The UniPi 1.1 and 1.1 Lite are a simple and inexpensive expansion boards for the Raspberry Pi computer, allowing it to function as a programmable logic controller (PLC). It is also the direct predecessor of the UniPi Neuron product line.
UniPi 1.1 is an extension board for the Raspberry Pi minicomputer, allowing it to function as a programmable logic controller (PLC). It is a simple and inexpensive controller suitable for the use in Smart Home, BMS systems (Building management system) and for the development of innovation in the field of Internet of Things. As an example may be building heating automation, automatic light switching, watering systems, garage and gate control and other applications (read more in our references and Smart Home applications description). UniPi is an affordable control unit which can help you increase comfort and decrease operation costs.
- 8 × changeover relays(rated 250V AC/5A or 24V DC/5A)
- 12+2* galvanically isolated digital inputs (triggered by 5-24V DC)
- 2 × 0-10 V analogue input
- 1 × 0-10 V analogue output
- 1 × 1-Wire port (suitable for connection of for example digital 1-Wire thermometers or other 1-Wire sensors)
- 1 × I2C port for extension
- 1 × Battery slot for RTC (Real Time Clock)
- 1 × UART port for external serial communications (it is possible to connect directly via serial adapter)
*Digital inputs 13 and 14 are not accessible by default. To use them, please follow this manual.
UniPi 1.1 Lite
UniPi 1.1 Lite is a smaller and simpler variant of the UniPi 1.1, designed for the smallest automation projects. When compared to the UniPi 1.1, it features fewer I/O's but is more compact and cheaper.
- 6 × changeover relays rated 250V AC/5A or 24V DC/5A
- 6 × galvanically isolated digital inputs triggered by 5-24V DC voltage with a minimum pulse length of 5ms
- 1 × 1-Wire port for connection to 1-Wire thermometers and other sensors
- short circuit LED indicator
- compatible with Raspberry Pi 3, Raspberry Pi 2 a Raspberry Pi B+
- connection with Raspberry Pi via a supplied ribbon cable
- possible to equip with DIN rail mounting and plastic cover
- requires an external 5V 2.5A power supply with 2.1mm DC jack
UniPi v1.1 and 1.1 Lite are officially compatible with Raspberry Pi model B+, Raspberry Pi 2 model B and with Raspberry Pi 3 model B.
How does it work
Raspberry Pi serves as a CPU of the control unit. Control software is stored on the SD card inserted into the computer, the Raspberry Pi itself then controls and processes data from I/Os. All I/Os and communication interfaces are connected to the Raspberry Pi's CPU - either directly through GPIO or indirectly via I2C. Raspberry Pi also provides network connection through 10/100Mbit Ethernet and four USB 2.0 ports. USB can be also used for connecting the USB-RS485 converter for communication with external devices using the Modbus protocol.
Relay outputs are connected to the processor over I2C. Over it is possible to connect extension modules in case of need for additional inputs/outputs.
1-Wire channel allows connection of 1-Wire sensors and devices. Typically is suitable for connection of digital thermometers, which are affordable and easy to install.
Inputs and outputs
Depending on the model, I/O groups can be equipped with digital, analogue and/or relay modules, or a combination of all types. Each type has its own specific features and usage.
Digital inputs are designed for a reading of binary values (0/1, on/off, open/closed etc.) and are thus suitable for connecting switches, motion sensors, window or door magnetic locks etc.
Digital outputs can be used to control binary state devices, such as lightning switches, window shutters control, remote door control etc.
Analogue inputs are used to receive either 0-10V voltage or 0-20mA current signals. Alternatively, they can be used for reading data from corresponding sensors, such as resistance thermometers. The user can adjust the input mode via corresponding control software.
Analogue outputs are used for control of external devices such as three-way valves or heat exchangers via 0-10V voltage or 0-20mA current signals. Analogue outputs allow current or voltage regulation - alternatively, Group 1 inputs can be used in combination with resistance thermal sensors.
Relay outputs are designed for switching two-state devices via alternating or direct voltage. Relays thus can be used to switch boilers, water heaters, electric motors or other stronger relays. Neuron unit relays are designed for 5A maximum current and 250V alternating/30V direct voltage.
UniPi v1.1 is compatible with a wide variety of software. For the UniPi 1.1/1.1 Lite we recommend either our open source driver EVOK or our advanced control software, Mervis. You may also be interested in an introduction to choosing software, where other compatible software platforms are mentioned.