// === Brandon Cherry ====
// Module 7 Course project IOT MQTT
#include <WiFi.h> // WiFi header file
#include <PubSubClient.h> // MQTT publish and subscribe header file
#include <Wire.h> // I2C header file
#include <LiquidCrystal_I2C.h> // I2C lcd header file
const char* ssid = "Wokwi-GUEST"; // This is the access point to your wireless network.
const char* password = ""; // This is the password to the SSID. For the smart mini router
const char* mqttServer = "test.mosquitto.org"; // This is the free MQTT broker we will use.
int port = 1883; // MQTT brokers listen to port 1883 by default
String stMac; // C string used for convenience of comparisons.
char mac[50]; // C char array used to hold the MAC address of your ESP32 microconroller
char clientId[50]; // This client ID is used to identify the user accessing the MQTT broker.
// For our test.mosquitto.org broker, we just generate a random user client ID
WiFiClient espClient; // instantiate the WiFi client object
PubSubClient client(espClient); // instantiate the publish subscribe client object
LiquidCrystal_I2C lcd(0x27,16,2); //set the LCD address to 0x27 for a 16 chars and 2-line display
// if it does not work then try 0x3F, if both addresses do not work then run the scan code
const int redLightNorthSouth = 14; // The red LED NS is wired to ESP32 board pin GPIO 14
const int yellowLightNorthSouth = 12; // The yellow LED NS is wired to ESP32 board pin GPIO 12
const int greenLightNorthSouth = 13; // The green LED NS is wired to ESP32 board pin GPIO 13
const int redLightEastWest = 25; // The red LED EW is wired to ESP32 pin GPIO 25
const int yellowLightEastWest = 26; // The yellow LED EW is wired to ESP32 board pin GPIO 26
const int greenLightEastWest = 27; // The green LED EW is wired to ESP32 board pin GPIO 27
int crossWalkButtonState = 1 ; // Variable will store the state of the crosswalk button
const int crossWalkButton = 19; // Cross Walk button pin is GPIO 19
const int emergencyBlueLED = 16; // The blue LED is wired to ESP32 board pin GPIO 16
const int buzzerPin = 32; // Active Buzzer pin is GPIO 32
int loopCount; // Variable will keep count of the number of times the light pattern repeats
int secondsLeft; // counter to keep track of number of seconds left for crossing intersection
int iotControl = 0; // Variable will be used to switch between emergency and normal operations of
// traffic controller
void setup() {
Serial.begin(115200); // set baud rate of serial monitor to 115200 bits per second
randomSeed(analogRead(0)); // seed the random() function
delay(10); // wait 10 milliseconds
Serial.println(); // start by skipping a line on the serial monitor
Serial.print("Connecting to "); // display message connection to
Serial.println(ssid); // display SSID name
wifiConnect(); // initiate connection to WiFi access point
Serial.println(""); // Skip a line on serial monitor
Serial.println("WiFi connected"); // display message WiFi connected
Serial.println("IP address: "); // display message IP Address
Serial.println(WiFi.localIP()); // display local IP address
Serial.println(WiFi.macAddress()); // display MAC address
stMac = WiFi.macAddress(); // copy MAC address
stMac.replace(":", "_"); // replace the underscores with colons
Serial.println(stMac); // display the cleaned up MAC address
client.setServer(mqttServer, port); // Connect to MQTT server test.mosquitto.org
client.setCallback(callback); // set callback function for handling MQTT messages
pinMode(crossWalkButton, INPUT_PULLUP); // 0 = button is pressed, 1 = button not pressed
attachInterrupt(crossWalkButton, buttonPressed, FALLING); // set up crosswalk button to trigger
// interrupts on falling edges
pinMode(redLightNorthSouth, OUTPUT); // initialize digital pin 14 (Red LED NS) as an output.
pinMode(yellowLightNorthSouth, OUTPUT); // initialize digital pin 12 (Yellow LED NS) as an output.
pinMode(greenLightNorthSouth, OUTPUT); // initialize digital pin 13 (green LED NS) as an output.
pinMode(redLightEastWest, OUTPUT); // initialize digital pin 25 (Red LED EW) as an output.
pinMode(yellowLightEastWest, OUTPUT); // initialize digital pin 26 (Yellow LED EW) as an output.
pinMode(greenLightEastWest, OUTPUT); // initialize digital pin 27 (Green LED EW) as an output.
pinMode(emergencyBlueLED, OUTPUT); // initialize digital pin 16 (Blue emergency LED) as an output.
pinMode(buzzerPin, OUTPUT); // initialize digital pin 32 (Active buzzer) as an output.
tone(buzzerPin, 0); //turn buzzer off
lcd.init(); // initialize the lcd
lcd.backlight(); // turn on backlight of lcd
lcd.setCursor(0,0); // set cursor to column # 1 and Row # 1
lcd.print("=== CEIS-114 ==="); // display this message
}
void wifiConnect() {
WiFi.mode(WIFI_STA); // set WiFi mode to STA
WiFi.begin(ssid, password); // connect WiFi using SSID and password
while (WiFi.status() != WL_CONNECTED) { // As long as WiFi connection is not established
delay(500); // wait half a second
Serial.print("."); // display period on serial monitor
}
}
void mqttReconnect() { // If connection to MQTT broker is lost. Call this function
while (!client.connected()) { // As long as connection is not established
Serial.print("Attempting MQTT connection..."); // Display message attempting MQTT connection
long r = random(1000); // Generate a long integer
sprintf(clientId, "clientId-%ld", r); // display client ID
if (client.connect(clientId)) { // Is connection to MQTT broker is established
Serial.print(clientId); // Display client ID on serial monitor
Serial.println(" connected"); // Display connected message on serial monitor
client.subscribe("LED"); // Subscribe to topic LED.
}
else { // If connection to MQTT broker has failed
Serial.print("failed, rc="); // Display failed
Serial.print(client.state()); // Display client ID for failed connection
Serial.println(" try again in 5 seconds"); // Display message try again in 5 seconds
delay(5000); // Wait 5 seconds
}
}
}
void callback(char* topic, byte* message, unsigned int length) { // Callback function for handling MQTT
//messages
String stMessage; // Create C string object
for (int i = 0; i < length; i++) { // Run a loop that will process all the characters of the MQTT message
stMessage += (char)message[i]; // Add character to the C string one at a time
}
if (String(topic) == "LED") { // Check if the topic received is LED
if(stMessage == "ON"){ // Check if the message is ON
iotControl = 1; // Set iotControl variable to high
}
else if(stMessage == "OFF"){ // if the message received is OFF
iotControl = 0; // Set iotControl variable to low
}
}
}
void loop() { // loop() function
if (!client.connected()) { // If the client is not connected to MQTT broker
mqttReconnect(); // Try reconnecting
}
while( iotControl == 0 ) { // As long as variable iotControl is low. Run the normal traffic light
lcd.setCursor(0,1); // set the cursor to column 1, line 2
lcd.print("= Do Not Walk! ="); // display Walk tmessage to the LCD.
Serial.println(" == Do Not Walk == "); // display Do Not Walk message on serial monitor
digitalWrite(emergencyBlueLED, LOW); // This should turn off the Remergency blue LED
if (crossWalkButtonState == 0 ){ // if crosswalk button is pressed
digitalWrite(yellowLightNorthSouth , LOW); // This should turn off the Yellow LED NS
digitalWrite(greenLightNorthSouth, LOW); // This should turn off the Green LED EW
digitalWrite(yellowLightEastWest , LOW); // This should turn off the Yellow LED NS
digitalWrite(greenLightEastWest, LOW); // This should turn off the Yellow LED EW
// display Walk message on the LCD
lcd.setCursor(0,1); // set the cursor to column 1, line 2
lcd.print(" == Walk! == "); // display Walk tmessage to the LCD.
secondsLeft = 15; // Set the delay for crossing the intersection at 15 seconds.
while( secondsLeft > 0 ){ // As long as the timer hasn’t run up yet
if( secondsLeft >= 10){ // If the timer has a value with 2 digits
Serial.print(" == Walk == "); // display message Walk on serial monitor
Serial.println(secondsLeft); // display timer value
lcd.setCursor(14 ,1); // set the cursor to column 15, line 2
lcd.print(secondsLeft); // display number of seconds left 2
}
else {
Serial.print(" == Walk == "); // If timer has a single digit. Line up the numbers
Serial.println(secondsLeft); // Display the timer value
lcd.setCursor(14,1); // set the cursor to column 15, line 2
lcd.print(" "); // clear anything on the last 2 columns
lcd.setCursor(15,1); // set the cursor to column 15, line 2
lcd.print(secondsLeft); // display number of seconds left
}
digitalWrite(redLightNorthSouth, HIGH); // This should turn on the RED LED NS
digitalWrite(redLightEastWest, HIGH); // This should turn on the RED Yellow LED NS
tone(buzzerPin, 200);
delay(500); // wait 0.5 seconds
digitalWrite(redLightNorthSouth, LOW); // This should turn off the Red LED NS
digitalWrite(redLightEastWest, LOW); // This should turn off the Red LED EW
tone(buzzerPin, 250);
delay(500); // wait 0.5 seconds
secondsLeft -= 1; // Decrement timer count by one second
client.loop(); // Check if new MQTT messages have been published
if( iotControl == 1){ // If iotControl variable is high.
break; // Break out of the while() loop
}
} // end of while() loop
crossWalkButtonState = 1 ; // Set the crosswalk variable high. This should get us out of the cross
// walk routine
} // end of if statement
else {
// The next three lines of code turn on the red LED NS
digitalWrite(redLightNorthSouth, HIGH); // This should turn on the Red LED NS
digitalWrite(yellowLightNorthSouth , LOW); // This should turn off the Yellow LED NS
digitalWrite(greenLightNorthSouth, LOW); // This should turn off the Green LED NS
digitalWrite(redLightEastWest, HIGH); // This should turn on the Red LED EW
digitalWrite(yellowLightEastWest , LOW); // This should turn off the Yellow LED EW
digitalWrite(greenLightEastWest, LOW); // This should turn off the Green LED EW
client.loop(); // Check if new MQTT messages have been published
delay(1000);
if( iotControl == 1){ // If iotControl variable is high.
break; // Break out of the while() loop
}
// The next three lines of code turn on the red Yellow LED NS
digitalWrite(redLightEastWest, LOW); // This should turn off the Red LED EW
digitalWrite(yellowLightEastWest , LOW); // This should turn off the Yellow LED EW
digitalWrite(greenLightEastWest, HIGH); // This should turn on the Green LED EW
delay(2000); // wait for 2 seconds
// The next three lines of client.loop(); // Check if new MQTT messages have been published
if( iotControl == 1){ // If iotControl variable is high.
break; // Break out of the while() loop
}
// code to turn on the red LED NS
digitalWrite(redLightNorthSouth, HIGH); // This should turn on the Red LED NS
digitalWrite(yellowLightNorthSouth , LOW); // This should turn off the Yellow LED NS
digitalWrite(greenLightNorthSouth, LOW); // This should turn off the Green LED NS
// The next three lines of code turn on the red Yellow LED NS
digitalWrite(redLightEastWest, LOW); // This should turn off the Red LED EW
digitalWrite(yellowLightEastWest , HIGH); // This should turn on the Yellow LED EW
digitalWrite(greenLightEastWest, LOW); // This should turn off the Green LED EW
delay(2000); // wait for 2 seconds
client.loop(); // Check if new MQTT messages have been published
if( iotControl == 1){ // If iotControl variable is high.
break; // Break out of the while() loop
}
// The next three lines of code turn on the red Yellow LED NS
digitalWrite(redLightEastWest, HIGH); // This should turn on the Red LED NS
digitalWrite(yellowLightEastWest , LOW); // This should turn off the Yellow LED NS
digitalWrite(greenLightEastWest, LOW); // This should turn off the Green LED NS
delay(1000); //Extended time for Red light#2 before the Green of the other side turns ON
client.loop(); // Check if new MQTT messages have been published
if( iotControl == 1){ // If iotControl variable is high.
break; // Break out of the while() loop
}
// The next three lines of code turn on the yellow LED NS
digitalWrite(redLightNorthSouth, LOW); //This should turn off the Red LED NS
digitalWrite(yellowLightNorthSouth , LOW); // This should turn off the Yellow LED NS
digitalWrite(greenLightNorthSouth, HIGH); // This should turn on the Green LED NS
delay(2000); // wait for 2 seconds
client.loop(); // Check if new MQTT messages have been published
if( iotControl == 1){ // If iotControl variable is high.
break; // Break out of the while() loop
}
// The next three lines of code turn on the yellow LED NS
digitalWrite(redLightNorthSouth, LOW); // This should turn off the Red LED NS
digitalWrite(yellowLightNorthSouth , HIGH); // This should turn on the Yellow LED NS
digitalWrite(greenLightNorthSouth, LOW); // This should turn off the Green LED NS
// The next three lines of code turn on the red Yellow LED NS
digitalWrite(redLightEastWest, HIGH); // This should turn on the Red LED EW
digitalWrite(yellowLightEastWest , LOW); // This should turn off the Yellow LED EW
digitalWrite(greenLightEastWest, LOW); // This should turn off the Green LED EW
delay(2000); // wait for 2 seconds
client.loop(); // Check if new MQTT messages have been published
if( iotControl == 1){ // If iotControl variable is high.
break; // Break out of the while() loop
}
}
} // end of while() loop
while( iotControl == 1){
lcd.setCursor(0,1); // set the cursor to column 1, line 2
lcd.println("= Emergency! =");
Serial.println("= Emergency! =");
digitalWrite(yellowLightNorthSouth , LOW); // This should turn off the Yellow LED NS
digitalWrite(greenLightNorthSouth, LOW); // This should turn off the Green LED NS
digitalWrite(yellowLightEastWest , LOW); // This should turn off the Yellow LED EW
digitalWrite(greenLightEastWest, LOW); // This should turn off the Yellow LED EW
digitalWrite(redLightNorthSouth, HIGH); // This should turn on the RED LED NS
digitalWrite(redLightEastWest, HIGH); // This should turn on the RED Yellow LED NS
digitalWrite(emergencyBlueLED, HIGH); // This should turn on the Remergency blue LED
tone(buzzerPin, 200); // This should turn on the active buzzer
delay(500);
digitalWrite(emergencyBlueLED, LOW); // This should turn off the Remergency blue LED
tone(buzzerPin, 0); // This should turn off the active buzzer
delay(500);
client.loop();
client.loop(); // Check if new MQTT messages have been published
if( iotControl == 1)
{ // If iotControl variable is high.
break; // Break out of the while() loop
}
}
client.loop(); // Check if new MQTT messages have been published one last time
}
void buttonPressed() // Function to handle any cross walk button presses
{
static unsigned long lastInterruptTime = 0; // Create variable for holding interrupt time
unsigned long interruptTime = millis(); // Store current time in milli-seconds
// If interrupts come faster than 200ms, assume it's a bounce and ignore
if (interruptTime - lastInterruptTime > 20)
{
crossWalkButtonState = 0; // Change the value of the variable that holds the state of the button
}
lastInterruptTime = interruptTime; // Save the timer
}