Saturday, September 11, 2010

Something new to the DIY people

The automatic house closes all the windows, switches off all lights and controls the heating.

I found a component for my first prototye of my homebus. I needed to get a driver IC that can transmit serial signals from a microprocessor, e.g. an Atmel Mega8 or Microchip 16F628. I will build up some test circuits with the promising sounding "PCA 82C251 T" bus driver IC. I will let you know what I will find out.

The first aim is to switch around 20 sockets while Mega8 microcontrollers check if the devices are needed. For example the Power LED voltage of the PC is checked. The Power LED can have got three states:
- constant on: socket has to stay switched on (PC in use)
- flashing: socket has to stay switched on (PC in sleep mode)
- off: socket can be disconnected from power network (PC off)

This check saves standby costs. If the PC is going to be needed, you tell the microcontroller which connects the socket and turns on the PC via an optocoupler.

Let see what I can get done..