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Tuesday 29 May 2012

Internet controlled appliances



According to their final year project report, Adam and Jeremy took on the challenge of designing a system that would make it easy to control appliances from the Internet. We’ve seen the concept many times before; it involves some method of switching mains power and connecting that mechanism to the Internet. This design is both well planned and nicely executed.


We’re always very interested in the power switching for a project like this. It’s good that an approved electrical box houses all of the high-voltage parts in the project. Here a GA8-2B02 solid state relay switches power between the incoming cord and the two outlets. We didn’t get a look in the box, but hopefully there’s a partition between those wires and the low-voltage control wiring which uses a standard 3.5 mm audio jack as an interconnect.
An ATmega644 drives the control signal for the relay. It’s connected via Ethernet cable to the Internet through the use of an ENC28J60 chip which takes care of LAN communications. This is essentially a light-weight web server that will be easy to adapt to receive commands from just about any web-connected sender.

2 comments:

Taral Shah said...

Can i get some info about the software control that handle this task? I meant what is the end terminal device? on what language script does it work etc..info

Rushi Gajjar said...

The PowerManager system is effectively able to run IP, TCP, and HTTP stacks on an AtMega644 MCU and interface these layers with the physical layer on an ENC28J60 Ethernet controller through SPI. All of this is done given the memory and processing constraints of the AtMega.