The following aims to be a concise guide of what you need to get your hardware wallet working with Electrum.
If you use the AppImage, that already has all the dependencies and Python libraries bundled with it, so skip the first two steps.
Currently all hardware wallets depend on hidapi, to be able to build
that, you need:
ubuntu:
sudo apt-get install libusb-1.0-0-dev libudev-dev
fedora:
sudo dnf install libusb-devel systemd-devel
(Package names may be different for other distributions.)
Then, depending on the device you have, you need a python package (typically a library by the manufacturer). For a usually more up-to-date list (including potential version requirements), refer to requirements-hw.txt in the client source.
python3 -m pip install trezor[hidapi]
For more details, refer to python-trezor.
python3 -m pip install hidapi btchip-python ecdsa ledger-bitcoin
For more details, refer to LedgerHQ/app-bitcoin-new and LedgerHQ/btchip-python.
python3 -m pip install keepkey
For more details, refer to python-keepkey.
The Digital Bitbox only needs hidapi.
python3 -m pip install hidapi
python3 -m pip install bitbox02
For more details, refer to python-bitbox02.
python3 -m pip install safet
For more details, refer to python-safet.
python3 -m pip install ckcc-protocol
For more details, refer to ckcc-protocol.
python3 -m pip install pyserial cbor2
For more details, refer to jadepy.
You will need to configure udev rules. See electrum/contrib/udev
That's it! Electrum should now detect your device.