IoT Frontier: ESP32 Integration with DHT22 and Node-RED

Introduction

• Host: Hariharna
• Topic: Simulating ESP32 integration with DHT22 using WalkPay
• Objective: Send temperature and humidity to Node-RED dashboard via MQTT
• Reminder to like and subscribe

Previous Video

• Overview of sending temperature/humidity using ESP8266 with DHT11 sensor
• Link to previous video provided

Wokwi.com Overview

• Wokwi: Simulator tool for IoT projects without hardware
• Simulation Setup:
  • Select ESP32 board from Wokwi
  • Use starter template for setup
  • Adding components: DHT22 sensor
• Wiring connections:
  • VCC to 3V
  • SDA to GPIO 2
  • Ground to GND

Code Setup

Libraries Needed

• Wi-Fi library
• PubSub MQTT library
• DHT sensor library

Code Explanation

• Initialization of libraries and variables for temperature/humidity
• Connection to Wi-Fi using SSID and password
• MQTT broker connection: Broker URL - broker.hivemq.com
• Reconnection logic for MQTT
• Pin setup for DHT22 and built-in LED
• Reading temperature and humidity using DHT library

Publishing Data

• Data published to topics:
  • IoT Frontier/temperature
  • IoT Frontier/humidity

GitHub and Simulation

• Code available on GitHub for reference
• Steps to compile and start simulation on Wokwi

Node-RED Setup

Installation

• Launch Node-RED via PowerShell
• Configuration of MQTT nodes:
  • Set server and topic for subscription
  • Use QoS settings

Dashboard Configuration

• Installation of Node-RED dashboard library
• Adding gauge and chart nodes for temperature and humidity
• Deployment of the dashboard

Simulation Execution

• Start simulation in Wokwi to publish data
• Live monitoring of data in Node-RED debug window
• Dashboard view for real-time updates

Conclusion

• Recap of the entire simulation process
• Interactive demonstration of changing values on the dashboard

Closing Remarks

• Request for comments on future tutorials
• Reminder to like and subscribe
• Thank you for watching!