[chirp_users] Programming Cable Guide

[Robert Terzi]

On 11/3/2011 7:10 PM, Dan Smith wrote:
>> RT Systems are using the FTDI chip but have assigned a custom USB Vendor ID
>> and Product ID to it.  Under Linux you can use this cable (and I do
>> use it with Chirp) by telling the ftdi_sio driver the additional
>> VID/PID to look for.  I have a UDEV rule that I believe handles
>> this.
>
> Is this a "version 4" cable? Someone came to me a few months ago with
> one that didn't even show up as a COM port on Windows when properly
> configured. It seemed like maybe it was being used in native USB mode
> send/receive data to the radio and did not contain a typical serial port
> emulation device.

Yes, the FTDI chips can be used with either a Virtual Com Port (VCP)
driver which provides a COMn interface under windows and then you have to
figure out what com port to open or it can be used with a direct driver (D2XX)
where the USB bus is searched for a matching Vendor and Product ID (VID/PID).

> This would make it harder for others to use the cable,

Yes, it would be difficult for CHIRP or other cross platform software to
work with the FTDI direct interface because of the binary issues.

There are libraries (libftdi) that can be used.  I've seen stuff use
it though some of the stuff that uses it is for bit banging and other
cases where more direct control is needed.

As I mentioned there are two types of work around:

1.) Change the VID/PID <-> driver associations so you get the virtual comm port
     style driver (or the linux ftdi_sio driver to load, like in your icomsio.sh script)

or

2.) Change the VID/PID on the FTDI chip to the standard VID/PID for FTDI serial adapters.
    (which I think is in eeprom but never tried it)