Basic Usage

pylibftdi is a minimal Pythonic interface to FTDI devices using libftdi. Rather than simply expose all the methods of the underlying library directly, it aims to provide a simpler API for the main use-cases of serial and parallel IO, while still allowing the use of the more advanced functions of the library.


The primary interface is the Device class in the pylibftdi package; this gives serial access on relevant FTDI devices (e.g. the UM232R), providing a file-like interface (read, write). Baudrate is controlled with the baudrate property.

If a Device instance is created with mode='t' (text mode) then read() and write() can use the given encoding (defaulting to latin-1). This doesn’t make a lot of difference on Python 2 (and can be omitted), but allows easier integration with passing unicode strings between devices in Python 3.

Multiple devices are supported by passing the desired device serial number (as a string) in the device_id parameter - this is the first parameter in both Device() and BitBangDevice() constructors. Alternatively the device ‘description’ can be given, and an attempt will be made to match this if matching by serial number fails.

In the event that multiple devices (perhaps of identical type) have the same description and serial number, the device_index parameter may be given to open matching devices by numerical index; this defaults to zero, meaning the first matching device.


>>> from pylibftdi import Device
>>> with Device(mode='t') as dev:
...     dev.baudrate = 115200
...     dev.write('Hello World')

The pylibftdi.BitBangDevice wrapper provides access to the parallel IO mode of operation through the port and direction properties. These provide an 8 bit IO port including all the relevant bit operations to make things simple.

>>> from pylibftdi import BitBangDevice
>>> with BitBangDevice('FTE00P4L') as bb:
...     bb.direction = 0x0F  # four LSB are output(1), four MSB are input(0)
...     bb.port |= 2         # set bit 1
...     bb.port &= 0xFE      # clear bit 0

There is support for a number of external devices and protocols, specifically for interfacing with HD44780 LCDs using the 4-bit interface.