Getting Started 3.0 Documentation

The important stuff

• Arming must be on AUX1 for safety and feature reasons, having this fixed allows us to maintain small packet sizes and deliver better aux channel options
• Be sure to flash both the TX and RX.
• Lua script MUST be updated to elrsV3.lua and is backwards compatible with 2.x. Get it here: Lua

Compatibility

This is a new major version, 3.x, and like previous major versions the software is incompatible with the previous major versions, ExpressLRS 1.x and 2.x. TXes running 3.x software only work with RXes running 3.x software-- both sides must be upgraded. SPI RXes all currently run 2.x and will not work with a 3.x TX.

Users of SPI receivers (AIO boards) maintain compatibility with currently available V2 RF modes. Flight controllers can be updated from PR https://github.com/betaflight/betaflight/pull/11783 or wait until merged into BF master.

Packet types and RF smarts

• FLRC - The F is for Fast (modulation) and lower latency, but a shorter range than our normal modes. Our version can still easily do +10km and comes in 500Hz and 1000Hz flavors https://github.com/ExpressLRS/ExpressLRS/pull/1277

• Déjà Vu Diversity Aid (DVDA) - On top of FLRC, these modes use multiple sends to create more reliable connection when faced with interference such as at FPV races with many transmitters. 250Hz and 500Hz versions, which do quad and double sends respectively, and across multiple frequencies. https://github.com/ExpressLRS/ExpressLRS/pull/1527

• More Full Resolution channels (Full) - Instead of just 4ch + 8x switches, support for 10-bit 8ch/12ch/16ch modes in 100Hz and 333Hz rates, using LoRa modulation. https://github.com/ExpressLRS/ExpressLRS/pull/1572

• LBT - For compliance, listen-before-talk has been added to allow certification of our TX modules in the EU up to 100mW. https://github.com/ExpressLRS/ExpressLRS/pull/1243

• Increased precision over 2.x modes - 25% better stick precision in the 988us to 2012us range, except for fullres modes. 1 "bit" over-the-air used to represent 1.2us of stick, now 1 bit = 1us. https://github.com/ExpressLRS/ExpressLRS/pull/1572

• Video: ExpressLRS 3.0 Packet Modes Explained https://youtu.be/ymv9OJFWgJ4

New Features

• Wifi-based Betaflight Configurator through the RX (mobile and desktop versions). https://github.com/ExpressLRS/ExpressLRS/pull/1274
• Loan model - Easily loan your quad to someone else by effectively binding it to their TX from Lua or by bumping for TXes with accelerometers (Axis Thor). https://github.com/ExpressLRS/ExpressLRS/pull/1459 https://github.com/ExpressLRS/ExpressLRS/pull/1510
• Dynamic bind phrase - A loan not enough? Just type a new bind phrase in the web-ui to own the model forever.
• PWM servo output refactored - Allows per-output servo rate (50Hz, 100Hz, 160Hz, 333Hz, 400Hz) and massively reduced update latency over 2.x. https://github.com/ExpressLRS/ExpressLRS/pull/1558
• Lua config for receivers - Currently just telemetry power and diversity antenna select. https://github.com/ExpressLRS/ExpressLRS/pull/1362
• VBAT telemetry for PWM RXes - Not just the Matek converters, built into the native PWM RX itself.
• Lua shows TX Power / VTX Admin settings without drilling down. Current Model ID and Tlm bandwidth shown as well. https://github.com/ExpressLRS/ExpressLRS/pull/1436
• Updated web-ui with tabs and more options. https://github.com/ExpressLRS/ExpressLRS/pull/1604

Functionality changes

• Rewritten Dynamic Power - Uses SNR instead of RSSI to determine appropriate power, as RSSI doesn't factor in the noise floor or if the RX has an amplifier. Also reacts faster, needing just a single telemetry packet to make a decision, and preemptively steps up power when missing packets instead of waiting to jump to full. Also will lower power if overloading the RX at close range. https://github.com/ExpressLRS/ExpressLRS/pull/1529
• "Standard" telemetry ratio - Automatically picks a basic ratio for the selected packet rate, which means it will pick a “good default” for the packet rate selected. https://github.com/ExpressLRS/ExpressLRS/pull/1599
• "Race" telemetry ratio - Same as "Standard" except disables telemetry and SYNC packets when armed (replaces NO_SYNC_ON_ARM). https://github.com/ExpressLRS/ExpressLRS/pull/1599
• New (factory defaults) transmitter modules now default to 250Hz for Team2.4 #1815

Minor enhancements and fixes

• New Lua file name: elrsV3.lua (V3 LUA also works with 2.x firmware as well)
• Display warning message when baud too low for the selected RF mode https://github.com/ExpressLRS/ExpressLRS/pull/1672
• Long-press the button on receivers to reset RX config https://github.com/ExpressLRS/ExpressLRS/pull/1681
• Reduce handset sync margin - Reduces latency for all RF Modes by 0.3ms https://github.com/ExpressLRS/ExpressLRS/pull/1532
• Increased telemetry bandwidth - Makes things like RxBt and GPS position update more frequently.
• TX modules will not start transmitting until they receive a ReceiverID command from the handset, or at least 5s from the first received channels packet. This prevents syncing using ModelID 0 on boot #1775
• Lua: Update sensitivity while changing packet rate #1808
• Lua: Don't pause updating while in edit mode #1809
• Lua: Support touch events on popups, reduced code size #1753
• Safer updating of SwitchMode on the RX instead of ignoring it #1792
• Adjust VBAT scaling for 6ch PWM RX #1724
• Fix difficulty flashing Betaflight passthrough where target name was reporting a number #1708
• Allow TX to function with a failed accelerometer #1698

New targets

• TX12 Target #1738
• EMAX OLED TX and RX #1787
• Foxeer RX #1796
• HappyModel EP1 Dual RX #1821
• Unified ESP targets - Our internals are now set up to produce just one firmware image for all devices of the same type (all ESP32-based TXes, all ESP8285 RXes and now ESP32 based RXes) https://github.com/ExpressLRS/ExpressLRS/pull/1552
• Integrated VTX - New receivers with the VTX combined on a single MCU, similar to the Happymodel Fyujon, but without the extra MCU for the VTX side. This will allow for AIOs with serial RXes, rather than SPI, thanks to us taking over the VTX duties and only using a single UART. Keep an eye out for the next generation of ExpressLRS AIO’s from your favorite manufacturers in the near future. Manufacturers and DIYers can find reference designs here https://github.com/ExpressLRS/ExpressLRS/pull/1607
• True diversity receivers with optional integrated VTx - working with manufacturers currently to make these Manufacturers and DIYers can find reference designs here https://github.com/ExpressLRS/ExpressLRS/pull/1555#issuecomment-1146757077
• Receivers with more PWM outputs - working with manufacturers currently to make these, 6ch, 8ch and 10ch at least in pre-production
• Use any (ESP8285) receiver as TX - Just for DIYers really https://github.com/ExpressLRS/ExpressLRS/pull/1457

Known Issues

• On performing WiFi updates to some TX modules you may get a “Bad Size Given” error. If you get this error, it can be remedied by either flashing via UART, or flashing the repartitioner from https://github.com/pkendall64/repartitioner/releases/download/1.0/repartitioner.bin then reflashing via wifi after it has completed. For more information about the problem see https://github.com/pkendall64/repartitioner/