#include <WiFi.h>
#include <PubSubClient.h>
const int TRIG_PIN = 5; // Pin del trigger
const int ECHO_PIN = 18; // Pin del echo
const char* ssid = "Wokwi-GUEST";
const char* password = "";
const char* mqtt_server = "test.mosquitto.org";
WiFiClient espClient;
PubSubClient client(espClient);
unsigned long lastMsg = 0;
#define MSG_BUFFER_SIZE (50)
float distance = 0;
void setup_wifi() {
delay(10);
Serial.println();
Serial.print("Connecting to ");
Serial.println(ssid);
WiFi.mode(WIFI_STA);
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
randomSeed(micros());
Serial.println("");
Serial.println("WiFi connected");
Serial.println("IP address: ");
Serial.println(WiFi.localIP());
}
void callback(char* topic, byte* payload, unsigned int length) {
Serial.print("Message arrived [");
Serial.print(topic);
Serial.print("] ");
for (int i = 0; i < length; i++) {
Serial.print((char)payload[i]);
}
Serial.println();
}
void reconnect() {
while (!client.connected()) {
Serial.print("Attempting MQTT connection...");
String clientId = "ESP8266Client-";
clientId += String(random(0xffff), HEX);
if (client.connect(clientId.c_str())) {
Serial.println("Connected");
client.publish("/indobot/mqtt", "Indobot");
client.subscribe("/indobot/mqtt");
} else {
Serial.print("failed, rc=");
Serial.print(client.state());
Serial.println(" try again in 5 seconds");
delay(5000);
}
}
}
void setup() {
Serial.begin(115200);
setup_wifi();
client.setServer(mqtt_server, 1883);
client.setCallback(callback);
pinMode(TRIG_PIN, OUTPUT);
pinMode(ECHO_PIN, INPUT);
}
void loop() {
if (!client.connected()) {
reconnect();
}
client.loop();
unsigned long now = millis();
if (now - lastMsg > 2000) {
lastMsg = now;
// Send a 10us pulse to trigger the measurement
digitalWrite(TRIG_PIN, LOW);
delayMicroseconds(2);
digitalWrite(TRIG_PIN, HIGH);
delayMicroseconds(10);
digitalWrite(TRIG_PIN, LOW);
// Read the echo time
long duration = pulseIn(ECHO_PIN, HIGH);
// Calculate the distance in cm
distance = (duration / 2.0) * 0.0343;
String distanceStr = String(distance, 2);
Serial.print("Distance: ");
Serial.println(distanceStr);
client.publish("/indobot/distance", distanceStr.c_str());
}
}