The Telegea Smart Hub is designed to be a gateway between the real world and the communication network targeted mainly at IoT applications. It is a custom hardware built around the RaspberryPi Compute Module and therefore compatible with the software from the RaspberryPi ecosystem. It provides a number of standard interfaces for sensors to acquire the data and actuators to control connected devices. Easy to use connectors and a DIN rail case are provided to ease installation. If needed, functionality can be extended with add-on modules.

The Smart Hub connects to the communication backbone via Ethernet or Wifi (optional) and therefore can provide the data to a cloud service or be controlled remotely.

It is completely user configurable, so different numbers of sensors, actuators or external equipment can be combined with each other. This flexibility allows for many different deployment scenarios which goes from a simple data logging device to a complete smart home solution.

The Telegea Smart Hub and all of its hardware components are well documented. Specifications and data sheets are freely available. Each component is supported by open source drivers and additional software that can be obtained free of charge and modified to fit specific needs.

Typical applications

The Telegea Smart Hub is an excellent choice as a Smart Home server device. It can interface with many types of sensors which provide data from around the house. Relay cards can be connected to switch lights, move motorized blinds, open/close doors etc. And it has enough computing power to run the user web interface and the automation rules engine which makes the whole system "smart".

OpenHAB and Home Assistant are two of the most popular open source Smart Home projects which are being developed by their respective communities who also offer support to their user base. Both systems have been tested on the Telegea Smart Hub and will transform this hardware into a fully fledged home automation controller that you can customize to fit your needs.

Technical Insights

The Smart Hub is realized as a double sided 4 layer printed circuit board. All materials and components are lead free and follow the RoHS guidelines.

The form factor is 3 times credit card size which allows to fit all necessary components and connectors on the PCB and leave some space for add-on modules.

The Smart Hub provides an easy to use and robust hardware base for IoT and Smart Home tasks. The industrial grade integrated eMMC flash memory provides reliable storage for the Operating System code and configuration data. Screw terminals allow easy and robust connections of sensors, digital and analog inputs and communication busses.

The integrated Real Time Clock keeps track of time and date during short power off periods and reboot as well as unavailability of a network time server. An on board push button and led can be programmed to be used as means of manual user interface if network connection is not available.

The Smart Hub is a typical server device which does not need be in sight of the user and therefore can be conveniently installed in an electrical switchboard. Its size fits a commercial Camdenboss CNMB/9 DIN rail enclosure. As power supply a industry standard 24VDC or 24VAC can be used via the front screw terminals. But for use with a consumer phone charger also a microUSB connector for 5VDC power input is provided at the back of the board.

A dedicated on-board circuit allows measuring the input voltage via 2 of the integrated ADC channels which provides valuable data for the systems health check. If the board is powered with AC power via an AC/AC transformer, even the effective mains voltage can be derived from the ADC measurements.

The integrated digital temperature and humidity sensor provides instant information about the environmental conditions inside the switchboard without the need of extra cabling. This data can be used to raise an alarm in case of exceeding the operating condition limits.

Specifications

• Processor: BCM2837 System on Chip (Quad core Cortex A53)
• Storage: 4GB eMMC
• Memory: 1GB LPDDR2 RAM
• Communication: Ethernet port (100BASE-TX)/RS485 serial port/RS232 serial debug port/Wifi 802.11 b/g/n a 2.4 GHz (optional)
• Inputs: 6 digital inputs via screw terminals (for dry contacts or S0 interface)/4 analog inputs (0-5V) via screw terminals/Dallas 1-wire bus via screw terminals
• On board sensor: SHT21 temperature and humidity sensor
• Expansions: 2 USB host ports/1 RJ14 connector for I2C bus peripherals/1 RJ14 connector for SPI bus peripherals/1 XBee module compatible connector for ZigBee and other RF modules/3 expansion headers with additional GPIO, SPI and I2C bus connections
• Power supply: 5VDC via micro USB connector/24VDC/24VAC via screw terminals
• Other: Real Time Clock with integrated battery/256 byte EEPROM for persistent product data storage/Programmable Push button/Programmable yellow LED/USB OTG port for flash programming
• Operating System: Raspbian Jessie Lite, Linux kernel 4.9.x and later
• Dimensions: 155x86mm

Includes the following

• Main PCB
• Raspberry Pi Compute Module 3
• DIN rail case