Betaflight VTX Tables Setup

Betaflight 4.1 introduces a new feature - VTX tables. If you can not switch channels or output power on your SmartAudio or IRC Tramp enabled video transmitter out of the box, VTX tables are probably the reason.

Instead of being pre-configured as in the previous Betaflight versions the user now has to configure the frequency tables themselves. It might at first seem like a hassle but it also has some benefits.

The manufacturer of your video transmitter or AIO combo should provide you with a configuration file that you simply load via the Betaflight configurator and your VTX tables are set and you are ready to use SmartAudio or IRC Tramp - nothing else needed. If this is the case you are lucky and are done now.

You can check the betaflight wiki or the manufacturers website. If there is a matching JSON file for your video transmitter you are good to go, just download it and load it in the configurator in the Video Transmitter tab.

In most cases you can just flash the appropriate file for your protocol and version from the betaflight wiki and you should also be good to go (even if you have a different VTX than listed there). You might need to adjust your power levels though.

  1. Base config
  2. Adding a custom band
  3. Power levels 3.1. IRC Tramp 3.2. SmartAudio
  4. Default settings

Base config

If there is no ready to use config file that matches your needs, there are a couple of things you need to do. First of all, add a frequency table. This can be done via CLI or manually via the configurator in the Video Transmitter tab.

The route via the CLI is the quickest - use this as your starting point and double check with the actual capabilites of your video transmitter:

IRC Tramp

If you want the US channel table, copy and paste the following code into the CLI:

vtxtable bands 5
vtxtable channels 8
vtxtable band 1 BOSCAM_A A CUSTOM 5865 5845 5825 5805 5785 5765 5745 5725
vtxtable band 2 BOSCAM_B B CUSTOM 5733 5752 5771 5790 5809 5828 5847 5866
vtxtable band 3 BOSCAM_E E CUSTOM 5705 5685 5665 0 5885 5905 0 0
vtxtable band 4 FATSHARK F CUSTOM 5740 5760 5780 5800 5820 5840 5860 5880
vtxtable band 5 RACEBAND R CUSTOM 5658 5695 5732 5769 5806 5843 5880 5917
save

If you are from the EU, copy and past the following into the CLI:

vtxtable bands 4
vtxtable channels 8
vtxtable band 1 BOSCAM_A A CUSTOM 5865 5845 5825 5805 5785 5765 5745 0
vtxtable band 2 BOSCAM_B B CUSTOM 5733 5752 5771 5790 5809 5828 5847 5866
vtxtable band 3 FATSHARK F CUSTOM 5740 5760 5780 5800 5820 5840 5860 0
vtxtable band 4 RACEBAND R CUSTOM 0 0 5732 5769 5806 5843 0 0
save

SmartAudio

If you want the US channel table, copy and paste the following code into the CLI:

vtxtable bands 5
vtxtable channels 8
vtxtable band 1 BOSCAM_A A FACTORY 5865 5845 5825 5805 5785 5765 5745 5725
vtxtable band 2 BOSCAM_B B FACTORY 5733 5752 5771 5790 5809 5828 5847 5866
vtxtable band 3 BOSCAM_E E FACTORY 5705 5685 5665 0 5885 5905 0 0
vtxtable band 4 FATSHARK F FACTORY 5740 5760 5780 5800 5820 5840 5860 5880
vtxtable band 5 RACEBAND R FACTORY 5658 5695 5732 5769 5806 5843 5880 5917
save

If you are from the EU, copy and past the following into the CLI:

vtxtable bands 5
vtxtable channels 8
vtxtable band 1 BOSCAM_A A FACTORY 5865 5845 5825 5805 5785 5765 5745 0
vtxtable band 2 BOSCAM_B B FACTORY 5733 5752 5771 5790 5809 5828 5847 5866
vtxtable band 3 BOSCAM_E E FACTORY 0 0 0 0 0 0 0 0
vtxtable band 3 FATSHARK F FACTORY 5740 5760 5780 5800 5820 5840 5860 0
vtxtable band 4 RACEBAND R FACTORY 0 0 5732 5769 5806 5843 0 0
save

The EU version is different in such a way, that specific frequencies will simply not be available in order to be compliant to EU regulations. The frequencies marked in bold are the ones that will not be available if you use the EU configuration. The frequencies that are crossed out can be used under certain circumstances with the proper licence in the US:

Band 1 2 3 4 5 6 7 8
Boscam A 5865 5845 5825 5805 5785 5765 5745 5725
Boscam B 5733 5752 5771 5790 5809 5828 5847 5866
Boscam E 5705 5685 5665 5645 5885 5905 5925 5945
Fatshark F 5740 5760 5780 5800 5820 5840 5860 5880
Raceband R 5658 5695 5732 5769 5806 5843 5880 5917
IMD6 5732 5765 5828 5840 5866 5740    

CAUTION: Adjust the frequency table to the capabilities of your video transmitter. Not all transmitters support every frequency. Some need to be unlocked in order to support certain frequencies. Almost every VTX or AIO system comes with a table of supported frequencies. Set frequencies to 0 that are not supported by your video transmitter or that are not allowed in your region.

Adding a Band

CAUTION: this will only work on video transmitters where the CUSTOM mode works. It will work on all IRC Tramp devices, but not all SmartAudio devices support setting custom frequencies - you will simply have to try it out or ask the manufacturer of your VTX.

One of the great things with VTX tables is, that you can add custom bands. You could for example add a custom band for the frequencies you use most often - or for example add a configuration with the optimally spaced frequencies for six pilots - called IMD6 which is also often used for races. In order for IMD6 to be your sixth band copy/paste the following into the CLI:

vtxtable bands 6
vtxtable band 6 IMD6 I CUSTOM 5732 5765 5828 5840 5866 5740 0 0
save

Commands

Let’s briefly discuss the commands and what they do exactly:

The first command (vtxtable bands n) allows you to set how many bands you want to have available. You can increase this later on if you wish. The second command (vtxtable channels n) configures how many channels each of those bands should consist of.

The following lines each describe the configuration for a band:

vtxtable band 1 BOSCAM_A A CUSTOM 5865 5845 5825 5805 5785 5765 5745 5725

1 represents the band. BOSCAM_A is the long name for the band, this can be anything you like, but for the sake of consistency we keep this to the default names. A is the short name, this has to be one character but we again keep it to the default character the band is known under.

The next option CUSTOM could also be FACTORY. This setting is responsible for letting the flight controller know how to set the channels on the VTX. When set to FACTORY the internal channel table of the VTX is used. Not all VTX have this internal channel table, others on the other hand can only be used with FACTORY mode.

Example: If we want to set the VTX to A1 (5865MHz), the FC would send 00 (first channel on the first band - counting internally starts from 0) when in FACTORY mode and 5865 when in CUSTOM mode, to the video transmitter in order to switch the frequency.

CAUTION: When changing this option you need to power cycle your video transmitter or your changes will not have any effect. Also be aware that most SmartAduio transmitters will only work in FACTORY mode.

The following eight values are the frequencies corresponding to the channels on the chosen band. Frequencies which should not be available are simply set to 0 (When using the FACTORY mode, those frequencies actually do not really matter, I would still recommend to set them according to the channel map of your video transmitter to avoid confusion).

Power levels

The channel maps were the easy part, the power levels are a little bit more complicated.

For this you have to at first know how many different power levels your VTX supports and in case of Smart Audio you also need to know the exact version.

IRC Tramp

The IRC Tramp protocol is a bit easier to configure than SmartAudio. You can again to this via the configurator by manually adding power levels, or simply via CLI:

vtxtable powerlevels 5
vtxtable powerlabels 25 100 200 400 600
vtxtable powervalues 25 100 200 400 600
save

The first line sets the amount of power levels, this has to match the amount of power levels your video transmitter supports.

The next line sets the Labels of the power levels. You can set this to anything, but I would highly recommend to simply set it to the actual power output - be careful you are limited here to four characters.

The third line sets the values that are sent to the VTX to set the power level, with IRC Tramp those are the power levels in mW.

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SmartAudio

SmartAudio has different versions and depending on the version, you have to set the power values slightly differently.

If you are not entirely sure which protocol or version your VTX is using, you can easily find that out via Betaflight - although we will be using blackbox functionality you do not need any means of actually logging:

  1. Go to the Blackbox tab
  2. Set Blackbox debug mode to SmartAudio
  3. Hit Save and reboot
  4. Enable Expert mode in the top section of the configurator
  5. Switch to the Sensors tab
  6. Check the Debug box and deselect everything else

Make sure that your props are off and power up your quad - we need the video transmitter to be powered on. You should now see that the values on the right change. Debug 0 shows the smart audio Version, depending on the output you have the following version:

Value Smart Audio
100 1.0
116 1.0 unlocked
200 2.0
216 2.0 unlocked
300 2.1
316 2.1 unlocked

Debug 1 shows the band and channel as a numerical representation if you are using FACTORY mode. Debug 2 shows the current frequency if you are in CUSTOM mode.

Unlocked means that you will be able to use all frequencies and power modes. Please check the manual of your video transmitter on how to unlock it.

SmartAudio 1.0

For this version of SmartAudio there are “recommended” power values. This might make it a bit more complicated in some cases, the recommended power values are:

Output power (mW) Power Value
25 7
200 16
500 25
800 40

Example: Your video tranmitter has the power levels 25, 200 and 500. Vial CLI you would set them like this:

vtxtable powerlevels 3
vtxtable powerlabels 25 200 500
vtxtable powervalues 7 16 40
save

SmartAudio 2.0

SmartAudio 2.0 devices are the easiest to set the power values. Those devices have an internal lookup table: The power values are numbered from 0 in ascending order corresponding to the actual output power.

Example: Your video transmitter has the power levels 25, 50, 200 and 500. The power values would thus be 0, 1, 2 and 3. Via CLI you would set the following:

vtxtable powerlevels 4
vtxtable powerlabels 25 50 200 500
vtxtable powervalues 0 1 2 3
save

SmartAudio 2.1

This version uses yet another variant for power values - the output power in dBm. Those values can be queried via the CLI which makes it a bit more easy:

vtx_info

Example: The output of the above command is:

level 14 dBm, power 25 mW
level 20 dBm, power 100 mW
level 26 dBm, power 400 mW

and you would set the power levels via CLI like so:

vtxtable powerlevels 3
vtxtable powerlabels 25 100 400
vtxtable powervalues 14 20 26
save

Setting Defaults

After you are done with the channel table and power level setup it is a good idea to set the defaults your video transmitter should start up with. This can also be done in the Video Transmitter tab:

In this case I set the defaults to use Raceband on channel 8 with an output power of 25mW.

Here you can also decide to setup pit mode if you want to use it. When pit mode is enabled the quad will power up with very low output power to not knock anyone out of the air. You can then exit pit mode by for example arming the quad or having pit mode on a dedicated switch.

Chris is a Vienna based software developer. In his spare time he enjoys reviewing tech gear, ripping quads of all sizes and making stuff.

Learn more about Chris, the gear he uses and follom him on social media:

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