Skip to main content

FTDI device driver

Project description

========
PyFtdi
========

Overview
~~~~~~~~

PyFtdi aims at providing a user-space driver for modern FTDI_ devices,
implemented in pure Python language.

Modern FTDI_ devices include:

* FT2232D (dual port, clock up to 6 MHz)
* FT2232H (dual port, clock up to 30 MHz)
* FT4232H (quad port, clock up to 30 MHz)

Other FTDI_ devices could also be supported (including FT232* devices),
although these devices are not a primary goal for PyFtdi, and therefore have
not been tested with PyFtdi.

Primary goals
~~~~~~~~~~~~~

It should support the following modes:

* UART/Serial USB converter, up to 12Mbps (depending on the FTDI device
capability)
* SPI master
* JTAG master
* Bitbang/GPIO support (not a primary goal)

PyFtdi should provide a pyserial_ compliant API, to be used as a drop-in module
to access USB-serial converters based on FTDI_ devices.

.. _FTDI: http://www.ftdichip.com/
.. _pyserial: http://pyserial.sourceforge.net/


Requirements
~~~~~~~~~~~~

PyFtdi relies on PyUSB_, which itself depends on one of the following native
libraries:

* libusb-1.0 (recommended), currently tested with 1.0.9
* libusb-0.1 (deprecated), currently tested with 0.1.4
* openusb (not tested with pyftdi)

PyFtdi does not depend on any other native library, and only uses standard
Python modules.

To use the serial port feature of PyFtdi, pyserial_ 2.6+ module should be
installed. Previous versions of pyserial_ will NOT work.

Python_ 2.6 or above is required. Python_ 3.x is not yet supported.

.. _PyUSB: http://sourceforge.net/projects/pyusb/
.. _Python: http://python.org/


Status
~~~~~~

This project is still at an early alpha development stage.

However, PyFtdi is being forked from a closed-source software implementation
that has been successfully used for over a year - including serial, spi and
jtag protocols, based on top of the libftdi_ open source library.

libftdi_ is now being phased out from this closed-source project and replaced
with PyFtdi, to ease maintenance and customization.

Meanwhile, PyFtdi is developed as an open-source solution.

Supported features
------------------
* All FTDI device ports (UART, MPSSE) can be used simultaneously.
* Serial port, up to 12 Mbps. PyFtdi includes a pyserial_ emulation layer that
offers transparent access to the FTDI serial ports through a pyserial_-
compliant API. The ``serialext`` directory contains a minimal serial terminal
demonstrating the use of this extension, and a dispatcher automatically
selecting the serial backend (pyserial_, PyFtdi), based on the serial port
name.
* SPI master. PyFtdi includes several examples demonstrating how to use the
FTDI SPI master with a pure-Python serial flash device driver for several
common devices. For now, SPI Mode 0 (CPOL=0, CPHA=0) is the only supported
mode. It should be easy to extend the SPI master to deal with less common
modes. These tests show an average 470 KB/s read out from flash devices
running with a 6 MHz SPI clock on a Core2Duo Mac Book Pro.
* JTAG is under development and is not fully supported yet.

.. _libftdi: http://www.intra2net.com/en/developer/libftdi/

Installation
~~~~~~~~~~~~
Since PyUSB 1.0.0a2, USB bus enumeration can be performed without applying
any patch.

* Download pyusb-1.0.0a3
* Install pyusb
* Install pyftdi

Troubleshooting
---------------

*"Error: No backend available"*
libusb native library cannot be loaded. Try helping the dynamic loader:

* On Linux: ``export LD_LIBRARY_PATH=<path>``

where <path> is the directory containing the ``libusb-1.*.so`` library file

* On Mac OS X: ``export DYLD_LIBRARY_PATH=.../lib``

where <path> is the directory containing the ``libusb-1.*.dylib`` library
file

Development
~~~~~~~~~~~

PyFtdi is developed on Mac OS X platforms (including 64-bit kernels), and is
validated on a regular basis on Linux hosts.

As it contains no native code, it should work on any PyUSB_ and libusb_
supported platforms. However, Ms Windows is a seamless source of issues and is
not supported. Your mileage may vary.

.. _libusb: http://www.libusb.org/

Examples
~~~~~~~~

See the developer page available from http://github.com/eblot/pyftdi for SPI
and JTAG examples.

.. include:: serialext/README.rst

Project details


Supported by

AWS AWS Cloud computing and Security Sponsor Datadog Datadog Monitoring Fastly Fastly CDN Google Google Download Analytics Microsoft Microsoft PSF Sponsor Pingdom Pingdom Monitoring Sentry Sentry Error logging StatusPage StatusPage Status page