Re: [pyusb-users] Accessing FT4232

[Emmanuel B. <ebl...@gm...>]

On Thu, Nov 17, 2016 at 1:26 AM, Geoff Roddick <geo...@gm...> wrote:
> Hi,
>
> I'm have been unable to access the 2nd, 3rd or 4th port of the FTDI FT4232H.
> I can successfully bit bang or use SPI on Port A.
>
> I thought changing the interface would work, but both 0 and 1 access Port A
> and 2 gives me
> GpioException: Unable to open USB port: No such FTDI port: 2
>
> Can someone point me in the right direction?

Hi,

I nearly miss your email as I do not follow pyusb ML on a regular basis.
Which version of pyftdi are you using ? There have been some bugs and
confusions between interface and index in some previous releases of
pyftdi.

Interface 0 and 1 match the same interface: Port A (for legacy reasons)
Interface 2 matches port B
Interface 3 and 4 match port C and D, but these ports are only
UART/GPIO, not MPSSE-enabled so you will not be able to use SPI on
these ones.

The new release of PyFTDI (0.20.x) should be easier to use, and will
support URL to open a port, such as "ftdi://ftdi:4232/1”. It also
support FTDI device identification with “ftdi:///?” URL.

You may want to have a look at pyspiflash that provides a (hopefully
working :-)) example of using SPI to access SPI data flash devices.

Feel free to open a ticket on github (eblot/pyftdi), as this ML is
dedicated to pyusb, not pyftdi.

HTH,
Manu.