Ini
[env:esp32dev]
platform = espressif32
board = esp32dev
framework = arduino
monitor_speed = 115200
lib_deps =
  knolleary/PubSubClient
  emelianov/modbus-esp8266
  bblanchon/ArduinoJson

Cpp
#define PIN_RS485_RX      16
#define PIN_RS485_TX      17
#define PIN_RS485_DE_RE    4
#define PIN_HALL_RPM      27
#define PIN_BOOT           0

#define MODBUS_BAUD     9600
#define MQTT_PORT       8883

Cpp
#include <Arduino.h>
#include <WiFi.h>
#include <WiFiClientSecure.h>
#include <PubSubClient.h>
#include <ArduinoJson.h>

#define PIN_RS485_RX      16
#define PIN_RS485_TX      17
#define PIN_RS485_DE_RE    4
#define PIN_HALL_RPM      27
#define MODBUS_BAUD     9600

const char* WIFI_SSID = "YOUR_WIFI";
const char* WIFI_PASS = "YOUR_PASSWORD";
const char* AWS_ENDPOINT = "your-endpoint-ats.iot.us-east-1.amazonaws.com";
const char* MQTT_TOPIC = "turbine/telemetry";

WiFiClientSecure net;
PubSubClient mqtt(net);
HardwareSerial RS485(2);

volatile uint32_t hallPulses = 0;
uint32_t lastSampleMs = 0;
float rotorRpm = 0;

void IRAM_ATTR onHallPulse() {
  hallPulses++;
}

void rs485TransmitMode(bool enable) {
  digitalWrite(PIN_RS485_DE_RE, enable ? HIGH : LOW);
  delayMicroseconds(20);
}

void connectWiFi() {
  WiFi.mode(WIFI_STA);
  WiFi.begin(WIFI_SSID, WIFI_PASS);
  while (WiFi.status() != WL_CONNECTED) delay(500);
}

void connectMQTT() {
  net.setInsecure(); // Replace with AWS root CA + device certificate for production.
  mqtt.setServer(AWS_ENDPOINT, 8883);
  while (!mqtt.connected()) {
    mqtt.connect("esp32-wind-turbine-monitor");
    delay(500);
  }
}

float readModbusPlaceholder(uint8_t slaveId, uint16_t reg) {
  // TODO: replace with real Modbus RTU request/CRC/register parsing for each sensor.
  (void)slaveId;
  (void)reg;
  return 0.0f;
}

void publishTelemetry() {
  StaticJsonDocument<384> doc;
  doc["wind_speed"] = readModbusPlaceholder(1, 0x0000);
  doc["wind_direction"] = readModbusPlaceholder(2, 0x0000);
  doc["dc_voltage"] = readModbusPlaceholder(3, 0x0000);
  doc["dc_current"] = readModbusPlaceholder(3, 0x0001);
  doc["dc_power"] = readModbusPlaceholder(3, 0x0002);
  doc["energy_kwh"] = readModbusPlaceholder(3, 0x0003);
  doc["rotor_rpm"] = rotorRpm;

  char payload[384];
  serializeJson(doc, payload);
  mqtt.publish(MQTT_TOPIC, payload);
}

void setup() {
  pinMode(PIN_RS485_DE_RE, OUTPUT);
  rs485TransmitMode(false);
  pinMode(PIN_HALL_RPM, INPUT_PULLUP);
  attachInterrupt(digitalPinToInterrupt(PIN_HALL_RPM), onHallPulse, FALLING);

  Serial.begin(115200);
  RS485.begin(MODBUS_BAUD, SERIAL_8N1, PIN_RS485_RX, PIN_RS485_TX);

  connectWiFi();
  connectMQTT();
}

void loop() {
  if (!mqtt.connected()) connectMQTT();
  mqtt.loop();

  uint32_t now = millis();
  if (now - lastSampleMs >= 1000) {
    noInterrupts();
    uint32_t pulses = hallPulses;
    hallPulses = 0;
    interrupts();

    // Assumes 1 pulse/revolution; change if the rotor magnet count differs.
    rotorRpm = pulses * 60.0f;
    publishTelemetry();
    lastSampleMs = now;
  }
}

1. Program over USB-C / CP2102N at 115200 baud.
2. Verify 3.3 V rail before inserting/programming firmware.
3. Confirm RS485 sensor slave IDs and register maps for the exact wind and JSY-MK-229 devices.
4. Replace net.setInsecure() with AWS IoT root CA, device certificate, and private key before deployment.