Smart parking using iot

[vamshi9189]

Hello,
I'm beginner in the field of iot
I'm trying to connect ultrasonic sensor with esp8266, Arduino and Mqtt.
This is my code

#include <NewPing.h>
#include <ESP8266WiFi.h>
#include<WiFiClient.h>
#include<PubSubClient.h>

void callback(chartopic,bytepayload,unsigned int length1);
void reconnect();
const charssid="xxxx ";
const charpassword="xxxxx";
const int trigPin=2;
const int echoPin=0;
long duration;
int distance;

unsigned long lastMillis=0;
const char*mqtt_server="Mqtt broker";
int mqtt_port=1883;
WiFiClient espClient;

PubSubClient client(espClient);

void setup(){

pinMode(trigPin,OUTPUT);
pinMode(echoPin,INPUT);

Serial.begin(9600);
delay(10);
Serial.println();
Serial.println();
Serial.print("connecting to");
Serial.print("ssid");
WiFi.begin("ssid","Password");
while (WiFi.status() !=WL_CONNECTED){
delay(500);
Serial.print(".");
}

Serial.println("");
Serial.println("WiFi connected");
Serial.println("IP address");
Serial.println(WiFi.localIP());
delay(3000);

client.setServer("Mqtt broker",1883);
client.setCallback(callback);

reconnect();

}

void callback(char* topic, byte* payload, unsigned int length)
{
String str;
Serial.print("Message Arrived [i]");
Serial.print(topic);
Serial.println(".");
for(int i=0; i<length; i++)
{
str+=((char)payload[i]);
}
Serial.println(str);
}
void reconnect()
{
while(WiFi.status()!=WL_CONNECTED)
{
delay(50);
Serial.print(".");
}
while(!client.connected())
{
if(client.connect("test"))
{
Serial.println("Connected...");
client.subscribe("test");
}
else
{
Serial.print("failed, rc=");
Serial.println(client.state());
delay(100);
}
}
}
void loop(){

    digitalWrite(trigPin, LOW);
    delayMicroseconds(2);
    
    digitalWrite(trigPin, HIGH);
    delayMicroseconds(10);
    digitalWrite(trigPin, LOW);

duration= pulseIn(echoPin,HIGH);

distance=duration*0.034/2;

Serial.print("distance= ");
Serial.println("distance");

if(distance<=10){

Serial.print("parking is not available");
client.publish("test","!!Parking is not available");
delay(2000);

}
else{
Serial.println("PARKING AVAIALBLE");
client.publish("test","PARKING AVAILABLE");
delay(2000);
}

if(!client.connected()){
reconnect();
}
client.loop();
client.subscribe("test");
}


And my output is coming like this .........................

[J-M-L]

Hello, do yourself a favour and please read How to get the best out of this forum and modify your post accordingly (including code tags and necessary documentation of your ask).

[hammy]

When you’ve done the above, after formatting , you’ll see you have procedures with the same name .
If you format the code ( tools/format) and tidy it up so all your functions are in one place and not scattered between setup and loop, it will be easier to read and errors more obvious.

Have a look at how functions work , you have defined at least one function twice , you don’t call them with “void....”

Link

[dave-in-nj]

Change what you print.
Serial.print("*")
("+")
("'")
("#")
So you know where it hangs

[vamshi9189]

It is hanging at connecting to WiFi part