ARK Electronics recently showcased the ARKV6X-RT, an NDAA-compliant flight controller based on the FMUV6X-RT and Pixhawk Autopilot Bus open standards. The module uses an NXP i.MX RT1176 microcontroller and includes three synchronized IMUs, onboard FRAM, a secure element and PX4 Autopilot support.

For context, the i.MX RT1176 integrates a 1GHz Arm Cortex-M7 core and a 400MHz Cortex-M4 core, along with 2MB of RAM. PX4 documentation notes that the Cortex-M4 core is currently unused by PX4.

The controller has no internal flash for code storage and instead executes from a 64MB external octal NOR device connected over FlexSPI1, with PX4 using the first 4MB. The flight controller also includes an NXP EdgeLock SE051 secure element and FM25V02A FRAM for parameter storage.

ARKV6X-RT Flight Controller bottom view

The sensor suite consists of three IMUs on separate SPI buses: an InvenSense ICM-45686, an InvenSense IIM-20670 and an ST LSM6DSV80X. The board also includes a Bosch BMP390 barometer and an ST IIS2MDC magnetometer.

Each IMU has its own power rail and data-ready line. PX4 lists the ICM-45686 as the primary sensor, while the IIM-20670 is used as a navigation and fallback IMU. The LSM6DSV80X publishes its ±16g accelerometer channel, while its ±80g high-g element is not used.

ARKV6X-RT Flight Controller top view

A 1W heater is provided for sensor temperature control in cold environments. PX4 documentation states that the heater operates in closed loop using the ICM-45686 die temperature.

The ARKV6X-RT follows the Pixhawk Autopilot Bus form factor and requires a compatible carrier board. Physical ports and outputs therefore depend on the selected carrier. The module provides 12 FMU PWM outputs, with eight additional outputs available through PX4IO on carriers that include it.

ARK Pixhawk Autopilot Bus Carrier bottom view

Other interfaces include eight serial ports, four I2C buses, four SPI buses, two CAN buses enabled by default, 100BASE-T Ethernet, USB and RC input. The PAB standard also provides pins for a third CAN bus, although ARK notes that its current carrier boards do not expose it.

The module includes a microSD slot and supports two digital power bricks using INA226 devices by default. INA228 and INA238 drivers are also included for compatible carrier boards.

ARK Pixhawk Autopilot Bus Carrier top view

ARK’s own PAB carrier provides dual power inputs, 100Mbps Ethernet, dual CAN, GPS and telemetry ports, eight PWM outputs, UART/I2C, SPI, RC interfaces, USB-C and a debug connector.

PX4 Autopilot ships by default on the ARKV6X-RT, with the ark_fmu-v6xrt_default firmware target and PX4 documentation covering build, upload and recovery procedures for boards without a bootloader or with erased external NOR flash.

Specifications listed for the ARKV6X-RT include:

• Processor:
  • NXP i.MX RT1176
  • Arm Cortex-M7 at up to 1GHz
  • Arm Cortex-M4 at up to 400MHz
  • 2MB RAM
• Storage:
  • 64MB external octal NOR flash
  • FRAM parameter storage
  • 1x microSD card slot
• Security:
  • NXP EdgeLock SE051 secure element
• Sensors:
  • InvenSense ICM-45686 IMU
  • InvenSense IIM-20670 IMU
  • ST LSM6DSV80X IMU
  • Bosch BMP390 barometer
  • ST IIS2MDC magnetometer
• I/O:
  • 12x FMU PWM outputs
  • Up to 8 additional PX4IO outputs on supported carriers
  • 8x serial ports
  • 4x I2C buses, 4x SPI buses
  • 2x CAN enabled by default
  • 100BASE-T Ethernet
  • USB
  • RC input
• Other:
  • 1W sensor heater
  • LED indicators
• Power:
  • 5V
  • 500mA total
  • 300mA main system
  • 200mA heater
• Mechanical:
  • 36 × 29 × 5mm (SoM)
  • 5g (SoM)
  • 74 × 43.5 × 12mm (Carrier board)
  • 22g (Carrier board)

Further Information

The ARKV6X-RT product page is already available, although ARK Electronics has not published pricing information.