In order to be able to add information to my PAL video signals I looked for a simple
circuit that can do that. I found the PicoOSD (" Overlay Superimposer Device ").
This circuit with only a tiny 12F683 PIC superimposes information
(like text and clock info ) over an existing PAL composite video picture.
I built the experimental circuit (which is only the pic, 25 MHz xtal and 2 15 pF capacitors) on a breadboard.
After programming the 12F683 the circuit worked immediately.
In the picture you see on top of the screen the elapsed time info. This is what the pico-osd does.
The clock info on top of the screen comes from the pico OSD. I am impressed!
Now the real challenge comes with reprogramming the source code in order to make my callsign and QTH locator visible. Not so easy since the program is written in " C ".
Experimental OSD on breadboard
Also have soldered the circuit on a piece of veroboard and now must integrate
the small circuit into the existing video switch/pattern generator.
OSD on vero-board
All the details:
Compliments to Bruno Gavand who develloped this project. Amazing what a 50 cents PIC can do for you !
Elapsed time shown on scene of "Bladerunner" with Rutger Hauer