Setting Environment Variables

PYNQ.remote uses the PYNQ_REMOTE_DEVICES environment variable to identify and configure remote devices. Windows, Linux, and macOS all use different methods to set environment variables. This document aims to provide a brief overview of how to set this variable across different platforms. For more details, refer to the documentation for your specific operating system.

Setting an Environment Variable in Python

You can set environment variables in Python using the os module. This is useful if you want to set the variable programmatically before importing the pynq package. This is the preferred method, as it works across all operating systems and does not require any additional setup in your shell.

import os
os.environ['PYNQ_REMOTE_DEVICES'] = "192.168.2.99"

Setting an Environment Variable in Linux and macOS

In Linux and macOS shells, you can set environment variables using the export command. Make sure there are no spaces around the = sign.

export PYNQ_REMOTE_DEVICES="192.168.2.99"

The code above sets the environment variable for the current shell session. If you use a new terminal or restart your computer you will need to set it again.

Setting an Environment Variable in Windows

In Windows, there are several ways to set environment variables, depending on which shell you are using. For Command Prompt (cmd.exe), you can use the set command:

set PYNQ_REMOTE_DEVICES=192.168.2.99

For Powershell, you can use the $env: syntax:

$env:PYNQ_REMOTE_DEVICES="192.168.2.99"

Setting an Environment Variable in a Python Virtual Environment

If you are using a Python virtual environment, you can set the environment variable in the activate script of your virtual environment. This way, the variable will be set automatically each time you activate the virtual environment.

For example, if you are using a virtual environment named venv, you can add the code above in the following directories:

For Linux/macOS: Add the code above to the venv/bin/activate
For Windows: If using Command Prompt, add the code to venv/Scripts/activate.bat
For Windows: If using PowerShell, add the following line to venv/Scripts/Activate.ps1