Self-powered switch to control LED lighting

EnOcean has introduced its first energy harvesting wireless switch module for consumer applications such as the control of LED lighting systems.

EnOcean PTM switch module

EnOcean PTM switch module

The device which operates in the 2.4GHz ISM band, has a form factor which allows it to fit in a standard light switch.

The device’s electromechanical energy generator converts kinetic energy into electrical energy which is used to power to a wireless module.

EnOcean also has a range of self-powered 1GHz wireless switch modules used in the building automation and smart home sectors. With the 2.4GHz (IEEE 802.15.4) switch module, the supplier is addressing for the first time consumer LED lighting control applications.

“This will increase consumer awareness and demand for self-powered wireless solutions as an alternative to batteries,“ said Laurent Giai-Miniet, CEO, EnOcean.

Laurent Giai-Miniet, CEO, EnOcean describes how energy harvesting meets Raspberry Pi

To transform the Raspberry Pi into a smart home server integrating energy harvesting wireless solutions, the following accessories are needed: power supply (~1A) with micro USB plug, HDMI cable, SD card (e.g. 4GB), Ethernet cable or USB WLAN stick and an EnOcean Pi board.

As a first step, Raspian wheezy image (Debian Linux for Raspberry Pi) needs to be installed on the SD card. This is available for download at the website. After plugging the SD card to the Pi board and its configuration, EnOcean Pi needs to be connected on the Raspberry Pi’s top. As default, the serial port of the GPIO interface is used for console debug outputs. In order to use this port for EnOcean Pi, this feature has to be disabled first. In a next step, the connection can be tested with raw data from EnOcean Pi by using hexdump.

For this, EnOcean Pi provides a serial stream of EnOcean radio telegrams according to ESP3 protocol (EnOcean Serial Protocol 3.0). The protocol describes the serial communication between a host and energy harvesting wireless receivers. For remote control via TTY (e.g. PuTTY) or HTML server connections, the IP address of Raspberry Pi is needed.

Users can get the allocated IP address (e.g. by DHCP server) by typing in the command: “ifconfig”. After this, developers can start with the installation of a building automation server based on GPL software (General Public License) such as FHEM or openHAB. Instructions can be found on the according websites.

The EnOcean Pi accessory is supplied with free to download EnOcean Link Trial version middleware. It decodes and encodes data communication according to the EnOcean profile standard and executes device connection. The trial version offers a selection of application profiles as well as instructions, for testing the basic functionality of the software.

With these components, users now can start to use the Raspberry Pi-based home automation server to automate common tasks like switching lamps, scene illuminations or pulling blinds, measure and visualise power consumption, temperature and humidity. EnOcean Pi serves as a gateway controller to batteryless wireless applications.

This could be a solar-powered radio sensor (e.g. STM 330 temperature sensor or STM 320 reed contact sensor) which periodically sends values to be interpreted and displayed via the web interface. With the duo of Raspberry Pi and EnOcean Pi, developers can open up the world to energy harvesting wireless control in a few steps.

For more information

The switch is being shown at the Light+Building exhibition in Frankfurt this week.




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