#include <WiFi.h>
#include <PubSubClient.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
// Constants
const char *ssid = "Wokwi-GUEST";
const char *password = "";
const char *mqtt_server = "broker.emqx.io";
const char *mqtt_username = "";
const char *mqtt_password = "";
const char *mqtt_topic = "parsing";
// OLED Setup
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);
// Function prototypes
void setupWiFi();
void setupMQTT();
void callback(char *topic, byte *payload, unsigned int length);
void displayPoints(int points);
WiFiClient espClient;
PubSubClient client(espClient);
void setup() {
Serial.begin(115200);
// Setup OLED
if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
Serial.println(F("SSD1306 allocation failed"));
for(;;);
}
display.display();
delay(2000);
display.clearDisplay();
display.setTextColor(SSD1306_WHITE);
setupWiFi();
setupMQTT();
}
void loop() {
if (!client.connected()) {
setupMQTT();
}
client.loop();
}
void setupWiFi() {
delay(10);
Serial.println();
Serial.print("Connecting to WiFi");
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());
}
void setupMQTT() {
client.setServer(mqtt_server, 1883);
client.setCallback(callback);
while (!client.connected()) {
Serial.print("Attempting MQTT connection...");
if (client.connect("ESP32Client", mqtt_username, mqtt_password)) {
Serial.println("connected");
client.subscribe(mqtt_topic);
} else {
Serial.print("failed, rc=");
Serial.print(client.state());
Serial.println(" try again in 5 seconds");
delay(5000);
}
}
}
void callback(char *topic, byte *payload, unsigned int length) {
Serial.print("Message arrived [");
Serial.print(topic);
Serial.print("] ");
String message = "";
for (int i = 0; i < length; i++) {
message += (char)payload[i];
}
Serial.println(message);
// Parsing message
int separatorIndex = message.indexOf(',');
if (separatorIndex != -1) {
String trigger = message.substring(0, separatorIndex);
String pointsStr = message.substring(separatorIndex + 1);
if (trigger.equals("yes")) {
int points = pointsStr.toInt();
displayPoints(points);
}
}
}
void displayPoints(int points) {
display.clearDisplay();
display.setTextSize(3);
display.setCursor(0, 0);
display.print("Points: ");
display.print(points);
display.display();
}