FEATURE GREEN TECHNOLOGY PI transforms energy harvesting
maintenance-free batteryless wireless solutions centrally controlled by a single- board computer. This board transforms the Pi into a wireless gateway for first smart home installations using energy harvesting wireless solutions. It enables the Raspberry Pi to communicate with thermostats and switches, to control systems such as temperature and lighting. This solution provides a bidirectional
John Corbett, UK Sales Director for EnOcean, uncovers how the Raspberry Pi is continuing to evolve with the latest Pi-connected energy harvesting wireless solutions and what this offers to wireless automation and control applications
T
he Raspberry Pi has become one of the most popular single-board
computers. The reason behind the Pi’s attractiveness is perhaps due to its programming flexibility and easy-to-use connectivity. The mini-PC provides the basis for many applications such as spreadsheets, Word processing, games and high-definition videos. That said, the Pi has tapped into many other areas besides education, including industrial control modules, robotics, automation and media centres. The single-board computers can be easily connected to several other communication technologies – to process, control and visualise data. This makes it optimal for automation processes and connecting with energy harvesting wireless solutions. Energy harvesting wireless technology
stems from a simple observation – where sensor data resides, sufficient ambient energy exists to power sensors and radio communications. Harvestable energy sources include: motion, indoor light and temperature differentials. These ever- present sources provide sufficient energy to transmit and receive radio signals between wireless switches, sensors, actuators and controllers, sustaining vital communications within a connected system. Instead of batteries, miniaturised energy converters generate power for the wirelessly communicating devices. This allows battery-less energy- autonomous sensors, switches and
16 MAY 2014 | ELECTRONICS
actuators which are ideal for home automation start-up enthusiasts. No cables are required to switch lights, control blinds and get sensor information like temperature, humidity or presence detection. Today, energy harvesting wireless technology is widespread providing solutions in the building automation sector, bridging the control of light, HVAC and other fields of building technology to smart buildings, smart metering and energy management.
STANDARD PROTOCOL The radio protocol is standardised as ISO/IEC 14543-3-10 and uses sub 1GHz frequency bands. This provides a safeguard against other wireless transmitters, whilst offering fast system response and elimination of data collisions. Telegrams transmitted by the protocol are less than one millisecond in duration, which is a minimum for switch commands, and are transmitted at a data rate of 125kilobits per second. The range of energy harvesting wireless sensors is about 300 meters in an open field and up to 30 meters inside buildings. The EnOcean Pi board now combines the benefits of both worlds:
The EnOcean Pi board combines the benefits of maintenance-free batteryless wireless solutions centrally controlled by the easy- to-use single-board computer, Raspberry Pi
radio interface at one end and a bidirectional serial interface at the other end. Radio messages are sent transparently through the serial interface to and from the Raspberry Pi board. In addition, control commands can be sent from the board, for example to configure the repeater functionality or to manage bidirectional communication. The board can act as postmaster for up to 20 bidirectional sensors using bidirectional communication. This board already comes with firmware
that automatically interprets EnOcean telegrams for communication between batteryless devices and any communication standard used by the Raspberry Pi. The firmware is available as source code, so developers can adapt the solution and conduct cross-compilations. The firmware offers a small selection of energy harvesting wireless application profiles and instructions for testing. Combined with EnOcean Pi, the
Raspberry Pi takes the role of a home server which receives and sends radio telegrams. This means it can, for example, receive temperature values periodically sent from a solar-powered wireless sensor module STM 330. This data can be visualised with any web interface connected to the Pi. The result of combining these two
“The result of
combining these two boards is a ready-made
smart home box, which can process data from batteryless wireless sensors and send the data ...”
boards is a ready-made smart home box, which can process data from batteryless wireless sensors such as temperature, presence, light intensity, or humidity to a PC, smartphone or tablet providing central control of a wireless connected house. Besides this, the duo can be used for a variety of applications including, gateways for cloud services or low-cost building automation
with an interface to all solutions based on the EnOcean wireless
standard.
EnOcean
www.enocean.com +49 8967 346 890
Enter 217 / ELECTRONICS
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36