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Quick start Guide

Guide to get the 8MMNavQ up and running quickly

Getting started with your NavQ kit

The NavQ is a device that will allow you to add extra compute to your HoverGames drone system. With an i.MX 8M Mini processor, you will be able to reach new boundaries of vision and sensor data processing.

Current Demo build version

The current Demo build was built on 7/24/2020. Confirm you are on the correct image by running uname -a. You should get the following output:

Notice about SD Card Slot

The SD Card slot on the NavQ is sandwiched between the Media Board and the HoverGames Interposer Board. There are several important components underneath the SD card slot. We highly recommend that you be very careful when using the SD card slot so the components are not damaged. One notable component is the USB controller - it is quite small, so if it gets damaged, you won't be able to use USB devices over the MicroUSB port. One way to be safe when inserting or removing the SD card is by using some tweezers as seen in the image below.

Default username/password for the Demo image

The SD card included in the NavQ kit is preloaded with our HoverGames-Demo Linux distribution. The default username and password are:

Username: navq Password: navq

Powering the NavQ

To power your NavQ, there are two options. The first is to use one of the included USB-C cables and connect it to a USB port on your computer.

The other option is to power it through one of the included connectors in your NavQ kit. These connectors plug into the 5-pin POWER port next to the boot switches on your NavQ. You may use the barrel connectors or the XT60 power breakout connector. Some images and more details can be found here:

Accessing the serial console

To access the serial console on your NavQ, attach one of the included USB-C cables to the USB->UART adapter included in your kit. You can use programs such as PuTTY to access the serial console. A full guide to do this is linked below.

Expanding the SD card

When your board arrives, the Demo image will already be loaded to the SD card. This image does not take up the full amount of space on the SD card, so you'll need to expand the space in order to install more packages such as ROS or OpenCV. Follow the guide here to do so:

Mounting your NavQ to the HoverGames Drone

Follow the guide linked below to mount your NavQ to your drone:

Using your NavQ as a desktop computer

Depending on which Linux distribution is loaded, you may find that the NavQ includes a desktop application. This may be a minimal desktop with only a terminal emulator or it may be more feature rich like Liri Desktop.

Liri Desktop is not yet supported. Currently we only have a basic Wayland desktop with a terminal. You can run GUI applications through the terminal. Try installing firefox with apt and run it!

MIPI-DSI to HDMI adapter

The signaling is output on the MIPI-DSI port and if a compatible LCD panel is attached, then it would be visible there. Most of us will have access to a standard HDMI monitor, and there is a MIPI-DSI to HDMI adapter included in the kit also.

Connecting a mouse and keyboard

In order to connect both a mouse and keyboard to the NavQ you will need to connect the included microUSB to USB-A hub. Other USB peripherals may also be supported but need to be tested as it is not guaranteed that all USB drivers will be available.

Recording a video with NavQ

GStreamer

You can use GStreamer to take 1080p 30fps video. This uses the included H264 encoding plugin for i.MX 8M Mini. Here's an example pipeline you can run on your NavQ to take video:

When you want to end the video, just press Ctrl+C to cancel the pipeline, and the file should be saved to the present directory.

OpenCV

To record video with your NavQ, you can run this simple python script that uses OpenCV to write video to a file:

This is a simple example that you can use as a starting point for even bigger things with OpenCV/computer vision! If you'd like a more sophisticated guide that runs through example code to detect red objects, head to the to find more.

Controlling HoverGames drone with NavQ

To perform off-board control of the HoverGames drone from the NavQ, you'll need to get a little bit involved with ROS + MAVLink (MAVROS). To see a guide on how to get started, head over to the !

Connecting to WiFi

A package named connman is included in the image to help you connect to WiFi through the command line. To connect to WiFi, run the following commands:

When you run services, there may be duplicates of each WiFi network. Try to connect to your WiFi network with each key until it works. Sometimes the first one works, and sometimes the second one works. You will get a connection successful message if it works correctly.

Your NavQ should automatically connect to WiFi when rebooted. If you want to connect to another WiFi network, just go through the same process again.

Transferring files to and from NavQ over FTP

If you need to transfer files to and from the NavQ over a wired or wireless connection, you can use FileZilla to access the NavQ's FTP server. First, you'll want to connect the NavQ to your local network (WiFi or Ethernet) and run ifconfig to find the IP address that was assigned to your NavQ. Then, use FileZilla to connect to that IP with the username navq and password navq.

A guide on how to use FileZilla is here:

Next steps

Now that you've gone through the Quick Start Guide, you can move on to the Developer Guide if you'd like to go more in depth. Use the sidebar on this Gitbook to navigate to the next section.

Power input

Power input specification

The NavQ can take a voltage of 5V to 20V.

The board may also be powered via USB- which also has a 20V max input rating.

Note that while the voltage regulator on the external JST-JH power connector has absolute max rating is 26V. According to the schematics, there is a 20V TVS Diode (PTVS20VS1UR) at that input before the regulator (MP8759GD), with a breakdown voltage of 22.2V to 24.5V according to the datasheet.

Any experimentation above 20V input should take this into account and be done at your own risk.

Power input protection

There is some, but limited power input protection on board. Given this is typically for USB-C application, it may not be sufficient in harsh operating environments. You may want to provide some additional reverse polarity protection, over-current, or DC-DC conversion/isolation from the battery if you expect to be experimenting outside the HoverGames normal operating range or treating it harshly.

Battery supply protection

Please monitor your LiPo battery carefully for undervoltage conditions. If left connected, the NavQ and HoverGames drone will completely drain your LiPo battery and could cause permanent damage to your battery. There are no undervoltage disconnect provisions built in.

Low battery monitor

A simple solution to undervoltage protection may be to add a hobby grade low battery monitor alarm. These sound a loud alarm when any cell goes below a user set threshold voltage. The LED display will also show the individual cell voltage and total pack voltage. This plugs into the balance connector of the LiPo battery. They are inexpensive and available at hobby stores or online at typical outlets. Here are some examples:

Amazon - ""
Amazon - ""

Power Cables

Options and cables for powering the NavQ

NavQ Cables

The NavQ ships with several cables. They allow for several configurations when powering the NavQ

USB-C

When working on the bench you may wish to power the NavQ from USB-C input cable. This cable is provided. It would also be possible to power the NavQ while on a drone from a separate USB-C battery pack like those for Cell phone power.

Please note that some USB-C ports on charging adapters and particularly on unpowered Hubs may not supply enough current to run the NavQ and all the peripherals. If you notice a booting failure, please first try powering from an external battery or known high power USB-C charger or power supply.

Drone power cable supply

Downloading & Flashing the HoverGames-Demo Linux Image

Preparing the image

The HoverGames images come as a .bz2 compressed archive. To decompress this image, you'll need to use a program like 7zip on Windows, use the bunzip2 command on Linux, or double click the archive on Mac.

Flashing the image to eMMC or SD card using UUU

Downloading UUU

NXP has a tool for flashing i.MX hardware called UUU (Universal Update Utility). You can download UUU from here:

It is recommended to download the "Latest Release", not the "Pre-Release" at the top of the page.

If you're on Windows, you'll want to download the uuu.exe file, and if you're on Linux, you'll want to download the uuu file.

Downloading the Linux image

You must agree to all of the applicable licenses and agreements at the following link before downloading the Linux software. It is hosted here:

Downloading the bootloader

NOTE: This file is only needed for flashing with UUU to the eMMC/SD Card. If you want to flash your SD Card with dd or Win32DiskImager, this file is not needed.

Step 1

Flip the DIP switches on your NavQ to put it into USB flashing mode (boot from USB in the image below). Here is an image that shows how to do so:

Once you're done flashing, you can use this image to select the boot mode: eMMC or SD card.

Step 2

Connect your NavQ using the included USB-C cable to your computer. You should recieve a message on your computer that it has been connected. To make sure the NavQ is connected, you can run the UUU program with the -lsusb flag and you should see an output similar to this:

Step 3

You can flash both the SD card and the eMMC using this tool. The keyword for flashing the SD card is sd_all, while the keyword for flashing the eMMC is emmc_all. The command to flash your board is outlined below:

There are advantages and disadvantages to each storage medium. eMMC is faster, but is locked to 16GB size and is non-removable. SD cards can be of any size you like and are removable, but they are quite a bit slower.

After a few moments, your board should be flashed. Unplug your NavQ from power, reset the DIP switches to the desired boot device, and you're good to go!

Flashing the image to SD card using dd or Win32DiskImager

To flash the image, you'll need to use dd on Linux/Mac or Win32DiskImager on Windows.

Linux

Replace the X in "/dev/sdX" with the letter of your SD card in linux. You can use a program like "GParted" or "Disks" to find the letter of your SD card.

Mac

Replace the X in "/dev/rdiskX" with the number of your SD card in Mac. You can use diskutil list to find the number of your SD Card.

Windows

Download Win32DiskImager:

Currently the HoverGames-Demo Linux image is packaged as a .img file. In future releases, it may be packaged as a .wic.bz2 file. If it is packaged as a .wic.bz2 file, you'll want to extract the .bz2 file before flashing using Win32DiskImager.

Open the program and select your SD card. Choose the .wic OR .img file, then click "Write".

Expand space on SD card/eMMC

Easy-to-use script

We have created an easy-to-use script to resize the flashed image on your device. Since the image is smaller than the storage device, it is not properly expanded when first flashed. You can run the following script to expand the filesystem.

This script should be in the home folder of the demo image. If it isn't there, or if you lost it and need it, it is linked below.

To run the script, run the following commands for the boot device you're currently using:

For eMMC:

For SD card:

Making the script executable

The script should be executable when it is included in the image. If it isn't, then you'll need to make it executable by running the following command:

Manually expanding space

If you don't want to use the script, you can run the commands below.

You may run into an issue where you run out of space on the eMMC or SD card when installing ROS. To expand the rootfs partition, follow these steps:

If you're on the eMMC, you'll use /dev/mmcblk2. If you're on an SD card, use /dev/mmcblk1. By default the NavQ boots from the included SD card in your kit.

Once you're done with those steps, run this command:

and reboot. You should now be able to install ROS Melodic without size issues.

Commands for fdisk

If you prefer to just see the commands, these are the commands you need to run in fdisk in order to resize your disk.

Serial root console

Connecting to the root console on NavQ using the USB--UART adapter

The root console will allow monitoring of the board from initial boot. Since modern PCs don't tend to include serial ports anymore, a small FTDI USB-UART adapter is provided to convert the serial port to USB.

Hardware connection

Plug the 6 pin JST-GH cable from the USB-UART converter into NavQ connector "UART2/I2C2"
Plug the USB-UART into your pc like you would a dongle or memory stick
- Your PC operating system should respond right away when it recognizes the USB-UART. On windows it will play a "usb connect sound"
- There should be a red light illuminated on the USB-UART board (even when not plugged into the NAvQ)
Follow the terminal configuration below and power on the NavQ

Troubleshooting Tip: If the COM port does not show in Device Manager or you don't hear the "usb connect sound" double check that the USB-C connector is fully plugged in and seated into the USB-UART adapter board.

Troubleshooting Tip: If the USB UART is not detected on your PC, in some instances you may need to download FDTI USB-UART driver software. It can be found here:

Terminal software connection

A terminal program will be required to communicate over the serial console. The following example is for a Windows 10 PC using the terminal program .

Default NavQ terminal settings are: 115200 Baud, N, 8, 1 (no Parity, no flow control)

In Windows 10 use Device manager to determine which COM port is assigned to the FTDI USB-UART serial adapter. The open PuTTY window shown below is the root console of the NavQ.

Configuring PuTTY

There are several options for a terminal program that can be used. This example is for PuTTY on a Windows PC. Other programs and other hosts can be used. Example using PuTTY to connect to the serial console via a USB-UART adapter. In this example the COM port was determined above by looking at Windows 10 Device manager.

Mounting NavQ on HoverGames Drone

How to mount the NavQ using the plate and standoffs provided

The suggested method of mounting the NavQ to the Drone frame is shown below. Improvements and suggestions are welcomed. Please message on community.nxp.com here: https://community.nxp.com/community/mobilerobotics/hovergames-drone-challenge

Use two of the Hex standoffs together to make ~35mm total standoff height between the top plate and the NavQ mounting plate

The NavQ can mount to the small carbon fiber plate using screws, standoffs or double sided tape.

We did allow for mounting the NavQ with screws, HOWEVER one of the three mounting holes did not get drilled. Please drill the third hole by hand if you wish to mount with screws. Alternatively you can use two screws and some double sided tape for the missing screws. You should use tape or a 3rd hole, because otherwise the board will vibrate too much.

Note the use of short hex standoffs instead of nuts under the main top-plate because they are easier to hold with needle nose pliers without needing to disassembe the complete frame.

One modification tried was to add a second standoff "hanging" from the front so that the camera module could stick between these two front standoffs to with double sided tape.