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Ardbox PLC family: industrial control with Arduino Leonardo inside

The Ardbox brings Arduino Leonardo to the factory floor. 20 I/Os, galvanic isolation, RS-485 and Modbus — programmed entirely in Arduino IDE. A guide to both models.
June 10, 2026 by
Ardbox PLC family: industrial control with Arduino Leonardo inside
Joan F. Aubets - Industrial Shields

If you've ever built a working prototype with Arduino and then faced the challenge of deploying it in a real industrial environment — dealing with noise, 24 Vdc signals, relay loads, or Modbus networks — the Ardbox was built for exactly that moment.

The Ardbox is a compact industrial PLC that includes an original Arduino Leonardo board (ATmega32u4) as its controller. It runs entirely on Arduino IDE. And it's built to handle real industrial signals.

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Two models, one family

The Ardbox family comes in two distinct models, both sharing the same hardware platform and programming environment:

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Ardbox Analog: 20 I/Os for measurement and process control

The Ardbox Analog is the right choice when your application requires reading sensors, generating analog control signals, or mixing analog and digital I/O in a single device.

Inputs (10 total):

  • 2× Digital optoisolated inputs (5–24 Vdc)
  • 8× Analog/Digital 10-bit inputs (0–10 V or 5–24 Vdc, configurable by software)
  • 1× High-speed interrupt input (5–24 Vdc, galvanically isolated)

The 8 analog/digital inputs are particularly versatile: each one can be configured in software to work either as a 10-bit analog input (0–10 V) or as a digital optoisolated input (5–24 Vdc). The same hardware adapts to your wiring, not the other way around.

Outputs (10 total):

  • 3× Digital optoisolated outputs (5–24 Vdc, up to 70 mA each)
  • 7× Analog (0–10 Vdc) / Digital / PWM isolated outputs (5–24 Vdc)

Typical applications: temperature and pressure control loops, sensor data acquisition, analog signal generation for variable frequency drives, process monitoring.

Ardbox Relay: 18 I/Os for direct load switching

The Ardbox Relay shares the same input section as the Analog model but replaces the analog outputs with 8 relay outputs — ideal for switching real loads directly without external relay modules.

Inputs (10 total): same as Ardbox Analog: 2 digital + 8 configurable analog/digital + 1 interrupt.

Outputs (8 total):

  • 8× Relay outputs with galvanic isolation and diode protection
    • DC rating: 30 Vdc / 3 A
    • AC rating: 250 Vac / 5 A

These relay outputs handle real industrial loads: single-phase motors, solenoid valves, contactors, lamps, heaters. No external relay board needed.

Typical applications: motor starters, valve control, conveyor systems, HVAC control, door and gate automation.

The hardware: Arduino Leonardo at the core

Both models are based on an original Arduino Leonardo board — not a clone, not a compatible:

MicrocontrollerATmega32u4
Clock speed16 MHz
Flash memory32 KB (4 KB for bootloader)
SRAM2.5 KB
EEPROM1 KB
Power supply12–24 Vdc
Dimensions100 × 45 × 115 mm

The PLC runs on 12–24 Vdc, draws a maximum of 30 W, and operates between 0°C and 60°C — making it suitable for installation inside standard industrial control panels.

Communications and expandability

Serial communications: RS-485 (half/full), RS-232, SPI, I2C, USB

Protocols: Modbus RTU. Modbus TCP when using Ethernet-capable variants.

Expansion: Via I2C bus, up to 127 modules can be connected — enabling Master-Slave architectures with up to approximately 7,100 inputs and outputs.

Connectivity variants

The Ardbox hardware is available in five connectivity variants, all with the same I/O specs:

  • Standard — RS-485, RS-232, I2C, SPI (Ethernet option available)
  • WiFi & BLE — 2.4 GHz Wi-Fi + Bluetooth LE
  • GPRS/GSM — Cellular connectivity + Ethernet
  • LoRa — Long-range, low-power wireless (EU and USA frequency bands)
  • DALI — Digital Addressable Lighting Interface + Ethernet

Programming: Arduino IDE, as you'd expect

Because the Ardbox contains a genuine Arduino Leonardo board, programming is exactly what Arduino developers expect:

  1. Open a sketch in Arduino IDE
  2. Select the correct board (Arduino Leonardo)
  3. Use Industrial Shields libraries for simplified I/O access
  4. Upload via USB

Industrial Shields provides dedicated libraries for reading and writing Ardbox I/Os with clean, readable code. All libraries are open source and available on GitHub.

Beyond Arduino IDE, the Ardbox is also compatible with Node-RED, enabling visual programming for IIoT applications, dashboards, and server-side logic.

Certifications

  • CE, FCC, RoHS
  • EN61010-1 / EN61010-2-201
  • EN61131-2:2007 (Clause 8: Zone A/B EMC and clause 11: LVD)
  • EN61000-6-4:2007 + A1 2011 (Emissions)
  • EN61000-6-2:2005 (Immunity)
  • EMC: FCC Part 15

Which Ardbox is right for you?

Elige Ardbox Analog si tu aplicación implica lectura de sensores analógicos, generación de señal analógica de salida para variadores o actuadores, o E/S mixtas analógicas/digitales en un formato compacto.

Elige Ardbox Relay si tu aplicación implica conmutación directa de cargas AC o DC, control de motores, válvulas o actuadores sin módulos de relés externos, o aplicaciones que requieren contactos de relé con aislamiento galvánico.

Both models are available in all five connectivity variants.

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→ Buy Ardbox Analog · Buy Ardbox Relay · View technical specs

Download the Ardbox Family User Guide (PDF) or the full datasheet.

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Ardbox PLC family: industrial control with Arduino Leonardo inside
Joan F. Aubets - Industrial Shields June 10, 2026
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