This is a tiny open source video transmitter with integrated graphic OSD from Simon Schulz @ fishpepper.de
Some time ago I got annoyed by the available OSD solutions and I started to look for alternatives. Nowadays small micro controllers are fast enough and include fancy features like DMA so that the OSD generation can be handled in software. I selected a STM32F3 due to the availability in small packages and the necessary features I needed and got working. In May 2017 I posted a first preview of my tinyOSD development on my blog. That time it was running on a tiny PCB and was meant to be inserted between your camera and video transmitter. I got up to a point where I had integrated full communication into a modified betaflight firmware and could do all kinds of fancy animations:
tinyOSD & tinyFINITY – a tiny opensource video tx with full graphic OSD – [Link]