I've been using 600mW 5665MHz FPV modules for HamTV and I wanted to overlay my callsign on the video stream.
There are several kinds of cheap modules to overlay data, based around the MinimOSD board. The firmware is
open source GPL3 and the first one I got to work on my setup was https://github.com/ShikOfTheRa/scarab-osd
This has many, many features, all of which are not needed for HamTV (false horizon? velocity and heading?)
So I gave the code a very severe prune and this is the result: it just displays the callsign and an
alternating +/- symbol, just to show it's still alive. I might add back the GPS, but displaying Maidenhead.
Bill Hill (M1BKF) <bugs@wbh.org> 2017-09-08