Pi Testcard

7 Sep 2016

A recent project was delivered to me with a problem with its LCD screen. In the process of testing it I wanted to generate a composite video signal. After looking at some ideas involving Arduino and resistor dividers I came across some examples of raspberry Pi testcards, specifically RPI - ATV

I had an original Pi model B which has an RCA socket with composite out so that was ideal for my task.

To get the testcard to work I downloaded a suitable picture and added my text to it. I then installed the python script into the /home/pi/atv folder and added my image and a dummy sound file into the /home/pi/atv/images and /home/pi/atv/sounds folders.

I tweaked the python script not to use the internal generator and also to load the first image.

#don't always start with internal picture
internalPicture = false
loadimage("1")

To get the generator to start up automatically, I had tried using rc.local but that did not seem to work. I had a bit of help from fvan who suggested cron would work.

To add the cron job I ran the following which prompted me to pick and editor to edit the file.