pylibftdi

0.24.0 verified Mon Apr 27 auth: no python

Pythonic interface to FTDI devices using libftdi. Current version 0.24.0, requires Python >=3.10. Released under BSL-1.0, maintained on GitHub. Cadence: irregular, with recent releases in 2024.

pip install pylibftdi

Common errors

error pylibftdi.exc.FtdiError: libusb_open() failed ↓

cause No permission to access USB device or device not connected.

fix

Ensure device is plugged in and you have udev rules set. Or run with sudo (temporary).

error pylibftdi.exc.FtdiError: FTDI device not found ↓

cause The specified device_id or serial does not match any connected FTDI device.

fix

List devices with pylibftdi.Driver().list_devices() to see available serials.

error AttributeError: module 'pylibftdi' has no attribute 'FtdiDriver' ↓

cause FtdiDriver was removed in pylibftdi 0.22.0.

fix

Use pylibftdi.Driver instead.

Warnings

breaking pylibftdi dropped support for Python <3.10 in version 0.24.0. ↓

fix Upgrade Python to 3.10+ or pin pylibftdi to 0.23.x for older Python.

deprecated The 'baudrate' argument is deprecated in some contexts; use 'baud' instead. ↓

fix Replace baudrate=... with baud=... in Device constructor.

gotcha On Linux, you must have udev rules or run with sudo to access FTDI devices. Missing rules cause 'FtdiError: libusb_open() failed'. ↓

fix Add udev rule: SUBSYSTEM=="usb", ATTRS{idVendor}=="0403", ATTRS{idProduct}=="6001", MODE="0666"

gotcha When using BitBangDevice, note that pin numbering is bit index, not physical pin. Miswiring is common. ↓

fix Check datasheet: e.g., for FT232R, D0..D7 correspond to pins 1-8 (CBUS0-3 in bitbang mode).

Imports

BitBangDevice
wrong
```
from pylibftdi.device import BitBangDevice
```
correct
```
from pylibftdi import BitBangDevice
```
Public API is in pylibftdi top-level; submodules are internal.

Device

wrong

from pylibftdi.driver import FtdiDriver

correct

from pylibftdi import Device

FtdiDriver was removed; use Device directly.

Driver
```
from pylibftdi import Driver
```

Quickstart

Opens first available FTDI device in async mode, writes bytes, reads response.

import os
import time
from pylibftdi import Device
with Device(mode='t', device_id=os.environ.get('DEVICE_SERIAL', '')) as dev:
    dev.write(b'hello')
    time.sleep(0.1)
    print(dev.read(10))