Arduino PLC: industrial controllers with original Arduino boards
Two families of DIN-rail PLCs with an original Arduino inside: M-Duino with Ethernet and up to 58 I/O, and the compact Ardbox with up to 20 I/O. Same Arduino IDE, same libraries, no licence fees and no vendor lock-in.
- M-Duino: Arduino Mega, Ethernet, RS-485 and RS-232, up to 58 I/O.
- Ardbox: Arduino Leonardo, RS-485 and RS-232, up to 20 I/O.
- Ardbox Q: Arduino UNO Q, real-time control plus Linux.
Why an Arduino PLC
The code your team already writes, on hardware made for an electrical panel.
Open hardware, industrial format
Save money: no software licences and no paid add-ons to scale from one machine to a series.
Work faster: the Arduino IDE and its libraries, so you prototype, test and deploy with the same code.
Stay in control: the schematics and pin maps are documented, so the controller works your way.
- Original Arduino insideMega in M-Duino, Leonardo in Ardbox, UNO Q in Ardbox Q.
- Up to 58 I/ODigital, analog and relay, depending on the model.
- RS-485 and RS-232Modbus RTU and serial devices on every model.
- Ethernet on M-DuinoModbus TCP, MQTT and a web server on the controller.
- Arduino IDE or PlatformIOWith the Industrial Shields boards package.
- 12 to 24 VdcIndustrial supply, DIN-rail enclosure.
Choose your family
Pick by the number of signals and whether you need Ethernet or Linux.
Arduino Mega · Ethernet
M-Duino
Up to 58 I/O with Ethernet, RS-485 and RS-232. For machines, lines and panels that talk Modbus TCP.
Arduino Leonardo · compact
Ardbox
Up to 20 I/O with RS-485 and RS-232 in a compact enclosure. For small machines and panels.
Arduino UNO Q · Linux
Ardbox Q
Real-time control on an STM32 plus Linux with Wi-Fi 5 and Bluetooth 5.1, for data and AI at the edge.
M-Duino vs Ardbox: which one fits your project?
Both run on the Arduino IDE. The relay models switch loads directly, without an external relay module.
| Model | Inputs | Outputs | Ethernet |
|---|---|---|---|
| Ardbox Analog | 10 | 10 | No |
| Ardbox Relay | 10 | 10 (8 relays) | No |
| M-Duino 19R | 6 | 11 (8 relays) | Yes |
| M-Duino 21 | 13 | 8 | Yes |
| M-Duino 38AR | 19 | 19 (8 relays) | Yes |
| M-Duino 38R | 12 | 22 (16 relays) | Yes |
| M-Duino 42 | 26 | 16 | Yes |
| M-Duino 57R | 18 | 31 (23 relays) | Yes |
| M-Duino 58 | 36 | 22 | Yes |
Every model has RS-485 and RS-232. Compare every model in detail.
What you can build with it
Real projects with the problem, the solution and the hardware they use.
M-Duino
Robotic welding cell
The robots weld one side while the operator loads the other.
Ardbox
Quality checks on a line
Three checks against bad parts with one small Ardbox PLC.
Learn and start
- Free course
Getting started with an Arduino-based PLC, step by step.
Start the course - M-Duino or Ardbox?
How to choose for an industrial retrofit.
Read the guide - Modbus RTU
Wiring and code on Arduino and ESP32 PLCs.
Modbus RTU guide - FAQ
Power supply, communications and choosing a model.
Read the FAQ
Questions about Arduino PLCs
Which Arduino is inside each family?
An original Arduino Mega in M-Duino, an Arduino Leonardo in Ardbox and an Arduino UNO Q in Ardbox Q.
How are they programmed?
With the Arduino IDE or PlatformIO and the Industrial Shields boards package. Ardbox Q also runs Python, Node-RED and Docker on its Linux side.
Which one has Ethernet?
Every M-Duino. Ardbox and Ardbox Q have no Ethernet; Ardbox Q has Wi-Fi on its Linux side.
What supply voltage do they need?
12 to 24 Vdc.
Talk to an engineer
Tell us what the system must do and which signals it has. An Industrial Shields engineer will answer with the right Arduino PLC and the next steps.