ftd2xx

1.3.8 verified Mon Apr 27 auth: no python

A Python interface to FTDI's D2XX driver (ftd2xx.dll on Windows, libftd2xx on Linux/macOS) using ctypes. Currently at v1.3.8, with a relatively stable release cadence. Compatible with Python >=3.8.

pip install ftd2xx

Common errors

error ftd2xx.DeviceError: FT_Open failed ↓

cause Device not found or driver not installed.

fix

Check device is connected and driver (ftd2xx.dll/libftd2xx) is installed. On Linux, add udev rule.

error AttributeError: module 'ftd2xx' has no attribute 'open' ↓

cause Trying to use old d2xx import pattern like 'from d2xx import open'.

fix

Use 'import ftd2xx' then 'ftd2xx.open()'.

error OSError: [WinError 193] %1 is not a valid Win32 application ↓

cause Using 32-bit ftd2xx.dll with 64-bit Python, or vice versa.

fix

Match bitness of ftd2xx.dll with Python interpreter.

Warnings

gotcha open() and openEx() by default call createDeviceInfoList which can be slow on some systems. Use update=False to avoid this when you don't need device info. ↓

fix dev = ftd2xx.open(0, update=False)

gotcha On Linux, you may need to install libftd2xx separately and configure udev rules for non-root access. Otherwise you'll get a 'Failed to open device' error. ↓

fix Install libftd2xx from FTDI's website and add udev rule: SUBSYSTEM=="usb", ATTRS{idVendor}=="0403", MODE="0666"

deprecated The older d2xx library (by Pablo Bleyer) was renamed to ftd2xx. Importing from d2xx is deprecated and will break. ↓

fix Use 'import ftd2xx' instead of 'import d2xx'

Imports

ftd2xx
```
import ftd2xx
```
DeviceError
```
from ftd2xx import DeviceError
```

Quickstart

Basic usage: list, open, reset, read/write, and close a device.

import ftd2xx

# List connected devices
device_count = ftd2xx.createDeviceInfoList()
print(f"Found {device_count} device(s)")

# Open first device by serial number (or index)
try:
    dev = ftd2xx.open(0)
    print(f"Opened device: {dev.description}")
    # Reset and set bit mode to reset default
    dev.reset()
    dev.setBitMode(0, 0)
    # Write data
    dev.write(b"Hello FTDI")
    # Read data
    data = dev.read(100)
    print(f"Read: {data}")
    dev.close()
except ftd2xx.DeviceError as e:
    print(f"Error: {e}")