Getting Started 2.0 Documentation

The important stuff

• Arming state must be HIGH on AUX1 for safety and feature reasons
• Be sure to flash both the TX and RX as the 1.x and 2.x protocols are incompatible.
• Update to elrsV2.lua even if you have previously updated with a release candidate.
• Users of SPI receivers (AIO boards) must update Betaflight. Updated firmware is available on the pull request. https://github.com/betaflight/betaflight/pull/10788

Enhancements

Lua Awesomeness

• Change all the things! Lua has been completely rewritten from the ground up to be dynamic based on the transmitter's target and include many new configurable options. Be sure to update to ElrsV2.lua as the old version will no longer work at all. #620
• Many configuration items are now stored per-model. Using the "CRSF Receiver Number" in EdgeTX/OpenTX you can create multiple models on the radio for different purposes. #765
• ENABLE_TELEMETRY is no longer determined at compile time, and will be enabled when Telemetry is received from the flight controller automatically.
• Model Match. Don't want to fly your quad with your fixed wing settings by mistake? Enable Model Match to be sure the receiver will only work with a specific model ID. See Model Match for more details.
• Show other devices (Flight Controllers and Receiver) in ELRS Lua script + allow editing of device parameters #977 #1021 #997

Switch 128 new ways

• Added Wide switch mode. Wide switch mode allows up to 128 position AUX channels (7-bit switches), and includes sending TX power to the flight controller. See Switch Config #821
• Removed 1-bit switch mode.
• Switch mode is no longer determined at compile time and is set by Lua (must be disconnected from the receiver to change this setting).

Improved Sync Behavior

• Syncing behavior has been improved in a number of ways for faster initial connection and more reliable reconnection after failsafe as well as being objectively more fun.
  • Sync channel has been moved to the middle of the band to hit the antenna sweet spot #797
  • Sync packets are sent up to 800% more frequently when "disconnected", and 20% less frequently when "connected", which creates more opportunities for the receiver to establish a connection. NO_SYNC_ON_ARM users are unaffected. #784
  • The FHSS cycle duration of 25Hz (Team900) and 50Hz (Team2.4) has been halved to double the effective chance of connecting and speed up rate cycling on startup.
  • The sync slot now rotates through all available FHSS slots to guarantee a sync packet will resolve any "nonce slip" (getting stuck at 75/50/25 LQ)
• Tired of "RecEIver still connected" when trying to turn off your handset? Disconnect timeout on the TX is now based on the current rate and telemetry ratio #785
• Fixed a bug where we would spend a large portion of the sync period without the radio in receive mode making it difficult to sync on faster rates. #1128

Fly without going outside

• Like to play SIMs? Now you can turn your ELRS module into a bluetooth joystick with the click of a button. In Lua V2 you will find the BLE Joystick option (only ESP32 based modules). #815

Dynamic Power

• The Lua now optionally sets the maximum power output and the output power can be reduced using the link telemetry (requires TLM Ratio to not be Off) Can be overridden with a switch. See Dynamic Transmit Power #762 #724 #812
• The power level where the fan is activated is also configurable via Lua to allow baking of brownies with your TX module.
• Add 250mW power option for SIYI FM30/FR Mini #841

VTx Administrator

• The V2 LUA script now has a folder called VTx Administrator. Here you can set your VTx band, channel, power, and pitmode. Pressing the Send button then forwards this information to the FC and onto the VTx and works with both SmartAudio and Tramp protocols. This information is also automatically sent when a new TLM connection is made e.g. when you plug in your craft. To use this feature, setup the FC VTx settings using the standard 48 index table. Power levels refer to the power index set by the FC. Also works with iNav's fixed function pipeline. #804

Backpack Support

• Backpacks are additional ESP8285 chips you will find on TX modules such as the Happymodel and NamimnoRC range. They allow for communication to peripheral devices such as VRx modules. What does this mean? When you make a VTx frequency change via the VTx Administrator this change will also be sent to the VRx module. The perfect use case is when setting up at a race event. You can set your VTx channel/band while in the pits, and then on power up at the block your VTx and VRx are automatically configured. Flashing of Backpacks is now supported by the ELRS Configurator. Backpack GitHub

Home WiFi

• Store your home WiFi credentials so your TX and RX can automatically connect to your home network when doing updates. No mucking about with access points and phones that don’t allow upload in captive portal mode! The WiFi manager will automatically fall back to creating an access point if the home network can not be found. #527
• Configurator can auto-detect ELRS devices on your network so you can directly upgrade them without even selecting the target type, which is great because Windows support for mDNS can be hit or miss.
• A connected receiver can now be forced into wifi mode using the Lua "Wifi Connectivity -> Enable Rx Wifi" command. The default AUTO_WIFI_ON_INTERVAL has been increased to 60 seconds due to this easy way to end the delay manually.
• A progress bar was added to the webui’s flashing process. What’s happening? Progress!

Telemetry Improvements

• Telemetry Boost automatically enables a TLM Ratio of 1:2 when doing MSP configuration via the Betaflight Lua or VTx Administrator, even if TLM Ratio is Off #786
• ActiveAntenna added to linkstats telemetry #725
• iNav Vario sensor added #977
• Added support for KISS Lua script #977
• Added support for yaapu telemetry script: thank you yaapu for the good cooperation to implement and tune this feature. #977

Pretty Things for your crotch

• Basic OLED support has been added with status information, to be expanded in future releases. #739
• For those devices with an RGB LED there is a nice unicorn rainbow startup and the LED shows different colors, flashing and fade in/out for different information. #585
• Both RGB and monochrome LED status have been unified across the RX and TX for a consistent experience. LED Status

Gotta go fast

• In addition to the current 115200 and 400k bauds available in your handsets Hardware menu, there are now MEGA BAUDS 921600, 1870000, and 3750000 options with ELRS V2 and EdgeTX 2.5. The faster bauds allow for a further reduction in end to end latency (~0.5ms per end) and improved Lua operation. The use of higher bauds depends on the TX module MCU, handset, and quality of inverters. STM32 based TX modules such as FrSky and NamimnoRC V1 will be limited to 1870000, while ESP32 based TX modules (all other ELRS modules) will be able to run 3750000 if supported by the handset hardware. #864 #640
• Gotta go slow: The RX now supports arbitrary baud rates for compatibility instead of the standard 420000 baud. KISS needs 400000, or an Arduino can be connected at 115200.

See what you're working with

• Accurate version number displayed in the webui (tag/branch and hash) along with the target name lets you know that flash worked.
• Lua displays tag/branch and hash as well, no more confused complaints about wtf version 010200 means.
• Target name is also verified before flashing, so CapnBry will stop flashing his X with Y firmware.

Direct PWM output

• Support for PWM servo output has been added with the PWMP target, for both DIY designs (5-6 channel) or the Matek ELRS-R24-P (5 channel).

Misc

• Adds IRegulatory_Domain_IN_866 Domain #683
• Regulatory_Domain_ISM_2400 has been removed from user_defines and is automatically used when building Team2.4 targets.
• Diversity switching has been improved by switching more quickly instead of being stuck on the bad antenna for too long.

Bug fixes

• NA… we squashed all those in V1! sweat-nervous.gif

New Hardware Targets

2.4GHz

• SIYI FR Mini RX as TX #746
• DIY_2400_RX_PWMP #998
• MATEK_2400_RX_PWM #1069
• BetaFPV 2400 Micro #1038
• Namimno Flash OLED #1032
• Happymodel Slim Pro renamed to Pro Series

915-868MHz

• DIY_900_RX_PWMP #998
• BetaFPV 900 Micro #1038
• Namimno Voyager OLED #1032

A note on versioning

The versioning scheme chosen by the ExpressLRS devs is based on the semantic versioning scheme. Where a version is defined as “major.minor.patch” major = major new feature and/or incompatible changes minor = minor features or enhancements and/or new targets patch = bug-fixes