System Requirements
###################

Software
========

Requirements to run USB-SD-Mux properly:

* a Linux system with kernel 4.* or higher
* git
* Python3
* | Support for the Python3 Module ``venv``
  | This is part of the ``python3`` package on most distributions.
  | On Debian, however, the package ``python3-venv`` is needed.

.. note::

   The control software currently uses low-level Linux APIs and does not
   support Microsoft Windows.

Optional requirements to gain best experience:

:udev: can be used to address multiple USB-SD-Muxes on a single host using their
  serial number and access them without root-privileges.

Hardware
========

USB-Connection
--------------

Use an USB-A to USB-B Micro Cable to connect the USB-SD-Mux to a host computer.
Every standard Micro USB-Cable, with a maximum length of 1.8m, should do.

.. important:: Make sure the cable is not longer than 1.8 m.
             Using longer cables may result in problems with :term:`EMI`.

Micro SD-Card
-------------

You may use any micro SD card that suits your embedded device.
The USB-SD-Mux supports SD-Cards with 1.8 V and 3.3 V.

The SD card reader, which is integrated in the USB-SD-Mux supports SD, SDHC,
SDXC and compatible cards.

Using the USB-SD-Mux introduces an additional load and additional disturbances
for the micro SD card of your :term:`DUT`.
This can lead to problems like read errors and timeouts.

.. note::

   Many users have reported that using a slow micro SD card yields to better
   results than using a fast micro SD card.

Device-under-Test Connection
----------------------------

Insert the USB-SD-Mux directly into your Device under Test (:term:`DUT`).