NEXUS-XR Helicopter Flight Controller ROTORFLIGHT 2.2 ELRS RadioMaster

The NEXUS-XR Helicopter Flight Controller from RadioMaster is the extended version of the NEXUS-X with integrated 2.4GHz ELRS receiver and optimized for ROTORFLIGHT 2.2. It combines high compatibility, performance and ease of use in a compact design. With the powerful STM32F722-MCU and the precise ICM42688P 6-axis MEMS motion tracker, it offers exact control and stable stabilization – perfect for RC helicopters from 250 to 700 sizes. After over 12 months of intensive development and testing by Rotorflight developers and beta pilots, the NEXUS-XR is the ultimate all-in-one FBL controller for wireless ELRS integration and maximum range. 3 5

Precise control and low latency with ELRS

The NEXUS-XR is based on the proven rotorflight design and optimizes flight stability through advanced gyro technology. The ICM42688P tracker offers excellent vibration resistance and signal filtering, ideal for electric and nitro helicopters. With Dual-Semtech SX1281 2.4GHz transceivers and two 65mm wire antennas, the integrated ELRS receiver ensures superior signal strength and range – without separate receiver. Support for PWM, Oneshot, Multishot and DShot as well as Tail-ESC servos (760μs/1520μs) and Tail motors ensures reactive handling without delays – whether for freestyle or 3D acrobatics. 3 5

Diverse receiver compatibility and telemetry

The controller supports CRSF, ELRS, GHOST, S.BUS, SUMD, IBUS, XBUS, EXBUS, PPM and MSP – ideal with EdgeTX and the integrated ELRS. The extended telemetry (S.BUS, HoTT, S.Port, MSP, EdgeTX, ELRS) allows real-time monitoring while the RPM sensor (from the ESC) measures precise speeds. The improved BEC delivers stable power supply, and the external voltage input (3.6-70V) makes it flexible for demanding setups. 6

Integrated black box and security

With 256 MB of flash memory (W25N02KVZEIR), the NEXUS-XR logs all flights for detailed analysis and fine-tuning. The standard functionRotorflight Rescue ensures safe landings in emergencies. The CNC-milled aluminum housing protects the electronics and serves as a heat sink to keep temperatures low under load. Additional PWM pins allow extended control in complex builds. 3

Compact design for all builds

With dimensions of 41.3 mm x 25.4 mm x 13.1 mm and a weight of only 16.8 g, the NEXUS-XR fits seamlessly in small and large helicopters. Optional housing colors (gray, gold, red, blue, purple) allow personalized design. The power supply ranges from 5-12.6 V, with 5 V/2.0 A output at the serial ports and 3.3 V/0.5 A for DSM. 0

HIGHLIGHTS OF THE NEW NEXUS-XR

• Integrated ExpressLRS receiver: Two Semtech SX1281 2.4GHz transceivers for seamless HF performance, eliminating the need for an external receiver.
• Optimized for Rotorflight 2.2: Designed for peak performance and compatibility.
• Precision control: STM32F722 MCU and ICM42688P 6-axis gyroscope/acceleration sensor for superior flight dynamics.
• Flight logging: 256 MB of built-in flash memory for detailed logging and fine-tuning.
• Dual antenna design: Two 65mm wired antennas for excellent signal strength and range.
• Versatile connectivity: Multiple UART ports support CRSF, ELRS, S.BUS and more.
• More PWM pins: Additional pins for advanced control in complex setups.
• CNC-machined aluminum housing: The slim, robust design also serves as a heat sink for cooling the system.
• Rear servo/ESC support: Compatible with 760 μs/1520 μs rear servos and ESCs.
• 12V servo support: Supports 12-volt servos.
• Wide voltage range: Supports external power supply from 3.6V to 70V for flexible configurations.
• Improved BEC: Stable, reliable power supply of electronics for improved performance.
• Isolated power supply: Own 1.8V (gyro), 3.3V (MCU) and 5V (interfaces) power supply for noise minimization.
• USB-C Port: Lightweight, flexible USB-C extension cable for easy access in tight designs.
• Compact and lightweight: Ideal for all helicopter models.
• Rotor flight rescue: standard function for more safety in an emergency.
• Optional housing color: Grey / Gold / Red / Blue / Purple.

Technical data

• Article: Nexus-XR Helicopter Flight Control
• Firmware: Rotorflight 2.2
• MCU: STM32F722RET6
• Gyro (IMU): ICM42688P
• Flash memory (Black Box IC): 256 MB (W25N02KVZEIR)
• Barometer: SPL06-001
• UART: 5 – S.BUS[UART1], TELEM[UART2], PORT-A[UART4], PORT-B[UART6], PORT-C[UART3]
• Servo: S1, S2, S3, rear servos (up to 12 V)
• Speed sensor: 1 – FROM ESC frequency sensor
• AUX: 1
• External voltage input (Telephoto): 3.6–70 V
• Recipient support: CRSF, ELRS, GHOST, S.BUS, SUMD, IBUS, XBUS, EXBUS, PPM MSP
• Power supply (DC): 5–16 V
• Output power of the serial A-B-C interface: 5 V – 1.5 A
• Telemetry: S.BUS, HoTT, S.Port, MSP, EDGETX, ELRS
• Controls: PWM, Oneshot, Multishot, Dshot
• Rear control: 760 μs / 1520 μs
• Servo rear motor: Yes
• Internal Receiver: RP4TD-M ExpressLRS 2.4 GHz Mini True Diversity Receiver
• MCU: ESP32
• Type: ISM
• HF chip: SX1281 x 2
• Antenna: 65 mm 2.4 GHz wire antenna x 2
• Frequency range: 2.4 GHz
• Maximum refresh rate: 500 Hz / F1000 Hz
• Telemetry HF power: Max. 2 x 10 mW
• WLAN updates: Yes
• Firmware target: RadioMaster RP4TD-M 2400 RX
• Bus interface: CRSF
• Dimensions: 44.70 x 26.50 x 14.30 mm
• Weight: 24.1g

Advantages for RC helicopter pilots

The NEXUS-XR combines RadioMaster’s hardware quality with Rotorflight’s powerful open source firmware and integrated ELRS for unique precision, range and adaptability. Whether for beginners or professionals: It minimizes vibrations, maximizes stability and integrates safety features such as Rescue mode. Perfect for challenging 3D flights or relaxed exercises – and compatible with EdgeTX for seamless channel integration. 1 7

The Nexus-XR revolutionizes helicopter flight control by integrating a state-of-the-art ExpressLRS receiver with two Semtech SX1281 2.4 GHz transceivers. This integrated receiver offers exceptional RF performance, high range, reliability and effortless setup. External receivers are no longer needed, which simplifies the installation and reduces the weight.

The heart of the Nexus XR is the powerful STM32F722 MCU, paired with the 6-axis MEMS motion sensor ICM42688P. This sensor offers excellent vibration resistance and improved signal suppression, making it ideal for electric and nitro helicopters.

The Nexus XR has several important improvements. An improved BEC ensures a more stable power supply to the electronics and thus increases reliability. The external voltage input now supports a range of 3.6 V to 70 V. The memory has been expanded to 256 MB, which allows longer flight protocols. The CNC-molded aluminum housing is slimmer, but still serves as a shield and heat sink and keeps the system cool even during intense flights.

The compact, robust construction of the Nexus-XR is designed for maximum comfort. It fits a variety of helicopter sizes and offers peak performance under demanding conditions.

 

 

NEXUS-X/XR with INAV 9.x as Fixed Wing Flight Controller

For a while there has been an INAV target for the Nexus-X and Nexus-XR to use them in airplanes.

The Nexus-X and Nexus-XR are flashed with INAV 9.x also complete Fixed Wing Flight Controller with integrated dual-channel ELRS RX (model NEXUS-XR).

• Out of box, 8 servos and 3 UARTs are available. Plus an ESC port for the power supply or Engine. 9x PWM available
• Alternatively, 4 of the servo ports can also be configured to 2 UARTs (each 2 ports for TX/RX). So e.g. then 6 servos and 4 UARTs.

With the current INAV Configurator you can flash the NEXUS-XR directly: press FC boot button, connect via USB, then DFU must be written at the top right instead of a com port. Then select the NEXUS at Firmware-Flasher, activate «Full chip erase» and perform online download below and then start flashing

• Nexus-X/XR are flight controls, originally designed for helicopters with rotorflight. Based on the STM32F722RET6. NEXUS X and XR use the same target in iNav.
• Both models Nexus-X and Nexus-XR have an IMU type ICM42688P, a barometer type SPL06 and a blackbox memory chip type W25N02KVZEIR.

The NEXUS XR also contains a serial ELRS receiver based on the RP4TD-M with ESP32 and two SX1281. This is connected to the main flight control STM32F7 via UART5. All external connections are directly connected to the STM32F7 flight control. The receiver can be deactivated via USER1, which controls a pin to PC8.

The RPM, TLM, AUX and SBUS pins are standard servo/motor outputs. However, if UART1 or UART2 is assigned a function in the «Ports» tab, the pins become a UART instead. The pin assignment is from left to right when you look at the plug on the flight controller. Note that the pin assignment for «A», «B» and «C» on the Radiomaster website is incorrect; there RX and TX are swapped.

 

Delivery contents

• 1 * NEXUS-XR Helicopter Flight Control
• 3 * JST-GH 4-wire pigtail cable
• 1 * JST-GH to servo plug (3-pin Dupont plug)
• 1 * Ultra-light and flexible USB-C extender
• 1 * Type-C Extension Cable
• 1 * JST-ZH1.5 «DSM» telemetry cable (telemetry only, does not support DSM receivers)
• 1 * Voltage telemetry cable
• 3 * 3M double-sided mounting tape
• 2 * Shrink Tubing
• 1 * Inventory card