SCART Widescreen detector

Hi,

I'm in the process of making a PVR out of an old PC and have a cable box connected via SCART->composite cable to a WinTV PVR-350. This makes it impossible for the PVR to check if the video is in 16:9 or 4:3 which is something i'd like it to know. From looking on the net I can't find anything that shows how to do this so figured I'd have to make something which brought me to here.

From wikipedia pin 8 of the SCART cable will 4.5 to 7v for a 16:9 picture and 9.5 to 12v for a 4:3 picture. I measured 6v and 12v from the device i'd be using if it helps.

Firstly, is something like this possible with the arduino boards? If so, can someone describe what I'd need to do this?

thanks,
Mike

The Arduino board has 6 analog input pins that can be used to measure voltage wired to their pins. However the range of voltage that it can be safely measured directly is 0-5vdc.

So to read the value from your SCART cable on a Arduino, you first have to connect your pin it to a simple two resistor series voltage divider such that 0-12v applied to the top of the resistor string would read out as 0-4vdc at the junction of the two resistors. A 8k and 4k resistor should work well. The bottom of the resistor string goes to circuit common (ground). Then it would be up to you creating a progam that reads the voltage and takes the action (or justdisplay) that you wish.

It's a simple slam dunk for an Arduino.

Good luck.