Arduino PLC

Type	Arduino-based industrial PLC
Core technology	Arduino Mega (M-Duino), Arduino Leonardo (Ardbox)
Operating system	None (bare metal)
Programming	Arduino IDE, C/C++
Native wireless	No
Linux support	No
Docker support	No
Node-RED support	No
Main role	Deterministic machine and process control
Certifications	CE, RoHS. ETL on M-Duino 21, 42, 58

What it is

An Arduino PLC is an industrial programmable logic controller based on Arduino architecture, designed for deterministic control of machines and processes through digital and analog inputs and outputs. Industrial Shields produces two Arduino PLC ranges: M-Duino (Arduino Mega, with Ethernet) and Ardbox (Arduino Leonardo, compact format).

When to use it

Machine control and process automation requiring deterministic execution
Applications where Arduino IDE and the Arduino ecosystem are preferred
Installations requiring ETL certification (North American market) — M-Duino 21, 42, 58
Projects with straightforward I/O requirements and no need for an operating system

When not to use it

When the project requires Linux, Python, Docker or Node-RED
When native wireless connectivity (WiFi, Bluetooth) is needed — use ESP32 PLC instead
When heavy local data processing or edge computing is required — use Raspberry Pi PLC instead
When CODESYS or IEC 61131-3 programming is required — use Raspberry Pi PLC instead

Key features

Deterministic bare-metal execution — no OS overhead
DIN rail format, 24V DC industrial power
Wide I/O range: 17–58 points (M-Duino), 20 points (Ardbox)
Ethernet standard on all M-Duino models
Industrial Shields open-source library: github.com/Industrial-Shields

Compatible software and protocols

Arduino IDE (C/C++)
Ethernet, RS485, RS232, Modbus RTU, Modbus TCP, MQTT, I2C, SPI, UART

M-Duino PLC range — I/O specifications

All M-Duino models include Ethernet. Analog/convertible inputs configurable as 0–10V or 4–20mA. All digital outputs support PWM.

Model	Analog in	Digital in	Digital out	Relay	Total I/O	Certifications	Price
M-Duino 19R	4	2	3	8	17	CE, RoHS	€219
M-Duino 21	6	7	8	0	21	CE, RoHS, ETL	€199
M-Duino 38AR	10	9	11	8	38	CE, RoHS	€279
M-Duino 38R	8	4	6	16	34	CE, RoHS	€299
M-Duino 42	12	14	16	0	42	CE, RoHS, ETL	€269
M-Duino 57R	12	6	8	23	49	CE, RoHS	€379
M-Duino 58	16	20	22	0	58	CE, RoHS, ETL	€339

Ardbox PLC range — I/O specifications

Model	Analog in	Digital in	Digital out	Relay	Total I/O	Price
Ardbox Analog	8	2	10	0	20	€129
Ardbox Relay	6	4	2	8	20	€139

Prices are reference prices and may change. Verify at the official product page before purchasing.

Typical applications

Machine control and process automation
HVAC control and monitoring
Conveyor belt and motor control
Automated car wash systems
Animal feeding automation