ftdi-cbus-ctrlep.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# Author: Stefan Agner

import os
import sys
import time
import usb

BITMODE_CBUS = 0x20

SIO_SET_BITMODE_REQUEST = 0x0b

# FTDIs CBUS bitmode expect the following value:
# CBUS Bits
# 3210 3210
#      |------ Output Control 0->LO, 1->HI
# |----------- Input/Output   0->Input, 1->Output

# PyUSB control endpoint communication, see also:
# https://github.com/pyusb/pyusb/blob/master/docs/tutorial.rst

def ftdi_set_bitmode(dev, bitmask):
    bmRequestType = usb.util.build_request_type(usb.util.CTRL_OUT,
                                                usb.util.CTRL_TYPE_VENDOR,
                                                usb.util.CTRL_RECIPIENT_DEVICE)

    wValue = bitmask | (BITMODE_CBUS << 8)
    dev.ctrl_transfer(bmRequestType, SIO_SET_BITMODE_REQUEST, wValue)

def main():
    """Main program"""
    dev = usb.core.find(custom_match = \
            lambda d: \
                d.idVendor==0x0403 and
                d.idProduct==0x6001 and
                d.serial_number=="A10XXXXX")

    # Set CBUS2/3 high...
    ftdi_set_bitmode(dev, 0xCC)

    time.sleep(1)

    # Set CBUS2/3 low...
    ftdi_set_bitmode(dev, 0xC0)

    # Set CBUS2/3 back to tristate
    ftdi_set_bitmode(dev, 0x00)

main()

This was very helpful. Thank you.
On windows I needed to get the backend setup, but after that it worked great: https://stackoverflow.com/questions/13773132/pyusb-on-windows-no-backend-available
Question:
Could you show how to also do the "ftdi_get_bitmode()" function to read the state of the CBUS lines?

@Nathan-L-Cook you can find an example of that here: https://github.com/agners/python-sdrewire/blob/main/sdrewirectl#L34-L43

Perfect. Thank you. Using that example I am able to GET the values of the pin state (HI/LO).
One more question:
Is it possible to also GET the values of the pin mode (Input/Output)?

I am not aware off. Also, from this list, it doesn't look like.

Thanks for the link. I have a question open with the FTDI support guys. If they have an answer, I'll post it here too.

Got a feedback direct from the FTDI guys:
"I’m afraid there is no API command to determine the CBUS mode of the FT230X.
Even the D2XX FT_GetBitMode command (in bit-bang mode) will only give you the hex value on the data bus pins, not the mode."

Ok, oh well 🤷‍♂️ Thanks for posting it here.