Friday, September 24, 2010


The Homebus project is working! Three 82C251 are connected together. They connect the PC via USB/serial converter, a Dell Axim x50v and an Atmel Mega8. All 3 devices are able to communicate at 19200 baud.
Great! More to come..

Wednesday, September 15, 2010

Rally Master Pro removed!

Today Rally Master Pro was removed again from the PlayNow Store. Perhaps several people were experiencing the download issues.

Let's see when it comes back..

Monday, September 13, 2010

Taxi sheet music encrypted ;)

By the way, I just found out: the music piece printed on the Chopin taxi is the "Nocturne in B flat minor"

Have fun!

Sunday, September 12, 2010

Homebus analysis

I can confirm the 82C251 works nice. I haven't made a communication get to work due to the lack of a receiver circuit. The output provides a differential signal that seems to be stable enough to get transported over some metres of loose wire. More to come...

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..