This is from the Super Quick installation procedure from the official PlatformIO documentation:
python3 -c "$(curl -fsSL https://raw.githubusercontent.com/platformio/platformio/master/scripts/get-platformio.py)"
sudo apt -y install rustc libffi-dev
echo "export PATH=\$PATH:/home/${USER}/.platformio/penv/bin" >> ~/.profile
Run it as user (whatever user you want to use PlatformIO as – by default, this is the pi user) and not as root!
After running these commands, log out and log back in again in order for the changes to the PATH environment variable to take effect.
After that, run
pio remote agent start
to complete the installation procedure. This will take quite some time.
After logging in, you can use pio from the shell:
$ pio Usage: pio [OPTIONS] COMMAND [ARGS]... Options: --version Show the version and exit. -f, --force DEPRECATE -c, --caller TEXT Caller ID (service) --no-ansi Do not print ANSI control characters -h, --help Show this message and exit. Commands: access Manage resource access account Manage PlatformIO account boards Embedded board explorer check Static code analysis ci Continuous integration debug Unified debugger device Device manager & serial/socket monitor home GUI to manage PlatformIO lib Library manager org Manage organizations package Package manager platform Platform manager project Project manager remote Remote development run Run project targets (build, upload, clean, etc.) settings Manage system settings system Miscellaneous system commands team Manage organization teams test Unit testing update Update installed platforms, packages and libraries upgrade Upgrade PlatformIO to the latest version