# MR-VMU-Tropic overview

The MR-VMU-Tropic is the flight-controller (vehicle management unit) reference design of the NXP
Mobile Robotics family. It is a PX4 / NuttX autopilot built around an NXP i.MX RT1064 crossover
MCU, providing the real-time flight-control and I/O functions of a drone or mobile robot. The board
is intended as a validated flight-controller starting point that customers can evaluate, reproduce,
and adapt for their own vehicles.

The i.MX RT1064 is an NXP crossover MCU based on an Arm Cortex-M7 core with integrated flash and
on-chip real-time clock. It runs the PX4 flight stack on the NuttX RTOS and drives the motor
outputs, sensor interfaces, and communication links required for autonomous flight and motion
control.

## Functional block diagram

  

```{image} resources/mr-vmu-tropic-block-diagram.svg
:alt: MR-VMU-Tropic functional block diagram
:width: 840px
:align: center
```



Figure 1. MR-VMU-Tropic functional block diagram

## Main components

The reference design integrates the following main NXP components and interfaces:

- i.MX RT1064 crossover MCU (Arm Cortex-M7) with internal RTC
- 3.3 V regulation from a 9 V to 52 V input through the NXP PM02DHV power module
- Redundant inertial sensors, magnetometer, and a Bosch BMP390 or BMP388 barometer
- CAN-FD / DroneCAN through the NXP TJA1462 transceiver
- 100BASE-T1 automotive Ethernet through the NXP TJA1103 PHY
- UART telemetry, GPS / safety, and RC / ELRS inputs
- RC-PWM / DShot motor outputs and SPI OSD expansion
- USB-C console and SWD / JTAG debug through the Dronecode debug connector

NXP also provides the complete hardware Bill of Materials and design files, enabling customers to
evaluate, reproduce, and customize the reference platform for their own products.

For overview information, documentation, software, tools, and ordering details, see the
[MR-VMU-Tropic product page](https://www.nxp.com/design/design-center/development-boards-and-designs/MR-VMU-TROPIC)
on the NXP web site.

> Note: The barometric pressure sensor is either a Bosch BMP390 or a Bosch BMP388, depending on
> component availability at manufacturing time. The BMP388 is a drop-in, functionally equivalent
> replacement for the BMP390; the two parts differ only in minor specifications that do not affect
> the flight-controller use case. The software supports both sensors, so no user action is required
> regardless of which part is fitted.