What is an ESP32 PLC?
An ESP32 PLC is an industrial programmable controller built around an ESP32 or ESP32-S3 processor. It combines application logic with field-ready digital and analog I/O, outputs and DIN-rail installation.
ESP32 PLC Controllers
ESP32 PLC Controllers for Industrial Automation
NORVI ESP32 and ESP32-S3 PLC controllers combine industrial I/O, DIN-rail installation and built-in connectivity for machine control, monitoring and IIoT applications. Choose Wi-Fi, Ethernet, RS-485 or 4G models and program with Arduino IDE, ESP-IDF or MicroPython.
ESP32 / ESP32-S3 Industrial I/O Wi-Fi · Ethernet · 4G
6
Controller & gateway families
200
Max I/O Points (NORVI X)
3
Programming Environments
-10°C to +85°C
Operating Range
ESP32 PLC EXPLAINED
ESP32 PLC: Quick Answers
Three key questions to answer before choosing an industrial ESP32 controller.
ESP32 vs. a PLC: what is the difference?
A bare ESP32 is a microcontroller, while a PLC is a complete industrial controller. An ESP32-based PLC adds industrial interfaces and protective hardware, but it is not a substitute for a safety-rated PLC.
Which NORVI ESP32 PLC should I choose?
Choose NORVI IIOT for fixed I/O, ENET for wired Ethernet, GSM for cellular connectivity or NORVI X for modular expansion. Compare the controller lineup by I/O and networking needs.
Definition
What Is an ESP32 PLC?
A traditional PLC (programmable logic controller) reads field inputs like switches, sensors, and relays, runs a control program, and drives outputs to motors, valves, and indicators, all inside an industrial-rated enclosure. An ESP32 PLC does the same job. The difference is that the control program runs on an ESP32 or ESP32-S3 chip instead of a proprietary CPU.
NORVI builds its ESP32 PLC controllers around the ESP32-WROOM32 and ESP32-S3-WROOM modules. These are wired to optically isolated digital inputs, relay or transistor outputs, and 0 to 10V or 4 to 20mA analog channels, all behind screw-terminal blocks on a standard 35mm DIN rail. So you wire it like a PLC and program it like a development board, with Wi-Fi and Bluetooth built into every unit, plus Ethernet, RS-485 Modbus, or 4G LTE depending on the series you pick.
For a broader view of the available controller range, explore NORVI’s ESP32 industrial IoT controllers.
Why "ESP32-based PLC"
Same job, different core
- Digital, analog, relay and transistor I/O wired for 24V industrial field devices
- DIN-rail mounted, screw-terminal enclosures rated for panel installation
- Built-in wireless and/or wired networking on every controller, standard
- Programmed in Arduino IDE, ESP-IDF, or MicroPython, with no paid ladder-logic license required
- Modbus RTU/TCP support for integration into existing SCADA and HMI systems
Fit Assessment
When an ESP32 PLC Replaces a Traditional PLC
An ESP32 PLC will not fit every application, and that is fine. It is the right call when connectivity, cost, and development speed matter more to you than certified motion control or a vendor-backed safety rating.
Good fit
Choose an ESP32 PLC when you need
- Remote monitoring or SCADA data collection over Wi-Fi, Ethernet, or cellular
- Small-to-medium machine or process control: pumps, conveyors, HVAC, lighting
- Fast iteration using Arduino libraries instead of a locked engineering environment
- A lower per-unit hardware cost across an OEM product run
- Cloud-native data logging (MQTT, HTTP) without a separate IoT gateway
Keep a traditional PLC
Stay with Siemens / Allen-Bradley class hardware when you need
- Certified IEC 61131-3 ladder, SCL, or FBD logic with vendor safety approvals
- Integrated motion control, servo synchronization, or safety-rated I/O (SIL/PL)
- A large, standardized fleet already built on TIA Portal or Studio 5000
- Guaranteed deterministic scan times for high-speed motion applications
Product Lineup
Compare NORVI ESP32 PLC Controllers by I/O
Compare six NORVI controller and gateway families, from fixed-I/O panels to modular NORVI X, with expansion modules listed separately. Check model datasheets for exact channels and connectivity.
| Controller / accessory | Processor | I/O Highlights | Connectivity | Best For |
|---|---|---|---|---|
| NORVI IIOT | ESP32 dual-core @ 240MHz, 4MB Flash / 520KB SRAM | 6–8 Digital In (24V) · up to 8 Relay/Transistor Out · up to 6 Analog In (0–10V or 4–20mA) | 2.4GHz Wi-Fi + Bluetooth, RS-485 | Building automation, conveyor and pump control, mixed digital I/O panels |
| NORVI ENET | ESP32-WROOM32 dual-core, 4MB Flash / 520KB SRAM | 8 Digital In (18–32V) · 4 Relay (5A) / Transistor / 0–10V / 4–20mA Analog Out | W5500 wired Ethernet, Wi-Fi, Bluetooth | Wired plant networks, Modbus TCP/SCADA integration, data logging with RTC |
| NORVI GSM | ESP32-WROOM32 + SIM800C or Quectel EC25 | Digital In · Relay / 0–10V / 4–20mA Out · OLED display · microSD logging | 2G/4G cellular, Ethernet, Wi-Fi, Bluetooth | Remote sites with no local network, such as pumping stations, tanks, and unmanned assets |
| NORVI ESP32 HMI | ESP32-S3-WROOM dual-core | Digital In · Transistor Out · 0–10V / 4–20mA Analog · 5″ LCD touchscreen | Ethernet, RS-485, Wi-Fi, Bluetooth | Combined PLC + operator panel in one DIN-mount enclosure |
| NORVI X | ESP32-S3-WROOM-1U-N16R2 dual-core @ 160MHz, 16MB Flash / 520KB SRAM | Modular, scaling to 200 I/O points via 14+ hot-swap I²C expansion modules (digital, analog, relay, transistor, RTD) | Wi-Fi, Bluetooth 5.0, Ethernet RJ45, RS-485 Modbus, optional 2G/4G/high-speed 4G LTE | Machine builders and integrators standardizing on one scalable platform |
| Agent One | ESP32-WROVER32 | Digital In · 0–10V / 4–20mA Analog · Transistor Out · RGB status LED | LoRa, NB-IoT, Wi-Fi | Long-range sensor nodes and IoT gateways in the field |
| Expansion Modules | MCP23008 / MCP23017 / ADS1115 I²C peripherals | 16-bit Analog In (0–10V / 4–20mA) · Analog Out · Isolated Digital In · Transistor Out · 5A Relay Out | I²C to host controller | Scaling I/O on any NORVI IIOT, ENET, GSM, or X controller |
Full electrical ratings, dimensions, and per-model part numbers are listed on each product's datasheet. See the model tables below for links.
NORVI IIOT Series
NORVI IIOT: Fixed I/O with Wi-Fi and RS-485
Seven models built on a common ESP32 dual-core platform with a 0.96″ OLED display, RTC, and Arduino/ESP-IDF/MicroPython support. Operating range −40°C to +85°C, CE / RoHS / FCC certified.
NORVI-IIOT-AE01-R
8 DI · 6 Relay (5A) · 2 Transistor
Pump control panels, small–medium industrial automation with mixed relay/transistor loads.
NORVI-IIOT-AE01-T
8 DI · 8 Transistor Out
Low-power actuator control, alarms and indicator lamps with Modbus RS-485.
NORVI-IIOT-AE02-V
8 DI · 6 Analog In (0–10V) · 2 Transistor
HVAC and lighting control, pump/valve modulation, mixed analog-digital panels.
NORVI-IIOT-AE02-I
8 DI · 6 Analog In (4–20mA) · 2 Transistor
Water/wastewater and flow/level control using 4–20mA industrial sensors.
NORVI-IIOT-AE04-V
6 DI · 6 Analog In (0–10V) · 2 Transistor
Time-stamped data logging for small industrial processes and energy systems.
NORVI-IIOT-AE04-I
6 DI · 6 Analog In (4–20mA) · 2 Transistor
Chemical dosing and process control with time-stamped 4–20mA logging.
NORVI-IIOT-AE03
8 DI · 1 Analog In (0–10V)
Simple monitoring and single-analog-input applications for light industrial or lab use.
NORVI ENET Series
NORVI ENET: Wired Ethernet via W5500
ESP32-WROOM32 with a W5500 Ethernet controller, 0.96″ OLED, DS3231 RTC with battery backup, and microSD logging. Certified to EN 61131-2:2007, EN 61010-1:2010+A1:2019 and the EU EMC Directive 2014/30/EU.
NORVI-ENET-AE06-R · $128
8 DI · 4 Relay Out (5A)
Manufacturing process control and building management with wired Modbus TCP.
NORVI-ENET-AE06-T · $119
8 DI · 4 Transistor Out
Access control and low-power actuator switching over a wired plant LAN.
NORVI-ENET-AE06-V · $133
8 DI · 4 Analog In (0–10V)
Energy management and HVAC monitoring using 16-bit ADS1115 analog inputs.
NORVI-ENET-AE06-I · $147
8 DI · 4 Analog In (4–20mA)
Water treatment and industrial flow/pressure monitoring on current-loop sensors.
Full electrical specification: 8 isolated digital inputs (18–32V DC, 1kHz), 4 analog channels via ADS1115 16-bit ADC (0–10V, 38V DC withstand), IP20 enclosure, ESD protection 4kV contact / 8kV air. Full NORVI ENET specifications →
Modular Platform
NORVI X: The Scalable ESP32 PLC Board
One ESP32-S3 CPU module plus hot-swappable I²C expansion modules let you scale from a single relay output to 200 I/O points without rewiring the panel. It is IEC 61131-2 compliant, EN 61010-1 certified, and mounts on a standard DIN rail.
Wi-Fi 802.11 b/g/n
Bluetooth 5.0 BLE
Ethernet RJ45
RS-485 Modbus
Optional 2G/4G LTE
Standard
NORVI X1
Wi-Fi · Ethernet · Bluetooth 5.0
$79.00
- ESP32-S3-WROOM-1U-N16R2 dual-core
- Ethernet RJ45 + RS-485 Modbus built-in
- TFT SPI touchscreen, DS3231 RTC
- Scales to 200 I/O points
Most Popular
NORVI X2
Wi-Fi · Ethernet · 2G / 4G LTE
$95.00
- Adds SIMCOM A7672 2G/4G IoT modem
- Ethernet RJ45 + RS-485 built-in
- TFT touchscreen, DS3231 RTC
- Scales to 200 I/O points
High-Speed 4G
NORVI X3
Wi-Fi · Ethernet · High-speed 4G
$101.00
- Quectel EC25 high-speed 4G LTE modem
- Ethernet RJ45 + RS-485 built-in
- TFT touchscreen, DS3231 RTC
- Scales to 200 I/O points
14+ Hot-Swap Expansion Modules
| Module | Channels | Function | Price |
|---|---|---|---|
| NORVI X-DI4 | 4 | Fast optically isolated digital input for pulse counting and encoders | $29.00 |
| NORVI X-DI8 | 8 | Optically isolated digital input for switches and push-buttons | $30.97 |
| NORVI X-DI16 | 16 | High-density digital input for large-scale machine monitoring | $34.00 |
| NORVI X-R4 / X-R8 | 4 / 8 | Relay output for AC/DC loads, such as motor starters and contactors | R4 $28.00 / R8 $34.00 |
| NORVI X-Q4 / X-Q8 / X-Q16 | 4 / 8 / 16 | NPN transistor output for solenoids, steppers, and PLC-compatible loops | Q4 $23.00 / Q8 $31.00 / Q16 $46.00 |
| NORVI X-AV4 | 4 | 0–10V analog input for sensors and transducers | $28.00 |
| NORVI X-AI4 | 4 | 4–20mA current-loop input for pressure/flow/temperature transmitters | $33.00 |
| NORVI X-AQ4 | 4 | Dual-mode 0–10V / 4–20mA analog output for VFDs and proportional valves | $80.00 |
| NORVI X-RTD4 | 4 | Pt100/Pt1000 RTD input for precision temperature measurement | $38.00 |
| NORVI X-UART-IO | RS-485 ×2, RS-232 ×2, UART ×4 | Legacy serial device integration board | $29.00 |
Development
Programming Options for a NORVI ESP32 PLC
Every NORVI controller is programmed with open, free tooling instead of a licensed engineering suite. Choose the environment that matches your team's background.
Fastest to start
Arduino IDE
Read digital and analog GPIO with standard Arduino calls. NORVI publishes example sketches and a GitHub repository per controller so you can access every I/O channel without learning a new toolchain.
Full control
ESP-IDF
Espressif's native SDK for teams that need RTOS-level control, custom partitioning, or direct access to peripherals beyond what the Arduino core exposes.
Rapid scripting
MicroPython
Supported across the IIOT, ENET, and NORVI X series for teams that prefer Python-based scripting for prototyping and light logic.
A note on ladder logic: NORVI controllers do not run native IEC 61131-3 ladder logic. Every
model exposes Modbus RTU (RS-485) or Modbus TCP (Ethernet), though, so an existing ladder-based SCADA or HMI
system can read and write NORVI I/O as remote I/O. It is a common way to add wireless or budget I/O points to
a PLC architecture you already have.
Compliance
Certifications & Standards
Every NORVI controller is manufactured in-house with stage-by-stage compliance testing before it ships.
Electrical & Environmental
- EN 61131-2:2007, for programmable controller equipment requirements
- EN 61010-1:2010+A1:2019, for safety of electrical measurement equipment
- EN IEC 61010-2-201:2018, for safety requirements for control equipment
- 2014/30/EU EMC Directive, Annex III Part B Module C
- ESD protection: 4kV contact / 8kV air discharge
Product Marks
CE Certified
FCC Approved
IEC 61131-2
EN 61010-1
All NORVI controllers are manufactured at NORVI's own Sri Lanka facility, with full production traceability and compliance testing at every assembly stage. We do not outsource to third-party contract manufacturers.
PLC Alternatives
ESP32 PLC vs. Traditional PLC vs. ESP32 Board
Compare the three practical options by hardware, programming, industrial I/O, connectivity and safety requirements. The right choice depends on the exact control task and model.
| Factor | NORVI ESP32 PLC | Traditional PLC | Bare ESP32 board |
|---|---|---|---|
| Hardware | ESP32/ESP32-S3 controller built for industrial panel integration | Industrial CPU with vendor-specific I/O and enclosure options | Development or embedded microcontroller board |
| Field inputs & outputs | Model-dependent digital I/O, relays, transistors, 0–10 V and 4–20 mA | Industrial I/O modules and signal ranges depend on product family | Logic-level pins; industrial signal conditioning must be added |
| Programming | Arduino IDE, ESP-IDF or supported MicroPython firmware | Often IEC 61131-3 languages in a vendor development environment | Arduino IDE, ESP-IDF or MicroPython |
| Networking | Wi-Fi/Bluetooth; Ethernet, RS-485 or cellular on selected models | Industrial Ethernet/fieldbus varies; wireless often needs an accessory | Wi-Fi/Bluetooth on supported boards; industrial interfaces external |
| I/O expansion | Fixed-I/O NORVI series or modular NORVI X up to 200 I/O points | CPU and expansion-module limits depend on vendor model | Requires custom interface hardware and power design |
| Timing & safety | Check control-loop timing; not a safety-rated PLC | Model-specific deterministic features; dedicated safety PLC variants exist | Requires custom validation; no inherent industrial safety certification |
| Best fit | OEM automation, IIoT monitoring, connected machines and remote assets | Standardized plant controls, complex machine logic and safety applications | Prototyping, education and custom embedded devices |
Selection note: capabilities, certifications and response times depend on the specific device model and application design. Consult the relevant NORVI datasheet before specifying I/O or safety functions.
Use Cases
Where NORVI ESP32 PLCs Are Deployed
Building Automation
HVAC control, lighting management, and access control integration on Wi-Fi or wired Ethernet.
Manufacturing
Machine monitoring, production line control, and quality tracking with relay and transistor outputs.
Water & Wastewater
Pump control, level monitoring, and chemical dosing using 4–20mA analog inputs.
Learn MoreEnergy Management
Solar monitoring, load management, and power quality analysis via analog channels.
Agriculture
Greenhouse automation, irrigation control, and climate monitoring over Wi-Fi or LoRa.
Remote & Unmanned Sites
NORVI GSM and Agent One extend control to sites with no local network via cellular or LoRa.
No power at the site at all?
When You Need a Battery Logger Instead of a PLC
Every controller on this page still needs a 24V DC supply to run. If your site has no power source at all, such as a remote reservoir, an agricultural field, or an unmanned tank, an ESP32 PLC is not the right tool. The NORVI EC-M12 is a separate, purpose-built battery-powered data logger (not an ESP32 PLC) with a 38,000mAh battery pack rated for 5+ years of unattended service over NB-IoT, LTE-M, or LoRaWAN.
FAQs
Common Questions
Can't find what you're looking for? Our team is available for a free technical consultation.
What is an ESP32 PLC?
An ESP32 PLC is a programmable controller built around the ESP32 or ESP32-S3 system-on-chip, wired with industrial-grade digital inputs, relay or transistor outputs, and analog channels, so it can be wired and deployed like a traditional PLC while adding native Wi-Fi, Bluetooth, and often Ethernet or cellular connectivity.
Can an ESP32 actually replace a PLC?
For small-to-medium automation, remote monitoring, and IoT-connected control, yes. An ESP32 PLC handles digital and analog I/O, relay and transistor switching, and Modbus communication the same way a traditional PLC does. It is not a full replacement for applications that need certified motion control, safety-rated I/O, or vendor-guaranteed deterministic scan times.
Can I program a NORVI ESP32 PLC with ladder logic?
NORVI controllers are programmed in Arduino IDE, ESP-IDF, or MicroPython rather than native ladder logic. Because every model supports Modbus RTU or Modbus TCP, they can be read and written as remote I/O from an existing ladder-based SCADA or HMI system.
What is the I/O range of the NORVI ESP32 PLC lineup?
The fixed-I/O series (NORVI IIOT, ENET, GSM) ship with 6 to 8 digital inputs plus 2 to 8 relay, transistor, or analog channels. The modular NORVI X platform scales from a single expansion module up to 200 I/O points using hot-swappable I²C modules.
Is the ESP32 good enough for industrial automation?
Used inside a properly designed industrial enclosure, yes. On its own, a bare ESP32 dev board is not industrial-rated. NORVI's ESP32 PLC controllers add optically isolated I/O, DIN-rail housing, wide-temperature operation (down to -40°C on some series), and CE, RoHS, and EN 61131-2 testing on top of the chip to make it suitable for panel installation.
Which NORVI ESP32 PLC should a beginner start with?
The NORVI IIOT series is the simplest entry point: Wi-Fi and RS-485 built in, straightforward digital and analog I/O, and full Arduino IDE support with published example sketches. Move up to NORVI ENET or NORVI X once a project needs wired Ethernet, cellular connectivity, or I/O beyond what a fixed-I/O controller offers.
Resources
Downloads & Technical Resources
Documentation
Datasheets, user guides, and wiring references for every NORVI series.
View DocumentationReady to Spec Your ESP32 PLC?
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