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lsgunth / pyft232

Python bindings to d2xx and libftdi to access FT232 chips with the same interface as pyserial
GNU Lesser General Public License v2.1
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Using CBUS as output #7

Closed JBSchueler closed 6 years ago

JBSchueler commented 6 years ago

I am trying to use this library to access CBUS0 and CBUS1. I copied the example and run it on my PC (windows 10). The program runs, I see text coming out via the TX line but the CBUS doesn't change a bit.

Has the README.md example been tested on a windows machine? Did I forget something?

ftditest.zip image

lsgunth commented 6 years ago

Yes, it's been tested in windows, however that was a very long time ago.

Have you set the cbus bits in the eeprom using the FT_PROG?

Logan

JBSchueler commented 6 years ago

Yes, I tried BitBang WRn. But I am not sure what to use.

What I noticed is when I change e.g. CBUS0 to BitBang WRn and program the EEprom via image, unplug and replug the USB, CBUS has it's default value again (in my case TXLED#)

image

JBSchueler commented 6 years ago

Seems the chip I am using is a "fake" one.... I am not able to change the settings of the EEPROM.

JBSchueler commented 6 years ago

How to determine if your FTDI chip is fake.

If the serial is A50285BI, it is a fake one. There is not even an EEPROM within this chip, although it says 93C56 EEPROM. image

The only way to make it work is to use an official FTDI chip. And if you want to use your breakout board, this means that you have to replace the FTDI chip.

Russell Graves spend a blog on this topic and how to change the chips.

lsgunth commented 6 years ago

Ah, good to know. Thanks for the information. I suspect you were supposed to use I/O mode, but it's been a long time and I can't remember for sure.

Logan