Connector blocks host MCUs to make electric loads listen, talk and act

July 24, 2013 // By Christoph Hammerschmidt
With digitalstrom, simple electrical appliances including luminaires, light switches and fuse boxes become intelligent and start to communicate. The technology also provides interfaces to smartphones and tablet computers, enabling owners to remotely control and monitor electricity consumers in their homes.

It looks like a simple terminal, but actually it is a computer: The basic building block of the digitalstrom concept contains an 8-bit AVR microcontroller along with a proprietary communications controller. These smart terminals are switches into the supply line and make the downstream appliance smart: its status can be read, it can be switched on or off, and, if it is dimmable, it can be dimmed from any place within the home or even by a smartphone with the appropriate app installed. For every basic appliance type (luminaire, roller shutter / sun blind, emergency, and access) there is a different type of smart lustre terminal with individual and global programmable functions. Likewise, motion, smoke, or rain detectors can be integrated into the system and trigger specific, defined actions.

Fig. 1: They look like dumb terminals, but actually they are tiny computers. In the digitalstrom world, a yellow terminal is dedicated to lighting applications, red is for safety / security applications, green means access control.

The lustre computers communicate through a proprietary powerline communications scheme with one or several servers in compact packages located in the fuse box. Called digitalstrom Meter in the digitalstrom terminology, these servers assume the role of the communication centre in digitalstrom's master/slave architecture. One server can connect via a protocol similar to DHCP to up to 128 slaves. In addition, the servers run the TCP/IP protocol stack to connect the smart home to the internet, effectively turning smartphones or tablet computers into remote controls. The server also runs a variety of apps provided by digitalstrom. Functions include clock timer, event messages or setting up specific user-defined scenarios. Appliances and devices can be connected at the discretion of the user. In the digitalstrom network, all nodes are within reach from anywhere; there are no limitations as to the implementation of functions as long as they comply with the physics of that device (a refrigerator cannot be