Selectrix® Arduino

With the help of an Arduino it is not too difficult to decode the Selectrix signal.

You need an interface (just to protect the arduino) like this one:

	The sx clock signal (pin 1 of the SX DIN plug - also called "T0") triggers the interrupt INT0 of the arduino (pin2), the data signal (called "T1" is sampled with another input (I'm using pin 4). The 20V signal on DIN-PIN3 is used for supplying the arduino with power - after conversion to a lower voltage. Be careful, 20 volts is a pretty high voltage for any microcontroller!
	this is the first PC board... To reduce the overall size, I did not make an Arduino "shield" but instead integrated the ArduinoProMini on the board (the ArduinoProMini already has a 5V regulator and a quartz etc on its small SMD board).

I moved the C-code for decoding into a library with the name "SX", an example program (this is "Arduino style") shows how to use it. I tried to keep the code very simple.

Download Arduino Library "Selectrix" (GPL) .

Although the code seems to work (test it yourself!), I'm not sure about the proper bit order of the SX signal (what is the definition of bit "0"?). I would be happy if you comment...

Selectrix is a registered trademark of Maerklin GmbH, Goeppingen, Germany.