Jetson Nano USB Login

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In this article I'm going to show you how to connect and login to an NVIDIA Jetson Nano using a special USB serial cable. You won't need a monitor, keyboard, or mouse - except during the initial setup, which I will explain next.


Step 1 - Setup a Nano for the first time

If you've already gone through the Jetson Nano setup process and have username and password you can skip to the next step.

Currently there is no lite version of the official Nano disk image. You can't boot it for the first time over USB and create a user name and password. You have to wire it up to a monitor, keyboard and mouse. Then use their desktop GUI to accept their terms and create and setup a login.

Download the Nano SD card image

You can download the official Jetson Nano image here:

Flash the image to the SD card

You can flash the image to the SD card using Etcher.

I recommend using at least a 64GB card, such as this one:

Set username and password

Once the image has been flashed to the SD card, remove the mini SD card from the adapter and plug it into the Nano. Power it up and setup your login info.

Once you are done, you can disconnect all the peripherals. Then wire the Nano to nothing but a power supply and a special USB cable, which I will explain how to do in the next step.

Mini Keyboard and Touchpad

If you need a portable keyboard and touchpad, this handy little device can fit in a large pocket or backpack. I've used an older version to setup a Nano. To use it, you pull the USB connector out of the side and plug it into the Nano. Then all you need is an HDMI monitor and a power supply:

Rii Mini Wireless 2.4GHz Keyboard with Mouse Touchpad Remote Control, Black (mini X1)

What about the JetBot image?

I tried using the JetBot image to avoid requiring a monitor and keyboard for the initial setup. It didn't work for me.

Step 2 - USB to TTL Serial Cable

To connect your laptop to the Nano, you need a USB-to-TTL Serial Cable. This is a cable that I use to connect to a Raspberry Pi. It also works with the Nano. You can find it here:

Step 3 - Setup the USB Serial Cable Driver

To use the serial cable you need to install drivers. You can find information for your operating system here:

Mac Driver Instructions

Here are the instructions for testing the cable using a Mac:

  • Plug the USB device into your Mac (we will worry about plugging it into the Nano later)
  • Open up a Terminal window
  • Run this command: ls -ls /dev/cu.*
  • You should see a listing like this: /dev/cu.usbserial
  • Unplug the USB Serial Cable from your Mac
  • Run this command (again): ls -ls /dev/cu.*
  • The device should no longer be listed

Step 4 - Wire the USB Serial Cable to the Nano

To the left of the heatsink on the Nano you will see a strip of 6 pins.

From the outer edge of the board inward those pins are:

  • CTS - Clear to Send
  • TXD - Transmit (White Wire (RX) -> TXD)
  • RXD - Receive (Green Wire (TX) -> RXD)
  • NC - Not Connected
  • RTS - Request to Send
  • GND - Ground (Black Wire (GND) -> GND)

You can confirm which pin is which by flipping over the Nano and looking at the labels listed on the board.

I've also included in the list above which color wire from the USB Serial Cable should be connected to which pin.

The red wire from the cable does not connect to anything.

Wire the USB Serial cable to the pins using the list above. Try not to lean the cable against the heatsink.

Step 5 - Connect the Nano to your Laptop

  • Plug the USB Serial Cable into your laptop.

Step 6 - Plug in the power supply

I recommend using a power supply with an on/off switch, like this one:

Before you insert the plug into the Nano you can verify the switch is off by making sure the switches LED is out.

Plug the 5V 2.5A adapter into the micro-USB port on the Nano. Don't turn on the Nano just yet.

Step 7 - Login to the Nano over USB Serial

  • In a Terminal window run the following command:
    • screen /dev/cu.usbserial* 115200 -L
  • Turn on the Nano (or just plug it in if you aren't using a power supply with a switch)
  • You may need to hit Enter twice to see something
  • Select: 1: primary kernel
  • You should be prompted for a login like this -- your hostname (jet1) will be different:
Ubuntu 18.04.2 LTS jet1 ttyS0

jet1 login:

Login using the same username and password that you created when you setup the desktop.

Step 8 - Shutdown the Nano

When you are done using the Nano you should do a clean shutdown and not just unplug it. This makes sure that no files are left open, locked, etc. It also reduces the chance of corrupting the SD card.

To shutdown the Jetson Nano, run this from the command line:

sudo shutdown -h now

Step 9 - Close the screen

After properly shutting down the Nano, you can exit the screen by doing the following:

  • Press Ctrl-A
  • Press Ctrl-K
  • Select Yes

References



About the Author

Mitch Allen works for a robotics company in New England.