The UniPi Neuron is a modular Programmable Logic Controller (PLC) product line, designed to be used as a central control unit for control, regulation and monitoring of smart building systems, HVAC (Heating, Ventilation, Air Conditioning) systems and industrial automation. Thanks to its modular architecture and compact design, the Neuron represents a highly flexible and affordable solution for quickly expanding field of smart technology. Customers can also utilize the Neuron for smart energy management to achieve better energy efficiency and reduce expenses.

The Neuron is suitable for:

  • smart home automation
  • construction companies
  • electrical installation
  • energy management
  • HVAC automation
  • remote control and SCADA (Supervisory Control And Data Aquisition)
  • companies providing BMS (Building management system) services
  • garden and agriculture automation
  • geeks and DYI enthusiasts
  • beverage industry
  • datacenters
  • industrial monitoring
  • small industry projects, and many more.

Neuron is designed to be suitable for nearly every automatization project.



Each Neuron model is divided into one to three input-output (I/O) groups depending on model, each containing a group of input, output and/or communication modules. Each I/O circuit board is controlled by its own STM32 processor, which controls inputs and outputs and communicates with the central processing unit (CPU). Processors are using our own firmware containing not only basic I/O functions, but also additional functions and features. I/O modules of each group are labeled to minimize the risk of mismatch.


As the CPU of all Neuron units, the Raspberry Pi single-board computer is used. Each I/O group processor is connected to the CPU and to a central communication channel for all group processors. There is no communication between I/O groups. Each processor can also function independently on the CPU, allowing users to retain basic control of I/O modules in the event of CPU malfunction or software issue. The whole system is assembled into a grounded eloxed aluminium case with an IP20 degree of protection.

The following picture shows inputs, outputs and group labeling on the Neuron L40x-series unit:

Group 1 Group 2 Group 3



Thanks to their modular design, I/O boards are fully interchangeable. Thanks to that, a new model can be created by simply swap existing I/O groups or changing them for entirely new one, adding more functionality. We created 12 modules differing in number and type of I/O's with each of them being based on the S103 model - the core model of the whole line.

Currently, we have 12 models of Neuron PLC unit, which can be equipped with

  • up to 64 digital inputs
  • up to 4 digital outputs
  • up to 56 relay outputs
  • up to 9 analog inputs
  • up to 9 analog outputs
  • up to 3 RS485 universal bus ports
  • various combinations of the above-mentioned

Communication interface

As standard, all Neuron units are equipped with the RS485-Modbus and the 1-Wire communication interfaces. The 1-Wire low-speed is used for passive data collection from various attached sensors such as thermometers, humidity meters and other measuring devices. The 1-Wire low-speed data bus allows up to 15 devices with unique HW addresses to be connected to each channel. Modbus is then a communication protocol using the RS485 serial bus and serves as an interface for connecting and programming various devices sharing a given protocol. As standard, all Neuron units are equipped with one RS485 bus - the exception is the Neuron 500 line with up to 3 RS485 bus ports. These units then can be connected to devices using up to three communication protocols.

Inputs and outputs

Depending on model, I/O groups can be equipped with digital, analog and/or relay modules, or combination of all types. Each type has its own specific features and usage.

  • Digital inputs are designed for reading of binary values (0/1, on/off, open/closed etc.) and are thus suitable for connecting switches, motion sensors,...
Read more »