Summary of TINYOSD & TINYFINITY – A TINY OPENSOURCE VIDEO TX WITH FULL GRAPHIC OSD
The author releases open-source firmware for a custom full-graphic OSD (tinyOSD) and a compact 16x16mm VTX board (tinyFINITY). This integrated solution uses an STM32F3 microcontroller to handle OSD generation via software, featuring DMA support. The design includes a modified Betaflight firmware for communication and integrates a RTC6705 video transmitter directly onto the PCB.
Parts used in the tinyFINITY Project:
- STM32F3 microcontroller
- RTC6705 video transmitter
- Modified Betaflight firmware
- 16x16mm PCB
- Surface mounted ceramic antenna (preliminary)
Merry belayed Christmas and a happy new year everyone. I know, I am running a tiny bit late. My original plan was to release the tinyOSD and tinyFINITY sources ready for Christmas but then the usual things got into the way and I had to postpone this post. But here it is: I am releasing my sources of my custom full graphic OSD with insane update rates to the world. But that’s not all! I am also releasing a custom 16x16mm VTX design that includes all the hardware to run the tinyOSD firmware on it. But let’s step back and let me tell you what this is all about. But be warned, this is going to be a very long post…
The basic idea
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:
As I like fully integrated solutions I started to work on a new PCB design that includes a RTC6705 video transmitter and my tinyOSD into one tiny 16x16mm board called tinyFINITY. The image shows a preliminary version where I tested a surface mounted ceramic antenna instead of the usual wire or whip-antenna (which was rejected in later designs because of the poor performance):
Read more: TINYOSD & TINYFINITY – A TINY OPENSOURCE VIDEO TX WITH FULL GRAPHIC OSD
- Why was the STM32F3 selected?
It was chosen due to its availability in small packages and necessary features like DMA. - What is the size of the tinyFINITY board?
The board measures 16x16mm. - Does the project use hardware or software for OSD generation?
OSD generation is handled in software using fast microcontrollers. - Can I modify the firmware for this project?
Yes, the author integrated full communication into a modified Betaflight firmware. - What type of antenna was tested initially?
A surface mounted ceramic antenna was tested in a preliminary version. - Why were wire or whip antennas rejected?
They were rejected because they offered poor performance compared to other options.
