Jetson Nano USB Login (A02, B01)

This article covers how to connect and login to an NVIDIA Jetson Nano using a USB serial cable.

Instructions for connecting with a Micro-USB connector can be found here: Jetson Nano Micro-USB Login (A02, B01).

This article assumes you have already setup a username and password on your Jetson Nano. If you would like to start from scratch with a headless setup, see my article: Jetson Nano Headless WiFi Setup.

These instructions were tested using the Jetson Nano Developer Kit SD Card Image JetPack 4.4 dated 2020/04/21.

Step 1. 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:

Note: I was unable to get this to work on a Mac using a USB-C to USB-A driver. Please be aware of that before you purchase anything.

Step 2. 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 3. Wire the USB serial cable to the Nano

Where you connect the serial cable on the Nano depends on which carrier board you have.

There are currently two versions:

  • A02 - the original carrier board
  • B01 - available as of the year 2020

The newer version (B01) has two camera connectors on the side (J13 and J49).

Follow the instructions below for whichever carrier board you have.

Jetson Nano Development Kit Carrier Board A02

For the A02 version of the carrier board, the serial connectors are on J44.

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.

Jetson Nano Development Kit Carrier Board B01

For the B01 version of the carrier board, the serial connectors are on J50.

Flip the board over and you will see the labels for a 12 pin header at the back.

Connect the USB Serial cable to the following pins on J50:

  • UART RXD (Pin 3) - Receive (Green Wire (TX) -> RXD)
  • UART TXD (Pin 4) - Transmit (White Wire (RX) -> TXD)
  • GND (Pin 7) - Ground (Black Wire (GND) -> GND)

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

Step 4. Connect the Nano to your computer and power

  • Plug the USB Serial Cable into your computer or laptop
  • Plug a power supply into the Jetson Nano

Step 5. 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 once or twice to see something
  • On old versions you may be given some options, if you see 1: primary kernel select it
  • You should be prompted for a login like this – your hostname (in my case jet1) will be different:
Ubuntu 18.04.4 LTS jet1 ttyS0

jet1 login: 
  • Login using the same username and password that you created when you setup the desktop.

Step 6. 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 7. 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 Y (for Yes)

Here is a list of additional articles that I’ve written up for the Jetson Nano:

  • Jetson Nano Power Supply (Barrel vs MicroUSB) - When you get a Jetson Nano Developer Kit, the first thing you need to figure out is how to power it. Should you use the Micro USB port with the same 5V 2.5A power supply you use on a Raspberry Pi? Or should you invest in a 5V 4A barrel jack power supply? In this article I answer that question.
  • Jetson Nano USB Headless WiFi Setup (Edimax-EW-7811UN) - The easiest way to setup a Jetson Nano for headless WiFi is to use a USB adapter. The EdiMax EW-7811Un is popular for use with the Raspberry Pi. It can also be used with a Nano, but requires a command line setting to get it to act reliably. In this article I show you how to set it up
  • How to add a dual WiFi Bluetooth card to a Jetson Nano (Intel 8265) - In this post I show advanced users how to upgrade to an Intel Dual Band Wireless card that will also provide Bluetooth functionality
  • My frequently updated Jetson Nano Resource Guide - check it out if you need things like a wireless keyboard and trackpad that fits in your pocket

References

  • screen utility manual for OSX [1]



About the Author

Mitch Allen works for a robotics company in New England.