RE1 Feature: OSD based Video Transmitter Configuration

Have you ever been annoyed by having to fiddle with dip-switches and buttons to configure your FPV video transmitter?

We have. And it sucks. So we’ve added a new feature to BrainFPV RE1 that allows you to easily configure your FPV video transmitter through the on-screen display (OSD) menu with no fuss. This feature currently works with video transmitters by Team Blacksheep and is essential for FPV racing and just awesome for FPV in general.

Why do we need different frequencies?

Video transmitters for FPV come in a variety of shapes and sizes from numerous manufacturers. The most popular ones operate in the 5.8GHz ISM band, which is the same band that is often used for WiFi and goes from 5725MHz to 5875MHz, so there is a total of 150MHz available. A typical analog FPV video feed requires about 20MHz of bandwidth and we need some frequency spacing between the feeds, so only 4 or 5 pilots can typically fly at the same time. This means that the FPV video frequencies have to be carefully allocated and pilots often need to change the frequency before they can fly.

If two pilots accidentally use the same frequency (or two frequencies that are too close together), there will be interference, and possibly casualties (of your drone).

Most FPV video transmitters allow changing the channel (i.e. frequency) using dip-switches or a button with LEDs to indicate the selected channel. The photo below shows some typical video transmitters.

Buttons and dip-switches suck

As you know, figuring out what frequency (or channel) you are on, and how to select a specific channel often requires some mental gymnastics and consultation of the video transmitter manual, which is super inconvenient. There is also the danger of being accidentally on the wrong frequency causing interference for another pilot who may already be flying (not a good way to make friends).

Enter Team Blacksheep SmartAudio

The Team Blacksheep (TBS) guys also got fed up with dip-switches and buttons, so they released video transmitters with support for “SmartAudio”, which allows other devices to configure the video transmitter through the audio cable. This technology is used in the TBS Core Pro OSD and the popular TBS Vendetta racing quadcopter, where the video transmitter channel and transmit power can be changed using the OSD menu.

However, until now, pilots who wanted to build their own custom racing drone had to resort to dip-switches and buttons, which feels like being in the stone age after having gotten used to configuring the video transmitter through the OSD menu with the TBS Vendetta.

Fortunately, the folks over at Team Blacksheep are awesome and sent us the specifications for their “SmartAudio” standard, so we could add it to the BrainFPV RE1 OSD. A few sessions of coding later, we added the “VTXConfig” module to dRonin (see GitHub pull-request). This feature works with both the “TBS UNIFY PRO 5G8” and the “TBS UNIFY PRO 5G8 HV” video transmitters.

Excited yet?

Setting it up couldn’t be simpler: Connect the audio signal to the Tx pin on the Serial Port of RE1 (or the Tx pin on any serial port of Brain, the previous generation product) and set the port to “VTX Config TBS SmartAudio”.

Note: The picture above shows the connection of a TBS – Unify Pro (not HV), which is powered by 5V. If you use the HV version, connect it to the “F output” of mPB to power the Unify Pro HV. Also, SmartAudio is only supported on SerialPort (UART1 in Betaflight).

After rebooting RE1, you will be able to configure the video transmitter through the OSD menu and display the frequency as well as the transmit power in the OSD:

Done and done. Yet another feature that no flight controller currently can do, but RE1. Welcome to the future.

Fly on :).

Martin