Implementation and Test of a Power-Line based Communication System for Electrical Appliances Networking Andrea Ricci ∗ , Valerio Aisa § , Ilaria De Munari ∗ , Valerio Cascio § and Paolo Ciampolini ∗ ∗ Dept. of Information Engineering, University of Parma, Parma, Italy. Email: andrea.ricci@nemo.unipr.it, {ilaria.demunari, paolo.ciampolini}@unipr.it § Wrap S.p.A., Fabriano (AN), Italy. Email: {Valerio.Aisa, valerio.cascio}@indesitcompany.com Abstract— This paper discuss the development of a low-cost, narrow-band transmission system, aimed at connecting digital appliances to a home network. The proposed approach is based on powerline communication (ULP: Ultra Low-cost Powerline), carried out on the power-supply wire between the appliance and the outlet. Through ULP, appliance can communicate with a transceiver node located at the outlet, the “smart adapter”, which, in turn, can flexibly route messages toward external control devices (e.g., for diagnostic purposes) or, more generally, toward a home control network. At the appliance side, such an approach allows for connectivity at extremely low costs, at the same time keeping independent of the actual home control network protocol (since different configurations of the smart adapter take care of it). To make practical their implementation on a variety of digital appliances, ULP communication functions have been implemented in a dedicated hardware device, conceived as a dedicated peripheral for a general-purpose microcontroller. In this work, details on the peripheral architecture and its implementation are given. A prototype of the peripheral has been developed, based on a FPGA board directly connected to the microprocessor bus. This closely emulates the perspective microcontroller architecture, and allowed for extensive testing of the device under realistic operating conditions. Complete characterization of ULP protocol has been carried out, estimating BER figures well below 10 -6 . I. I NTRODUCTION Microelectronic technology fostered the pervasive diffusion of digital controllers. Modern household appliances embed microcontrollers to manage all tasks; digital cores are used, for example, to control electric actuators and to manage sensor signals. Furthermore, digital domain computation allows for the deployment of innovative features. Among these new characteristics, connectivity is expected to become a standard in the next future. This will enable for innovative services like preventive maintenance, remote control and smart power management. Networking will improve functionality, safety, reliability and performance of appliances. To this purpose, the adoption of several communication protocols, either wired or wireless, had been proposed (Kon- nex [2], LonTalk [1], Ethernet [3], ZigBee [4]). However, high- priced communication nodes, typical of these solutions, pre- vent most of them from being effectively exploited for low- cost “white goods” networking. Moreover, the absence of uni- versal agreement on a recognized home-networking standard, makes the protocol selection a difficult task and leaves the field micro- controller micro- controller ULP peripheral CPU Digital Appliance Low-Cost Power-Line Communication Communication node ( PLC , ZigBee , WiFi , ...) AFE Smart Adapter AFE Home Network Fig. 1. Network structure. open to new smart solutions. A new approach has been pro- posed in [5] and [6], based on a novel network structure, which allows for each digital appliance to establish an ultra low- cost half-duplex power-line communication (called ULP: Ultra Low-cost Powerline) on its power-supply cord. A general- purpose communication node (called a ”smart adapter”, SA) located, for instance, at the outlet then acts as a bridge between the ULP communication and the actual home-networking protocols. Using this method, i) communication costs at the appliance side are kept at a minimum and, ii) communication with the specific home-networking protocol are delegated to the smart adapter, so that the internal appliance architecture does not care about standard protocols at all, and the same appliance may communicate with different networks just by exploiting the proper SA. Moreover, since appliance additional costs due to ULP are negligible, ULP features can be imple- mented on every produced item, regardless of its actual need of networking. As a side-effect, this provide an effective and inexpensive way for factory testing as well. In a previous paper [5] a preliminary FPGA-based imple- mentation for ULP peripheral supporting upstream commu- nication was introduced; in this paper, an improved solution will be discussed: some basics of the approach have been revised, aiming at lowering EMC disturbances, and at adding some functionalities. In the following, the novel architecture is described, aiming at implementing the ULP algorithms into a dedicated microcontreller peripheral. Within this perspective, 1-4244-0113-5/06/$20.00 c 2006 IEEE. 239