ExpressLRS 4.0 is lastly right here. This can be a main replace with significant enhancements in efficiency, flexibility, and reliability—nevertheless it additionally introduces necessary compatibility adjustments you might want to perceive earlier than upgrading. In case your present setup is working completely, it’s possible you’ll not must improve. But when a number of the new options and enhancements are interesting to you, make certain to backup your config earlier than continuing.
Not Suitable with Older Variations
When you set up ExpressLRS 4.0, it can NOT work with:
- Units nonetheless operating ELRS 3.x, 2.x, or 1.x
- Older STM32-based {hardware}, together with:
You could replace each your transmitter (TX) and receiver (RX) to V4 for them to attach. They won’t talk in any other case.
Doesn’t Work with SPI Receivers (But?)
Some AIO flight controllers utilized in whoops have built-in SPI receivers. These are nonetheless operating ELRS 3.x code and won’t work with V4 but.
Since SPI ELRS firmware is built-in into Betaflight, assist is determined by a Betaflight replace first.
There isn’t a point out within the 4.0 launch notice that SPI receivers are being deserted, so I presume it’s solely momentary. In case you are utilizing SPI receivers, don’t replace to ExpressLRS 4.0 but.
What’s New in ExpressLRS 4.0
Get the total launch notice right here: https://github.com/ExpressLRS/ExpressLRS/releases. Right here’s a abstract.
Select Your Personal Arming Change
Beforehand, Channel 5 had for use for the arm change.
Now:
- With the choice arming technique, you possibly can assign a particular change for arming.
- Channel 5 turns into a traditional usable channel once more.
- Setup is extra versatile and handy.
- Requires EdgeTX 2.11.0 or increased
Higher Dynamic Energy
ExpressLRS now makes use of a wiser algorithm for dynamic energy.
This implies:
- Energy adjusts extra intelligently.
- Your sign stays sturdy with out always blasting most output.
- Higher battery life in your radio.
- Extra secure Hyperlink High quality (LQ) when utilizing dynamic energy.
Automated Antenna Mode
Earlier than, you needed to manually choose antenna modes (Gemini, Ant1, Ant2, Change).
Now, the transmitter and receiver determine it out routinely. No extra guessing or handbook changes—it simply works.
What’s Gemini Mode? https://oscarliang.com/expresslrs-gemini/
Full Energy DJI Air Unit And not using a Flight Controller
This can be a massive one for mounted wing customers who don’t use a flight controller.
It’s recognized that DJI air items don’t use full energy when it doesn’t detect an arm sign (though when energy is ready to max). ExpressLRS receivers can now ship an arm sign on to DJI Air Models to set off full transmission energy—no flight controller required.
Sooner Telemetry
Telemetry is the information your drone sends again (battery voltage, GPS, sign power and many others).
V4 enhancements:
- Telemetry velocity is quicker.
- Knowledge switch is extra dependable.
- “Sensor Misplaced” warnings are diminished.
When utilizing Gemini mode, telemetry bandwidth is sort of doubled.
New Internet Interface (WebUI)
The configuration webpage has been redesigned:
- Cleaner format
- Simpler to make use of
- Higher organized
Performance stays comparable—simply extra polished and user-friendly.
Expanded Servo & Output Choices (Superior Customers)
For pilots utilizing PWM receivers or particular setups:
- Wider servo output vary (500–2500µs)
- Expanded failsafe vary
- DSHOT 3D assist
- Extra packet modes (particularly for LR1121 {hardware})
When you don’t know what these are — you most likely don’t want them
Lua Script Change
You must also replace the ExpressLRS LUA script in your radio.
The lua script is now referred to as: elrs.lua
Delete older variations similar to:
This prevents duplicate ExpressLRS instruments from showing in your radio.
Essential: Settings Might Be Wiped When Upgrading
Upgrading to V4 adjustments the interior filesystem. Consequently, modified settings in WebUI could also be erased.
It is best to again up your configuration earlier than updating. To do that, obtain the {hardware}.json file from the webUI earlier than updating after which changed after updating.
Remaining Ideas: Ought to You Replace?
ExpressLRS 4.0 is a serious replace with important enhancements and new options. Nonetheless, it additionally breaks compatibility with older firmware variations and sure {hardware} (similar to STM32-based gadgets, and SPI receivers for now).
Earlier than upgrading:
- Be sure your {hardware} is supported.
- Again up your present configuration.
- Replace each TX and RX collectively.
In case your present setup works completely and not one of the new options are important to you, there’s no pressing must improve. Hold flying and keep away from trouble. When you determine to replace, do it rigorously—and ensure all the pieces is appropriate first.