This section will track the changes over time of the PX4 software support for MR-VMU-RT1176

QGC

You should be able to flash PX4 via QGC. This long term is the preferred method when it works

• Flashing "main" works (03/05/2025)

• Flashing "beta" currently fails. (03/05/2025)

PX4 Git Status 03/05/2024

• Backport of PX4 1.14 Stable is in validation now. This was a backport from main. There are a couple of open issues still

• PX4 1.15 is in pre-release, VMU-RT1176 is included. This is a forward port of main, it has the most tested time on it.

Last build of PX4 Main

This link it to the last / latest version of PX4 Main is here. This is the working version.

DRAFT DRAFT DRAFT

Interim instructions - during board bringup and development 7/2022

Temporary image location (NXP INTERNAL ONLY)

Link to internal NXP Sharepoint for development images (TEMPORARY ONLY) Note external parties will NOT be able to access this link.

Temporaray image location (Externally shared)

These images are externally shared for specific developers. They are incomplete. They will be updated occasionally when requested by external parties and may not match the latest code. DO NOT RELY on this code in any way.

i.MX RT based vehicle controller

RT1176

Draft documentation related to MR-VMU-RT1176 AKA, MR-FMURT7, FMURT7, FMURT, VMURT7, VMURT1176, FMU-RT117x FMU-RT1176, FMU-RT1172.

The above mentioned boards are all either the same board with different naming conventions, or fully compatible boards. This design is fully compatible with other variants of i.MX RT117x such as RT1172 for production cost savings. The RT1176 has features that are currently unused, it is however more ubiquitous and easier to procure.

RT1060

There is also an original older design that was done useing i.MX RT1062 as well. The detail of this was not published, but there could be mention of it in this gitbook for specific reasons. That board was a precursor to the RT1176 design. Since that time, and now that code (particularly NuttX and drivers) are stable, there is a low cost opensource design called TROPIC that can also run PX4 and Cognipilot. You can find links to that on a page at the end of this document.

Naming Background

This design was based on the Linux foundation DroneCode PX4 FMU V6x reference design. However the "Flight Management Unit" (FMU) is suitable for more than just flying vehicles, therefore we are preferring to refer to it as a VMU "Vehicle Management Unit".

The VMU nomenclature s more generic, and in particular applicable to AMRs and other robotics applications such as MR-Buggy3, MR-B3RB-M, or rovers.

PX4/NuttX Naming

In PX4 the software target currently is referred to as FMU-RT117x (possibly FMURT7 for short)

(This needs to be checked an updated regularly - 7/12/2023 Iain)

FMU SOM module naming

Technically FMU-RT7 or FMU-RT1172 name refers to the pluggable module (SOM - system on module)

Vxx carrier board naming

Also note that Vxx or Vxx7 refers to the carrier board that the actual VMU module plugs into . It is important to note that NXP version of this carrier board includes T1 Automotive Ethernet and a 3rd CAN port. The Vxx7 version of the carrier board also removes the IO processor that was on the baseboard and not used. Instead there are EXTRA PWM signals on the latest PAB standard bus which are generated and come directly from the RT1176 chip.

VMU-RT117x complete assembly naming

The combined FMU-RT7/FMURT1176 + Vxx board we will refer to as VMU-RT117x (or possibly VMURT7 for short).

At this point time (11/11/2024) CAN3 is not enabled to use DronCAN or UAVCAN by default in PX4. The port itself is enabled and can be exercised using CANSEND and CANDUMP commands This tutorial describes how to enable the CAN3 Port on the NXP-VMU-RT117x in PX4-Autopilot, and demonstrates the transmission of CAN Frames between two VMU-RT117x using the can-utils module.

ITEMS REQUIRED

HARDWARE SETUP

The high level overview here is that we want to be able to both program and gain console access to the MR-VMU-RT1176 so we can issue commands. Note that there are other valid ways to get a console, such as through an attached Telemetry radio. Programming may also use MCU-LINK-MR.

SOFTWARE SETUP

PX4-Autopilot SETUP

Select the following options:

1. Device Drivers → CAN Driver Support

2. License Setup → Use components that have GPL/LGPL licenses

3. Application Configuration → CAN Utilities → SocketCAN cansend tool

FLASH PX4-Autopilot on VMU

Open a new shell and perform the following steps for flashing PX4-Autopilot on VMU-RT117x.

EXECUTION STEPS

Get the serial shell of the two VMU-RT117x on your host machine.

Execute "candump can2" on one shell and "cansend can2 123#1234567890" on the other.

DRAFT DRAFT DRAFT How to program the VMU using a JLINK (JLINK - loadfile or loadbin but start at address 0x30000000)

Interim instructions

Official instructions will eventually be on the PX4.io website and Cognipilot website. These are interim instructions for pre-production boards.

This is related to the pre-production units or units manufactured from a BLANK RT1176 chip.

Overview on Fuses

A BLANK chip will not have any fuses burned. This means it will default to only an internal on chip boot rom. We need to set the fuses so that by default it will boot from the flash memory.

Install NXP MCUXpresso secure provisioning tool

https://www.nxp.com/design/software/development-software/mcuxpresso-software-andtools-/mcuxpresso-secure-provisioning-tool:MCUXPRESSO-SECURE-PROVISIONING#downloads

(the for the provisioning tool can be found at the link above. This is the abbreviated version for RT1176 and the specific tasks for VMU-RT1176 board.)

Get Started

• Run the secure provisioning tool

• Select MIMXRT1176

• Click the create button

• Select OTP configuration (One time programmable)

• Press Yes, Wait for the script to finish. You should see a screen like this.

• Select "0x960" Fuse 0x960 as shown below:

• For the Bit-field BT_FUSE_SEL change to the required value = 1

Advanced mode for script generation

We will use Advanced mode in order to create a command line script that will program the fuses. It may be used to program subsequent VMU-RT1176 fuses

• Bottom-left corner and select advanced mode

• Press close

• Press generate script

{workspace} is C \ users \ $username \ secure provisioning

There you will find a file burn_user_OTP_cfg_win.bat

You can now use this file to burn fuses for any new boards with blank chips..

Flashing guide

This guide will briefly go through how to flash your RT7 board. To connect to the RT7 board the first step is to flash the board with the latest firmware. This is done in a few quick steps:

• Create an empty folder, then clone the PX4-Autopilot directory in it.

• Move to that new directory.

• Make the required RT7 binary file.

Connecting the adapter boards

After you have the binary set and ready you can connect the JLink adapter to the RT7 board (J23 port) through the Holybro Pixhawk debug adapter. The diagram bellow displays how these adapters should be connected to each other.

Holybro Pixhawk Debug Adapter

This adapter is used to connect the JLink to the RT7 board. You can also use the Serial port (USB-C) to debug the board and read and write messages in the board. A simple diagram of what each port in the adapter board is can be seen below.

Flashing the binary

After the adapter boards are connected to your PC and to the RT7 we can flash the board. You will need to install the SEGGER JLink probe to be able to use the adapter. This can be done by going through the installation instructions on the following PX4 page (just the installation is necessary):

Then you can launch the probe then follow the next steps when connected to the JLink.

1. Lauch the probe: JLinkExe

2. Type connect

3. Select SWD and target is

Now the board should be flashed with the latest firmware.

Update 10/26/2023 Dear Pixhawk 6X-RT testers (all on Bcc),

This change notice is due to the change of the PX4 build target name of 6X-RT to its final name px4_fmu-v6xrt

Steps to update

Within your PX4-Autopilot git directory do the following

1. git checkout pr-px4_fmu-v6rt

2. git pull –recurse-submodules

3. Connect the Pixhawk 6X-RT FMU via USB to your PC

PX4 Autopilot PR reporting

All important information / issues will be reported on the related PR -

We kindly ask you to report any issues found yourself on PX4 git with an issue report! Please tag in this case

Flight log reporting

With any flight testing please always upload your logs to

1. enable “Allow this log file to be used for statistical analysis”

2. upload the ogfile to

3. upload the LINK to the logfile to PR 22263 -

Thank you!

The NXP reference board design production version units have a slightly different connector set than what has tradionally been included in the standard V6X design and also the Holybro V6X-RT units. The key differentiators are: - No separate IO processor required. All PWMs including redundant coming from RT1176

• Three CAN ports

• 100BaseT1 two wire ethernet

• Additional SE05x secure element on the base board in addition to the FMUMRT1176

  • NFC antenna interface to secure element

• DSM and AUX RC ports in addition to "RC IN"

Right side interfaces

They include:

• AD@I/0 Analog and GPIO

• CAN1, CAN2: Dual CAN-FD interfaces employing CAN-SIC (Signal Improvement) CAN phys.

• I2C interface

Left Side Connections

• CAN3: (extra additional ) CAN-FD interfaces employing CAN-SIC (Signal Improvement) CAN phys.

• T1-ETH: 100BaseT1 Two wire 100MBPS Ethernet

• TELEM1/2/3: 3x Telemetry ports with Hardware handshaking

Front side connectors

• DSM: DSM RC radio input

• NFC: NFC connection to carrier board Secure Element. (interface may be accessible even when not powered?)

• GPS1: PX4 full GPS connector including Arming Button interface, beeper, magnetometer and RGB LED

PWM and SBUS IBUS RC input

Typical connection for SBUS/IBUS input from RC remote controller. (note: Alternative RC interfaces possible)

Debugger and serial console connection

Use Cognipilot Neural probe or DCD-LZ-ADAPT or similar adapter to connect a debugger or serial console to the Pixhawk-debug-full port (AKA DCD-F)

Indicator LEDs

Note the legend for the LEDs is actually shown above the 4 led holes in the enclosure.

ASEL analog input select indicator

Schematic showing alternative function. D5 = ASEL LED. J14 pin 7 'ADC1_6v6_Aux', can be selected to connect either 'ADC1_6v6' or Vdd Servo rail to the ADC to read the voltage.

These instructions will not be very detailed, as most steps are already explained elsewhere in other GitBooks. Note: Links will be provided in each step to those pages.

Controlling an RC rover with the RT7 can be done in a few steps. These steps are divided into:

1. Loading the firmware

2. Connect necessary components

3. Link QGroundControl to the board

4. Link controller to the board

5. Set and tweak parameters

Loading the firmware:

First step is to download the latest firmware and bootloader then flash it to the RT7 board. This step is explained in the .

Connecting components:

Then make sure to place the desired components to the rover, then connect them to the board. In this example the radio transmitter, Motors and ESC, telemetry radio and battery are required. Below is a list where each module should be connected:

View the page to have a reference to where each port is.

QGC to RT7 board:

This step should be quite simple, as long as you have QGC installed, and the Telemetry antennas are connected to your PC. The program should link to the board automatically. If it does not connect automatically go to the Application Settings, then check if you have AutoConnect enabled for the devices you are using.

RC controller to RT7:

To connect the RC controller to the RT7 board you must connect the transceiver to the board through the designated port (J15). Once connected and you have provided power to the board, turn the controller on, then go to Settings>>System and click on RX bind. When both the controller and transceiver are bonded you can open QGC to setup and map the controls to the rover.

Setting parameters:

A few more steps are required for full setup. Follow in the NXP CUP GitBook for those instructions.

After completing all these steps your rover should follow your commands on the RC controller. In case there are any issues try going through other GitBooks related to this example ( & ).

Top view

Back view

Left side view

Front view

Right side view

xxxDRAFT DRAFT DRAFT

Q: Is this the correct connection for drone motor connectors?

I read the connectors file that you send to me. I think it is a mismatch between FMU -main PWM out and I/O – AUX PWM out. In the firs picture from the attachment, you can see how I connected the inputs for motors’ PWM. It was the only position on which I was able to check them from QGroundControl (the spin direction and motor position).

Burning fuses on X-MR-VMU-TROPIC

Note some screenshots are based on IMXRT1176 guide, but process is quite similar

Install NXP Mcuxpresso secure provisioning

https://www.nxp.com/design/software/development-software/mcuxpresso-software-and-tools-/mcuxpresso-secure-provisioning-tool:MCUXPRESSO-SECURE-PROVISIONING#downloads

Start secure provisioning

Select MIMXRT1064

Select create

Select OTP configuration

Press Yes

Wait for the script to finish

Select "BOOT_CFG1"

Fuse BOOT_CFG1

BT_FUSE_SEL select Required value 1 Bottom-left corner and select advanced mode

Press close

Press generate script

{workspace} is C \ users \ $username \ secure provisioning

There's a burn_user_OTP_cfg_win.bat

You can use to burn fuses for new boards

If you will be using PX4 software with the MR-VMU-RT1176 board then you will need to first program the bootloader if not already installed.

The abbreviated instructions are as follows:

TROPIC Community

• Uses Teensy 4.1 Design files on github

• Rev B has Ethernet not working

• Rev C Planned

• Doc repo (currently private)

X-MR-VMU-TROPIC

• Design files on request - may be on github

• POC board only

• Rev D is current.

• Chip down design