY, LOW);
digitalWrite(TLDR, HIGH);
}
//YELLOW
if (TrafficLedNumber == TrafficLedRoadA && color == yellow) // The YELLOW traffic lights on RoadA must be turned ON
{
digitalWrite(TLAG, LOW);
digitalWrite(TLAR, LOW);
digitalWrite(TLAY, HIGH);
}
if (TrafficLedNumber == TrafficLedRoadBC && color == yellow) // The YELLOW traffic lights on RoadB & Road C must be turned ON
{
digitalWrite(TLBCG, LOW);
digitalWrite(TLBCR, LOW);
digitalWrite(TLBCY, HIGH);
}
if (TrafficLedNumber == TrafficLedRoadD && color == yellow) // The YELLOW traffic lights on RoadD must be turned ON
{
digitalWrite(TLDG, LOW);
digitalWrite(TLDR, LOW);
digitalWrite(TLDY, HIGH);
}
//GREEN
if (TrafficLedNumber == TrafficLedRoadA && color == green) // The GREEN traffic lights on RoadA must be turned ON
{
digitalWrite(TLAY, LOW);
digitalWrite(TLAR, LOW);
digitalWrite(TLAG, HIGH);
}
if (TrafficLedNumber == TrafficLedRoadBC && color == green) // The GREEN traffic lights on RoadB & Road C must be turned ON
{
digitalWrite(TLBCY, LOW);
digitalWrite(TLBCR, LOW);
digitalWrite(TLBCG, HIGH);
}
if (TrafficLedNumber == TrafficLedRoadD && color == green) // The GREEN traffic lights on RoadD must be turned ON
{
digitalWrite(TLDY, LOW);
digitalWrite(TLDR, LOW);
digitalWrite(TLDG, HIGH);
}
//ERROR VALUES
if (TrafficLedNumber == ERRORLIGHTS && color == ERRORLIGHTS) // ERROR!! The YELLOW LIGHTS will Blink for 3 times
{
//Make sure all the LIGHTS are OFF
//YELLOW OFF
digitalWrite(TLAY, HIGH);
digitalWrite(TLBCY, HIGH);
digitalWrite(TLDY, HIGH);
//RED OFF
digitalWrite(TLAR, HIGH);
digitalWrite(TLBCR, HIGH);
digitalWrite(TLDR, HIGH);
//GREEN OFF
digitalWrite(TLAG, HIGH);
digitalWrite(TLBCG, HIGH);
digitalWrite(TLDG, HIGH);
for (int i=0; i<ERRORLIGHTSTIMEREPEAT; i++) //BLINK The YELLOW LIGHTS indicating an error
{
digitalWrite(TLAY, HIGH);
digitalWrite(TLBCY, HIGH);
digitalWrite(TLDY, HIGH);
delay(ERRORLIGHTSTIME);
digitalWrite(TLAY, LOW);
digitalWrite(TLBCY, LOW);
digitalWrite(TLDY, LOW);
}
}
}
int isThereAnyoneOnRoadD()
{
if (digitalRead(SensorRoadD) == 1)
{
return 1;
}
else
{
return 0;
}
} 
