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EDWartens UK

Free course · IIoT

ESP32 Industrial IoT: Sensors to MQTT Dashboards

Build a field-ready ESP32 monitoring node the way an industrial job needs it: the ESP32 family and the Arduino-ESP32 3.x core, GPIO, 24 V inputs, relays and PWM, the ADC and external converters, 4-20 mA and 0-10 V signals with NAMUR NE 43 checks, Modbus RTU over RS-485 and Modbus TCP, MQTT with JSON, last will and TLS, watchdogs, FreeRTOS tasks and store-and-forward, OTA and deep sleep, 24 V power, surge and EMC protection, Node-RED, InfluxDB and Grafana dashboards, and a tank level monitor capstone.

See the modules

Free to learn. Verifiable certificate £19 when you pass the final exam (optional, VAT included).

Level
Beginner
Modules
13
Video
21 hours
Price
Free

Outcome

What you will be able to do

Choose an ESP32 board for a field job and plan its pins around flash, strapping, input-only and ADC2 restrictions; write non-blocking Arduino-ESP32 3.x firmware for 24 V inputs, interrupts, relays and LEDC PWM; read calibrated millivolts and add an ADS1115 where accuracy demands it; condition and scale 4-20 mA and 0-10 V signals and report NE 43 faults; poll meters over Modbus RTU and serve or read Modbus TCP over Wi-Fi or Ethernet; publish JSON over MQTT with a retained last will, safe reconnects and TLS; keep a node alive with watchdogs, tasks, NVS settings and store-and-forward; update it over the air and run it from a battery; power and protect it in a 24 V panel; build dashboards with alarms that operators trust; and commission and document a tank level monitor.

  • Plan ESP32 pins for a field node around flash, strapping, input-only and ADC2 rules
  • Read 24 V contacts through optocouplers, count pulses with interrupts and drive relays and LEDC PWM on the 3.x core
  • Read calibrated millivolts, scale 4-20 mA and 0-10 V signals and report NAMUR NE 43 faults
  • Wire RS-485 correctly and poll Modbus RTU meters, and build Modbus TCP frames over Wi-Fi or Ethernet
  • Publish JSON over MQTT with a retained last will, non-blocking reconnects and TLS
  • Keep a node alive with FreeRTOS tasks, the task watchdog, NVS settings and store-and-forward
  • Update firmware over the air, estimate battery life from deep sleep, and power and protect a node in a 24 V panel
  • Build Node-RED, InfluxDB and Grafana dashboards with trustworthy alarms, and commission a tank level monitor

Software

All free: Arduino IDE 2 with the Arduino-ESP32 core 3.x (boards manager URL https://espressif.github.io/arduino-esp32/package_esp32_index.json), the Wokwi online simulator, the PubSubClient, ArduinoJson and ModbusMaster libraries, Eclipse Mosquitto, MQTT Explorer, Node-RED with the FlowFuse Dashboard (Dashboard 2.0), InfluxDB and Grafana. ESP-IDF (Apache 2.0) is introduced for reference.

Hardware

Optional: every exercise runs in the Wokwi simulator. To build a real node: an ESP32 development board, a TTL to RS-485 module, a 120 ohm 0.1 percent shunt, a 4-20 mA transmitter or loop calibrator, a 24 V DC supply and a buck converter; an ESP32 Ethernet board (WT32-ETH01 or W5500) is useful but not required.

Syllabus

13 modules

Each module has video lessons, notes and a short quiz. The final exam closes the course.

  1. 1The ESP32 for industrial IoT: chips, boards, Arduino IDE and Wokwi4 lessons
  2. 2Digital I/O: GPIO, interrupts, 24 V inputs, relays and PWM4 lessons
  3. 3Analog inputs: the ESP32 ADC, calibration and external ADCs4 lessons
  4. 44-20 mA and 0-10 V signals: shunts, dividers, scaling and faults4 lessonsLab
  5. 5Modbus RTU over RS-485: wiring, frames and polling meters5 lessonsLab
  6. 6Networking the node: Wi-Fi, Ethernet and Modbus TCP4 lessonsLab
  7. 7MQTT from the ESP32: PubSubClient, JSON, last will and TLS6 lessonsLab
  8. 8Firmware that survives the field: watchdogs, tasks and store-and-forward4 lessons
  9. 9OTA updates and low power: ArduinoOTA, HTTP update and deep sleep3 lessons
  10. 10E3210: Hardware for the panel: 24 V power, protection, EMC and enclosures6 lessons
  11. 11E3211: Dashboards: Mosquitto, Node-RED Dashboard 2.0, InfluxDB and Grafana5 lessons
  12. 12E3212: Capstone: an ESP32 tank level monitor from transmitter to dashboard3 lessonsLab
  13. 13E3213: Final assessment1 lesson

How it works

How this course works

  1. Watch the video lessonsOne module at a time, at your own pace.
  2. Take the module quizA short quiz at the end of each module shows what stuck.
  3. Keep your notesWrite in My notes beside each module and ask the trainer if you are stuck.
  4. Practise in the labOptionalTry a task from the module in the EDWartens Lab, in your browser.
  5. Sit the final examPass it once you have been through the modules.
  6. Certificate, if you want oneOptionalPaid, and only after you pass. Anyone can check it online.

EDWartens Lab

Practise this in the EDWartens Lab

Practise the field-side half of your sensor node: wire a 4 to 20 mA level transmitter, scale it and see why a broken loop must read as a fault.

Works alongside ESP32 Industrial IoT: Sensors to MQTT Dashboards. The Lab is control panel build practice in your browser: no install, no hardware, free to use. Sign in as a learner and it opens with your account.

Open the free lab See the Lab
Control panel build: Wire a real control panel.

Levels to try with this course

Optional. Skip it whenever you like: it never blocks your progress or your certificate.

Why practise in a lab

Technical work is judged on what you can do: wiring, commissioning, finding a fault. Doing a task yourself teaches more than watching it a second time, and a lab lets you try it safely before you meet real equipment. It does not replace working on real hardware.

  • Practise safely, so a mistake costs nothing.
  • The lab checks your work like a site test, so you know when it is right.
  • Free, in your browser, with nothing to install.

Certificate

An optional certificate when you pass

Learning is free. Pass the final exam and you can have a certificate for £19, including VAT, with a number employers can check online. It records that you completed a free online course; it is not a regulated qualification or a CPD certificate.

  • Your name, the course, its study time and your final exam score
  • A unique certificate number and a QR code to its verification page
  • Issued by Wartens Ltd; add it to your LinkedIn profile in one click
  • Pay now or after you pass: it is issued the moment you pass the final

How the certificate works

Sample certificate for ESP32 Industrial IoT: Sensors to MQTT Dashboards

Credits

Who made the lessons

The video lessons belong to their creators. EDWartens wrote the study plan, notes, quizzes and the final exam.

  • DIY TechRush

    getting started with an ESP32 board in the Arduino IDE, controlling relay boards, and connecting the ESP32 to Wi-Fi

  • Hardware.ai

    the ESP32 chip family explained in under 500 seconds

  • PrivAI Compute Labs

    which ESP32 to buy: the S2, S3, C3, C6 and H2 compared

  • Programming Electronics Academy

    the Wokwi ESP32 simulator, OTA updates with the ESP32, and getting started with deep sleep

  • Paul McWhorter

    pushbuttons with pull-up and pull-down resistors, pulse width modulation, and reading analog voltages (Arduino tutorials 27, 8 and 10)

  • Andreas Spiess

    ESP32 interrupts and deep sleep under the hood, how good the ESP32 ADC is against an ADS1115, RS-485 Modbus sensors on an ESP32, and working with FreeRTOS

  • G6EJD - David

    the ESP32 ADC's advanced functions and calibration

  • How To Electronics

    the ADS1115 16-bit ADC with the ESP32, and reading sensor data over Modbus RTU

  • Texas Instruments

    4-20 mA current loop transmitters, what RS-485 is, TVS diode specifications and the IEC 61000-4-5 surge standard

  • RealPars

    2-wire and 4-wire transmitter output loops

  • Werewolf Wu

    a 4-20 mA sensor explained with a simple microcontroller example

  • Impulse Tech

    connecting an industrial 4-20 mA sensor to an ESP32 for monitoring

  • ICP DAS USA, Inc.

    Modbus in two minutes, RTU against TCP (also the final recap)

  • Antony Cartwright (Electronics & Code)

    making Modbus work on an ESP32 over RS-485

  • DroneBot Workshop

    Ethernet and Power over Ethernet with the ESP32, ESP32 non-volatile storage, OTA updates, and the ESP32 Guide 2026 for choosing a board

  • Yaser Ali Husen

    uploading code to a WT32-ETH01 Ethernet board, and a Modbus TCP server with Node-RED as the client

  • IoT Bhai

    a beginner's guide to the ESP32 and MQTT

  • OhioIoT

    connecting and publishing with the PubSubClient library

  • High Voltages

    simulating an ESP32 MQTT project in Wokwi

  • HiveMQ

    setting up TLS for a cloud MQTT broker

  • IoT Frontier

    mutual TLS between an ESP32 and Node-RED, an ESP32 MQTT dashboard in Node-RED, a Node-RED, InfluxDB and Grafana dashboard, and the end-to-end capstone-style project

  • Kolban Technical Tutorials

    how the ESP32 watchdogs work

  • Simply Explained

    multitasking with FreeRTOS on the ESP32

  • KARTIS

    how to power microcontroller projects properly

  • Nexperia

    the basics of ESD and TVS protection

  • Hans Rosenberg

    the PCB grounding mistakes that cause noise problems

  • DonskyTech

    installing and testing the Mosquitto broker on Windows

  • Steve Cope

    an introduction to Node-RED Dashboard 2

  • Michael Klements

    a Grafana dashboard fed by an ESP32 through InfluxDB

  • Tech StudyCell

    an ESP32 water level monitoring system

  • Electronic Clinic

    water level monitoring with a waterproof ultrasonic sensor and an ESP32

Questions

About this course

What does this ESP32 industrial IoT course teach?
It teaches you to build an ESP32 node that reads real plant signals (24 V contacts, 4-20 mA transmitters and Modbus meters) and publishes them over MQTT to dashboards and history. Along the way it covers the Arduino-ESP32 3.x core, signal conditioning, Modbus RTU and TCP, MQTT with TLS, watchdogs, OTA updates, panel power and protection, and a tank level monitor capstone.
Who is this ESP32 IoT course for, and what do I need to know first?
It is for electrical, instrumentation and automation technicians and engineers, students and makers who want to build industrial monitoring nodes. You need basic electricity such as Ohm's law, volts and milliamps; programming is taught from the first sketch, so no coding experience is assumed.
Do I need an ESP32 board or other hardware?
No. Every exercise runs in the free Wokwi simulator, including Wi-Fi and MQTT. A real ESP32 board, an RS-485 module, a 120 ohm shunt and a loop calibrator make the hardware modules hands-on, and they are inexpensive, but they are optional.
What software does the course use, and is it free?
Yes, everything is free: Arduino IDE 2 with the Arduino-ESP32 3.x core, Wokwi, the PubSubClient, ArduinoJson and ModbusMaster libraries, Eclipse Mosquitto, MQTT Explorer, Node-RED with Dashboard 2.0, InfluxDB and Grafana. All code in the notes is written for the current 3.x core.
Is the course free to learn, and how long does it take?
Yes, the lessons, notes, worked problems, practice tasks, project and final assessment are free to learn. It takes about 21 hours at your own pace, including about 13.3 hours of video; the optional project adds about 16 hours.
What certificate do I get, and how is it verified?
You get a verifiable certificate of completion from EDWartens when you finish every module and pass the 15-question final at 60 percent. It has a unique certificate number and a QR code that open a public verification page showing the course, the modules covered and your final score. It is not an Espressif, Arduino or Modbus Organization credential.
Which standards and protocols does the course follow?
It follows the Modbus RTU and TCP specifications, MQTT (ISO/IEC 20922), TIA/EIA-485 for RS-485, NAMUR NE 43 for 4-20 mA fault currents, the IEC 61000-4 and IEC 61000-6 series for surge and EMC, and IEC 60529 for IP ratings, all explained in our own words. These are the same rules that water utilities, solar plants and factories apply from the Gulf to Africa and Asia.
How is this different from the Industrial DataOps, Node-RED and OpenPLC courses?
This course builds the device: the sensor wiring, firmware and protection that turn field signals into reliable MQTT data. Industrial DataOps covers what happens at plant scale (OPC UA, Sparkplug B, Unified Namespace), Node-RED for Industrial IoT goes deep into Node-RED, and OpenPLC teaches control in IEC 61131-3 on the same hardware.

The Professional Module is five live days of Siemens PLC, HMI and SCADA with an instructor, then a resume session and a CPD certificate.

See the Professional Module