Vehicle Health Monitoring with MQTT

System Overview

Prevent breakdowns and reduce maintenance costs by monitoring vehicle health in real-time. MQTT provides lightweight, reliable messaging for vehicle data.

Sensor Integration

Parameter	Sensor	Normal Range	Alert Threshold
Engine Temp	DS18B20/Thermocouple	85-95°C	>105°C
Oil Pressure	5V Pressure Sensor	25-65 PSI	<20 PSI
Battery Voltage	Voltage Divider	12.5-14.5V	<11.5V
Coolant Level	Float Sensor	MIN-MAX

Hardware Setup

• ESP32: Main controller
• ADS1115: 16-bit ADC for analog sensors
• MAX31855: Thermocouple amplifier
• INA219: Current/voltage monitor
• CAN Bus Module: Vehicle data

MQTT Architecture

# ESP32 MQTT Publisher
#include 

WiFiClient espClient;
PubSubClient client(espClient);

void publishHealthData() {
  StaticJsonDocument<512> doc;
  
  doc["vehicle_id"] = "VH001";
  doc["engine_temp"] = readEngineTemp();
  doc["oil_pressure"] = readOilPressure();
  doc["battery_voltage"] = readBattery();
  doc["timestamp"] = millis();
  
  char buffer[512];
  serializeJson(doc, buffer);
  
  client.publish("vehicle/health/VH001", buffer);
}

void connectMQTT() {
  client.setServer("mqtt.broker.com", 1883);
  while (!client.connected()) {
    client.connect("VehicleHealth_VH001");
  }
}

Alert System

# Node-RED Alert Flow
[
  {
    "id": "health-subscriber",
    "type": "mqtt in",
    "topic": "vehicle/health/+",
    "broker": "mqtt-broker"
  },
  {
    "id": "threshold-check",
    "type": "function",
    "func": "if (msg.payload.engine_temp > 105) {\n  msg.alert = {type: 'CRITICAL', message: 'Engine Overheating!'};\n} else if (msg.payload.oil_pressure < 20) {\n  msg.alert = {type: 'WARNING', message: 'Low Oil Pressure';\n}\nreturn msg;"
  },
  {
    "id": "notification",
    "type": "sendgrid",
    "api": "SENDGRID_API_KEY"
  }
]

Predictive Maintenance

Machine learning for failure prediction:

• Battery: Voltage trend analysis
• Engine: Temperature pattern recognition
• Brakes: Wear rate calculation
• Tires: Pressure loss trends