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FT232H GPIO access using VCP driver

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brumbarchris:
Hello all,
I am using one of the FTDI C232HD USB 2.0 HI-SPEED TO UART CABLE.
The schematic of this cable indicates the Q1 P-FET on the VCC line, which can be used to cut off the supply to whatever device is supplied from this cable. This transistor is controlled by the ACBUS9 pin of the FT232H IC on which this cable is based.


I would like to control this pin so that I can programatically cut off power to the device I use. Do you know if this can be done using the VCP drivers and UART operating mode? (I do not control the software on the PC side, which is done by another "entity"; so using the D2XX drivers is not an option).

I know that with a one-time use of FT_PROG I can configure the ACBUS9 pin to operate as a GPIO and the following statement exists in the FT232H datasheet:


--- Quote ---The ACBUS pins can also be individually configured as GPIO pins, similar to asynchronous bit bang mode. It is possible to use this mode while the UART interface is being used, thus providing up to 4 general purpose I/O pins which are available during normal operation.
--- End quote ---

However, this statement is not clear whether operating this pins as GPIO mode while the UART interface is being used is possible using the D2XX drivers only, or if it can be done using VCP too (anything I write to the COM port would be transparently transmitted further by the FTDI chip, I do not know how to send commands to the FTDI chip itself using the VCP driver only).

Regards,
Cristian

PCB.Wiz:
I think the normal usage is to operate as PWREN# which is low when the port is open() and high when closed()
Is that enough control for you?

brumbarchris:
Thanks for the reply. This helped a lot!

I found out the pin was already configured as PWREN#, but I had to enable the selective suspend feature in the option drivers, in order to get any reaction from it.

Regards,
Cristian

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