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Discussion - Hardware / FTDI Comunication Problem - Sometimes FTDI cannot be found
« on: September 01, 2022, 07:37:31 AM »
Hallo,
i am working on a FPGA project and now facing a sporadic problem.
our project is about image capture device. we are using FTDI to transfer image data and command between device and host (computer). the ftdi is conneted to a on chip USB controller HUB. the FTDI is as self-powered mode configured. there are also some other chips connected with the on chip USB controller hub.
problem:
in the most time the system works good, but just sometimes, maybe in every 20-30 reconnecting, it can happen once, that the FTDI cannot be found in device manager (neither in USBview). the other chips which are also connected to the Hub are always ok, so I think the problem could by FTDI chip. So I mesured the critical pins value of FTDI like VBUS, WAKEUP, RESET and also the power supply for it. They are all correct.
From my side I think the reason could not be failed initialization of FTDI, because I didn't have to reboot the whole system but just reconnect it, then the FTDI appears again.
So I think, if it could be caused by unstable VBUS. But according to my mesurement there is no any glitch by VBUS when the problem happens.
Another weird point is that sometimes I can hear the correct beep, even when the issue happens. that means, we should have two chips registering in the device manager, and I can hear two times windows prompt tone when our device is being connected to pc, but I can not see the FTDI in device manager. And if when I focus on the USBView(a usb port tool), I am sure I can see somethings showing up on the port where the FTDI should be. But it disappers immeditaly.
at last I want to mention again, all these failures happen only randomly, around once in 20-30 reconnecting. most time it works fine.
I am looking forward for your help
Thanks a lot
YJH
i am working on a FPGA project and now facing a sporadic problem.
our project is about image capture device. we are using FTDI to transfer image data and command between device and host (computer). the ftdi is conneted to a on chip USB controller HUB. the FTDI is as self-powered mode configured. there are also some other chips connected with the on chip USB controller hub.
problem:
in the most time the system works good, but just sometimes, maybe in every 20-30 reconnecting, it can happen once, that the FTDI cannot be found in device manager (neither in USBview). the other chips which are also connected to the Hub are always ok, so I think the problem could by FTDI chip. So I mesured the critical pins value of FTDI like VBUS, WAKEUP, RESET and also the power supply for it. They are all correct.
From my side I think the reason could not be failed initialization of FTDI, because I didn't have to reboot the whole system but just reconnect it, then the FTDI appears again.
So I think, if it could be caused by unstable VBUS. But according to my mesurement there is no any glitch by VBUS when the problem happens.
Another weird point is that sometimes I can hear the correct beep, even when the issue happens. that means, we should have two chips registering in the device manager, and I can hear two times windows prompt tone when our device is being connected to pc, but I can not see the FTDI in device manager. And if when I focus on the USBView(a usb port tool), I am sure I can see somethings showing up on the port where the FTDI should be. But it disappers immeditaly.
at last I want to mention again, all these failures happen only randomly, around once in 20-30 reconnecting. most time it works fine.
I am looking forward for your help
Thanks a lot
YJH