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Author Topic: FT4222_FAILED_TO_READ_DEVICE ... every now and then.  (Read 28302 times)


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FT4222_FAILED_TO_READ_DEVICE ... every now and then.
« on: March 28, 2024, 09:19:04 pm »

We have systems communication over I2C with a Windows machine acting as master. The system will chug along doing millions of messages over weeks or months just fine, or it may run for a few hours then get an FTDI error. When this happens, the program is usually locked up (spinny blue donut) and we have to force quit or restart Windows.

When that happens, I do not expect there is anything we can do about it.

But other times, we'll sometimes get back the error 1011 (failed to read device) error and not lock up, but all further I2C writes will be failing with errors.

Do we have any hope of finding a way to prevent this from happening?

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Re: FT4222_FAILED_TO_READ_DEVICE ... every now and then.
« Reply #1 on: March 29, 2024, 04:37:00 pm »


Please confirm which version of the D2xx driver and LibFT4222 that you are using?

Are you using custom FT4222H hardware? Do you see the same issue with our UMFT4222EV-D?

Could the I2C slave be at fault rather than the FT4222H I2C master?

When this happens maybe you can perform a software reset rather than having to force quit or restart?
See FT4222_ChipReset API. You can also try these D2xx based APIs:


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