ESP32 Modbus RTU Gateway Kit – Read Modbus RTU Data, Publish to MQTT Over WiFi

Every part needed, pre-tested for compatibility, with an AI build companion trained on this exact project. Shipped from Bengaluru in 3-5 days.

Industrial sensors speak Modbus RTU over RS485, but today’s dashboards and analytics run on MQTT. This kit puts you in control of that gap. You’ll assemble an ESP32 gateway that reads register values from any Modbus slave—temperature transmitter, energy meter, flow sensor—and streams them wirelessly to your MQTT broker. The 0.96-inch OLED gives instant feedback on the bench, making it perfect for B.Tech lab modules, CBSE IoT projects, or a fast industrial prototype you need to deploy by next week.

What You'll Build

A fully working RS485-to-MQTT gateway that polls Modbus RTU registers, displays selected values on the OLED, and publishes a JSON payload over WiFi. You can connect this to a real industrial sensor or test it with a Modbus simulator. Once running, you’ll see live data in Node-RED, Home Assistant, or any MQTT subscriber—exactly the kind of bridge used in factory digitization, building automation, and Smart India Hackathon prototypes.

What You'll Learn

• Read Modbus RTU registers over RS485 using a MAX485 transceiver and standard function codes
• Configure an ESP32 as an MQTT client, publishing sensor data to local or cloud brokers
• Drive a 0.96-inch I2C OLED display for real-time register inspection
• Power the entire system with a single 5V rail using the LM2596 buck converter

Kit Contents

Why Buy This Kit Instead of Sourcing Parts Separately

Who This Kit Is For

This kit is designed for CBSE Class 11–12 students crafting IoT coursework, B.Tech ECE / EEE learners tackling industrial communication lab experiments, and Smart India Hackathon teams building real-time monitoring proofs-of-concept. ATL Tinkering Lab mentors will find it a perfect hands-on introduction to Modbus, and engineering students at NIT, VIT, or BITS Pilani can use it as the backbone of a minor project or capstone submission.

Built and Backed by Compoden

Every Compoden kit ships with an AI build companion trained on this exact project — accessible via a QR code on the box, with WhatsApp and email backup. We've spent 10 years building projects for makers, schools, and institutions across India. If a part fails because of a manufacturing defect, replace it free within 7 days.