slightly OT: FT245 disappearing in windows?

Go To Last Post
2 posts / 0 new
Author
Message
#1
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Hello all,

I've got an FT245 USB controller hooked up to an atMega16. I'm using virtual com port drivers. Actually, there's two 245's, sharing the data port and with separate control signals. Trouble is this: One of the ports worked fine from day one. The other port I can send from the AVR to a terminal on the PC with no problems. However, as soon as I send 3 bytes to the FT245 (that is, from PC to AVR), the terminal crashes (Bray's terminal). The same effect is obtained by unplugging the device before closing the program. As soon as I reload terminal, sometimes the port is there, sometimes its gone forever and I have to reboot. For some reason, my other port that had always worked fine is now giving me the same problem.

Its always as soon as I sent that third byte. The first two are fine.

Note that this occurs without regard to the program on the AVR, in fact my most recent test was with the chip erased. Having application code loaded that gets received data from the 245 still results in the same problem.

Anybody have any ideas?

Thanks,
Jeremy

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Ok,

After some more poking around FTDI's site, I found the knowledgebase, and hidden in there was a suggestion to put 47pf caps on the USB data lines between the series resistors and the hub. I suppose there may be some glitching on those causing problems..... I'll try it tonight and let everyone know what happens, in the meantime if anyone has any other suggestions please let me know.

Jeremy