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--- iothings:laboratoare:2025:lab3 [2025/10/11 12:36]
dan.tudose [Subscribe & control the on-board NeoPixel]
+++ iothings:laboratoare:2025:lab3 [2025/10/13 17:20] (current)
dan.tudose [Platformio.ini]
@@ Line 48: / Line 48: @@
     * ''sensors/room1''
     * ''sensors/temperature/office/room1''
+{{ :iothings:laboratoare:2025:single-level-wild-card--1-.png?600 |}}
 == # (Multi-Level Wildcard) ==
@@ Line 61: / Line 62: @@
   * ''#'' alone matches **all topics**.
+{{ :iothings:laboratoare:2025:single-level-wild-card--1--1.png?600 |}}
 == Rules and Constraints ==
@@ Line 112: / Line 115: @@
   adafruit/Adafruit BME680 Library
   bblanchon/ArduinoJson @ ^7
 dpi/MQTT @ ^2.5.2
+  knolleary/PubSubClient @ ^2.8
 </code>
@@ Line 124: / Line 128: @@
 Once connected, the ESP32 enters a loop where it continuously maintains the MQTT session, reconnects if needed, and publishes a heartbeat message every five seconds containing its uptime in milliseconds. This heartbeat acts as a regular signal that the device is alive. The code’s use of non-blocking MQTT functions keeps the system responsive, while the combination of retained status messages and the Last Will feature ensures other clients always know the ESP32’s current state — whether it’s online, offline, or actively sending updates.
-[[iothings:laboratoare:2025:lab3_code1| Click here to get the code for this example.]]
+[[iothings:laboratoare:2025_code:lab3_1|Click here to get the code for this example.]]
 After building and uploading to your Sparrow node, test it out using [[https://dantudose.github.io/labs/lab3_1.html | this link]].
@@ Line 138: / Line 141: @@
 After setting the LED color, the device publishes an acknowledgment message to a separate MQTT topic, confirming the values it received and applied. This acknowledgment lets any remote controller or dashboard know that the LED update was successful. The whole process uses the non-blocking, event-driven design of the 256dpi library, meaning it can handle MQTT communication efficiently without freezing the microcontroller’s main loop. In essence, this sketch turns the ESP32 into a small, networked RGB controller that listens for MQTT commands and reports its actions back to the broker.
-[[iothings:laboratoare:2025:lab3_code2| Click here to get the code for this example.]]
+[[iothings:laboratoare:2025_code:lab3_2| Click here to get the code for this example.]]
 Test it out using [[https://dantudose.github.io/labs/lab3_2.html | this link]].
@@ Line 148: / Line 151: @@
 Every ten seconds, the ESP32 reads environmental data from the on-board BME680 sensor—including temperature, humidity, pressure, and gas resistance—and packages those readings into a JSON message. It then publishes this JSON payload to an MQTT topic dedicated to that device’s sensor data. Any other MQTT clients subscribed to that topic can instantly receive and process the latest environmental information, such as for logging, visualization, or automation. In short, this code makes the ESP32 function as a small, networked environmental node that continuously streams live sensor data to the MQTT ecosystem while maintaining reliable connection status reporting.
-<code C main.cpp>
+[[iothings:laboratoare:2025_code:lab3_3|Click here to get the code for this example.]]
-#include <Arduino.h>
-#include <WiFi.h>
-#include <Wire.h>
-#include <MQTT.h>
-#include <ArduinoJson.h>
-#include <Adafruit_BME680.h>
-//////////////// EDIT THESE ////////////////
-const char* WIFI_SSID     = "YOUR_SSID";
-const char* WIFI_PASSWORD = "YOUR_PASSWORD";
-const char* MQTT_HOST     = "test.mosquitto.org";   // or your lab broker
-const uint16_t MQTT_PORT  = 1883;
-const char* BASE_TOPIC    = "iot/studentname";        // change per student
-////////////////////////////////////////////
-// Sparrow I2C: SDA=21, SCL=22
-#define SDA_PIN 21
-#define SCL_PIN 22
-Adafruit_BME680 bme;  // I2C
-WiFiClient net;
-MQTTClient mqtt(1024);   // 1KB message buffer
-void ensureWiFi() {
-  if (WiFi.status() == WL_CONNECTED) return;
-  WiFi.mode(WIFI_STA);
-  WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
-  Serial.print("WiFi connecting");
-  while (WiFi.status() != WL_CONNECTED) {
-    delay(400);
-    Serial.print(".");
-  }
-  Serial.printf("\nIP: %s\n", WiFi.localIP().toString().c_str());
-}
-void ensureMQTT() {
-  if (mqtt.connected()) return;
-  // Optional Last Will so dashboards see offline state
-  String willTopic = String(BASE_TOPIC) + "/bme688/status";
-  mqtt.setWill(willTopic.c_str(), "offline", true, 1);
-  String cid = String("sparrow-c6-sense-") + String((uint32_t)ESP.getEfuseMac(), HEX);
-  Serial.println("MQTT connecting...");
-  while (!mqtt.connect(cid.c_str())) {
-    Serial.print(".");
-    delay(1000);
-  }
-  Serial.println("\nMQTT connected");
-  // Publish "online" status retained
-  mqtt.publish(willTopic, "online", true, 1);
-}
-unsigned long lastPub = 0;
-void setup() {
-  Serial.begin(115200);
-  delay(200);
-  Wire.begin(SDA_PIN, SCL_PIN);
-  // MQTT broker + transport
-  mqtt.begin(MQTT_HOST, MQTT_PORT, net);
-  if (!bme.begin(0x76)) {           // Sparrow uses 0x76
-    Serial.println("BME688 not found!");
-    for(;;) { delay(1000); }
-  }
-  // Reasonable oversampling; heater off for simplicity
-  bme.setTemperatureOversampling(BME680_OS_8X);
-  bme.setHumidityOversampling(BME680_OS_2X);
-  bme.setPressureOversampling(BME680_OS_4X);
-  bme.setIIRFilterSize(BME680_FILTER_SIZE_3);
-  bme.setGasHeater(0, 0);  // off
-}
-void loop() {
-  ensureWiFi();
-  ensureMQTT();
-  mqtt.loop();     // process incoming/keepalive
-  delay(10);
-  if (millis() - lastPub > 10000) {
-    lastPub = millis();
-    if (!bme.performReading()) {
-      Serial.println("BME read failed");
-      return;
-    }
-    // Build JSON (ArduinoJson v7 style, no deprecated StaticJsonDocument)
-    JsonDocument doc;
-    doc["ts"]        = (uint32_t)(millis() / 1000);
-    doc["temp_c"]    = bme.temperature;
-    doc["hum_pct"]   = bme.humidity;
-    doc["press_hpa"] = bme.pressure / 100.0;
-    doc["gas_ohm"]   = bme.gas_resistance;
-    String payload;
-    serializeJson(doc, payload);
-    String topic = String(BASE_TOPIC) + "/bme688";
-    bool ok = mqtt.publish(topic, payload);  // QoS0, non-retained
-    Serial.printf("Pub %s => %s (%s)\n",
-                  topic.c_str(), payload.c_str(), ok ? "OK" : "FAIL");
-  }
-}
-</code>
 Test it out using [[https://dantudose.github.io/labs/lab3_3.html | this link]].
@@ Line 271: / Line 163: @@
 At the same time, the ESP32 regularly publishes telemetry data through MQTT. It sends heartbeat messages with uptime, signal strength, and network information, and it transmits environmental sensor readings from the BME680 to a designated topic as JSON data. All MQTT communication uses Quality of Service level 1 to ensure that messages are delivered at least once, providing reliable data exchange between the device and the broker. The code also manages automatic reconnection with exponential backoff, meaning it gracefully retries connecting to the MQTT broker when disconnected without flooding the network. In essence, from the MQTT point of view, this device behaves as a resilient, bidirectional IoT client that reports data, accepts remote commands, and maintains a persistent, reliable session with the broker.
-<code C main.cpp>
+[[iothings:laboratoare:2025_code:lab3_4|Click here to access your code for this example.]]
-#include <Arduino.h>
-#include <WiFi.h>
-#include <WiFiClientSecure.h>
-#include <MQTT.h>
-#include <Wire.h>
-#include <Adafruit_BME680.h>
-#include <Adafruit_NeoPixel.h>
-#include <ArduinoJson.h>
-//////////////// EDIT THESE ////////////////
-const char* WIFI_SSID     = "YOUR_SSID";
-const char* WIFI_PASSWORD = "YOUR_PASSWORD";
-const char* MQTT_HOST     = "test.mosquitto.org";   // or your lab broker
-const uint16_t MQTT_PORT  = 1883;
-const char* BASE_TOPIC    = "iot/studentname";         // change per student
-////////////////////////////////////////////
-#define SDA_PIN 21
-#define SCL_PIN 22
-#define NEOPIXEL_PIN 3
-WiFiClient net;
-MQTTClient mqtt(2048);
-Adafruit_BME680 bme;
-Adafruit_NeoPixel pixel(1, NEOPIXEL_PIN, NEO_GRB + NEO_KHZ800);
-unsigned long nextConnTry = 0;
-uint32_t backoffMs = 1000;
-unsigned long lastHeartbeat = 0;
-unsigned long lastSensorPub = 0;
-void ensureWiFi() {
-  if (WiFi.status() == WL_CONNECTED) return;
-  WiFi.mode(WIFI_STA);
-  WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
-  Serial.print("WiFi connecting");
-  while (WiFi.status() != WL_CONNECTED) { delay(500); Serial.print("."); }
-  Serial.printf("\nWiFi OK, IP: %s, RSSI: %d dBm\n", WiFi.localIP().toString().c_str(), WiFi.RSSI());
-}
-void setLED(uint8_t r, uint8_t g, uint8_t b, uint8_t brightness) {
-  pixel.setBrightness(brightness);
-  pixel.setPixelColor(0, pixel.Color(r, g, b));
-  pixel.show();
-}
-void handleLEDJson(const String& payload) {
-  JsonDocument doc;
-  DeserializationError err = deserializeJson(doc, payload);
-  if (err) { Serial.printf("LED JSON parse error: %s\n", err.c_str()); return; }
-  uint8_t r = doc["r"].isNull() ? 0 : doc["r"].as<uint8_t>();
-  uint8_t g = doc["g"].isNull() ? 0 : doc["g"].as<uint8_t>();
-  uint8_t b = doc["b"].isNull() ? 0 : doc["b"].as<uint8_t>();
-  uint8_t br = doc["brightness"].isNull() ? 100 : doc["brightness"].as<uint8_t>();
-  setLED(r,g,b,br);
-  JsonDocument ack;
-  ack["ok"] = true; ack["r"] = r; ack["g"] = g; ack["b"] = b; ack["brightness"] = br;
-  String out; serializeJson(ack, out);
-  mqtt.publish((String(BASE_TOPIC)+"/led/ack").c_str(), out.c_str(), false, 1);
-}
-void messageReceived(String &topic, String &payload) {
-  Serial.printf("MSG [%s]: %s\n", topic.c_str(), payload.c_str());
-  if (topic == String(BASE_TOPIC) + "/led") handleLEDJson(payload);
-}
-bool connectMQTT() {
-  String cid = String("sparrow-c6-qos1-") + String((uint32_t)ESP.getEfuseMac(), HEX);
-  mqtt.setCleanSession(true);
-  mqtt.setKeepAlive(30);
-  String willTopic = String(BASE_TOPIC) + "/status";
-  mqtt.setWill(willTopic.c_str(), "{\"status\":\"offline\"}", true, 1);
-  Serial.printf("MQTT connecting to %s:%u as %s ...\n", MQTT_HOST, MQTT_PORT, cid.c_str());
-  bool ok = mqtt.connect(cid.c_str(), nullptr, nullptr);
-  if (!ok) { Serial.printf("MQTT connect failed, error=%d\n", mqtt.lastError()); return false; }
-  mqtt.subscribe((String(BASE_TOPIC)+"/led").c_str(), 1);
-  mqtt.publish(willTopic.c_str(), "{\"status\":\"online\"}", true, 1);
-  Serial.println("MQTT connected");
-  return true;
-}
-void ensureMQTT() {
-  if (mqtt.connected()) return;
-  if (millis() < nextConnTry) return;
-  if (!connectMQTT()) {
-    backoffMs = min<uint32_t>(backoffMs * 2, 30000);
-    nextConnTry = millis() + backoffMs;
-    Serial.printf("Retry in %lu ms\n", (unsigned long)backoffMs);
-  } else {
-    backoffMs = 1000;
-  }
-}
-bool readBME(float& tC, float& hPct, float& pHpa, float& gas) {
-  if (!bme.performReading()) return false;
-  tC = bme.temperature;
-  hPct = bme.humidity;
-  pHpa = bme.pressure / 100.0;
-  gas = bme.gas_resistance;
-  return true;
-}
-void setup() {
-  Serial.begin(115200);
-  pixel.begin();
-  setLED(0,0,0,10);
-  Wire.begin(SDA_PIN, SCL_PIN);
-  if (!bme.begin(0x76)) {
-    Serial.println("BME688/BME680 not found at 0x76!");
-  } else {
-    bme.setTemperatureOversampling(BME680_OS_8X);
-    bme.setHumidityOversampling(BME680_OS_2X);
-    bme.setPressureOversampling(BME680_OS_4X);
-    bme.setIIRFilterSize(BME680_FILTER_SIZE_3);
-    bme.setGasHeater(0, 0);
-  }
-  mqtt.begin(MQTT_HOST, MQTT_PORT, net);
-  mqtt.onMessage(messageReceived);
-}
-void loop() {
-  ensureWiFi();
-  ensureMQTT();
-  mqtt.loop();
-  if (mqtt.connected() && millis() - lastHeartbeat > 15000) {
-    lastHeartbeat = millis();
-    JsonDocument hb;
-    hb["uptime_s"] = (uint32_t)(millis()/1000);
-    hb["ip"] = WiFi.localIP().toString();
-    hb["rssi"] = WiFi.RSSI();
-    String out; serializeJson(hb, out);
-    mqtt.publish((String(BASE_TOPIC)+"/heartbeat").c_str(), out.c_str(), true, 1);
-    Serial.printf("Heartbeat -> %s\n", out.c_str());
-  }
-  if (mqtt.connected() && millis() - lastSensorPub > 10000) {
-    lastSensorPub = millis();
-    float tC, hPct, pHpa, gas;
-    if (readBME(tC, hPct, pHpa, gas)) {
-      JsonDocument s;
-      s["ts"] = (uint32_t)(millis()/1000);
-      s["temp_c"] = tC;
-      s["hum_pct"] = hPct;
-      s["press_hpa"] = pHpa;
-      s["gas_ohm"] = gas;
-      String out; serializeJson(s, out);
-      mqtt.publish((String(BASE_TOPIC)+"/bme688").c_str(), out.c_str(), false, 1);
-      Serial.printf("Sensor -> %s\n", out.c_str());
-    } else {
-      Serial.println("BME read failed");
-    }
-  }
-}
-</code>
 Test it out using [[https://dantudose.github.io/labs/lab3_4.html | this link]].