Install Jetson Nano Developer Kit on your Jetson Nano

We decided to try getting Blinka running in the Jetson Nano Developer Kit because that's the recommended installation available for the Jetson Nano. Other distros could be made to work but you'd probably need to figure out how to detect the platform. Using other operating systems and CircuitPython is your call, we cannot provide support for that.

Due to the size of the Dev Kit Image, you will need at least a minimum of a 16GB SD card.

Download and install the latest Jetson Nano Developer Kit, for example we're using https://developer.nvidia.com/embedded/learn/get-started-jetson-nano-devkit#write

There's some documentation to get started at https://developer.nvidia.com/embedded/learn/get-started-jetson-nano-devkit

Preparing the Board

Logging in

Once you have completed the wizard, you can either continue using that, connect a serial console cable, or log in through SSH. We've found the easiest way to connect is through a console cable, wired to the J44 connector and then on your computer, use a serial monitor at 115200 baud.

You can also connect via SSH using either the command prompt on a Mac or Linux computer or using a terminal program such as PuTTY on Windows. In either case, you will need your username and hostname from earlier in the setup wizard.

You may need to reboot the Jetson Nano after completing the wizard before the device will show up on your network.

Connect the RX, TX and ground wires of the console cable like so:

Log in to get to a shell. In this guide, we will be using the user pi just to keep things consistent with other guides. Change the commands to use whatever username you ended up using.

Set your Python install to Python 3 Default

There's a few ways to do this, we recommend something like this:

sudo apt install -y python3 git python3-pip
sudo update-alternatives --install /usr/bin/python python $(which python2) 1
sudo update-alternatives --install /usr/bin/python python $(which python3) 2
sudo update-alternatives --config python

sudo apt install -y python3 git python3-pip
sudo update-alternatives --install /usr/bin/python python $(which python2) 1
sudo update-alternatives --install /usr/bin/python python $(which python3) 2
sudo update-alternatives --config python

Install Python 3.8 and Make Default

You can install Python 3.8, but it won't be the default Python. However, you can do something like above:

sudo apt install -y python3.8
sudo update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.6 1
sudo update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.8 2
sudo update-alternatives --config python3

sudo apt install -y python3.8
sudo update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.6 1
sudo update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.8 2
sudo update-alternatives --config python3

Now run python --version and it should show some version of Python 3.8:

Update Your Board and Python

Run the standard updates:

sudo apt update

sudo apt upgrade

and

sudo pip3 install --upgrade setuptools

Update all your Python 3 packages with

pip3 freeze - local | grep -v '^\-e' | cut -d = -f 1 | xargs -n1 pip3 install -U

and

sudo bash

pip3 freeze - local | grep -v '^\-e' | cut -d = -f 1 | xargs -n1 pip3 install -U

Nano (no relationship to the board), which is very handy for quickly editing python scripts, isn't installed by default. So let's add that:

sudo apt install nano

Enable UART, I2C and SPI

A vast number of our CircuitPython drivers use UART, I2C and SPI for interfacing, so you'll want to get those enabled.

I2C and UART are enabled by default, so you don't need to take any additional steps.

To enable SPI, you will need to run the Jetson-IO utility. Be sure your terminal window is expanded first, or it may not display the full utility:

sudo /opt/nvidia/jetson-io/jetson-io.py

After the Nano boots up again, verify you have the I2C devices with the command ls /dev/i2c* /dev/spi*

You should see at least one I2C device and one SPI device

The UART Serial Console on the Jetson Nano is connected to /dev/ttyS0. The UART GPIO Serial Port is connected to /dev/ttyTHS1.

Set User Permissions

In order to use the Jetson GPIO Library, the correct user permissions/groups must be set first. Start by creating a new gpio user group.

sudo groupadd -f -r gpio
sudo usermod -a -G gpio pi

Clone the Repo and copy the rules

cd ~
git clone https://github.com/NVIDIA/jetson-gpio.git
sudo cp ~/jetson-gpio/lib/python/Jetson/GPIO/99-gpio.rules /etc/udev/rules.d

Now reboot so that the new rules take place.

Install Python Libraries

Now you're ready to install all the Python support.

Next, run the following command to install adafruit_blinka:

pip3 install adafruit-blinka

The computer will install a few different libraries such as Adafruit-PureIO (our ioctl-only i2c library),  Jetson.GPIO (for handling GPIO), Adafruit-PlatformDetect (for detecting your board) and of course adafruit-blinka.

That's pretty much it! You're now ready to test.

Create a new file called blinkatest.py with nano or your favorite text editor and put the following in:

import board
import digitalio
import busio

print("Hello blinka!")

# Try to great a Digital input
pin = digitalio.DigitalInOut(board.D4)
print("Digital IO ok!")

# Try to create an I2C device
i2c = busio.I2C(board.SCL, board.SDA)
print("I2C 1 ok!")
i2c = busio.I2C(board.SCL_1, board.SDA_1)
print("I2C 2 ok!")

print("done!")

import board
import digitalio
import busio

print("Hello blinka!")

# Try to great a Digital input
pin = digitalio.DigitalInOut(board.D4)
print("Digital IO ok!")

# Try to create an I2C device
i2c = busio.I2C(board.SCL, board.SDA)
print("I2C 1 ok!")
i2c = busio.I2C(board.SCL_1, board.SDA_1)
print("I2C 2 ok!")

print("done!")

Save it and run at the command line with

python3 blinkatest.py

You should see the following, indicating digital i/o, I2C and SPI all worked