On Thu, May 4, 2017 at 5:42 PM, Graham Haddock <[email protected]> wrote:
> So, the COM port on Windows is talking to a virtual serial port in the BBB > USB widget. > There is no hardware UART involved, and no hardware clocks anywhere to > throttle or pace anything. > Then, you push this for transfer rate, while running it under a non > realtime OS. > I guess I am not surprised that you are having problems. > This is kind of what I'm thinking, but just sayin' Graham, "gadget" not "widgit" :P But yeah I do not know this hardware at all, but the conversion from USB to RS485, there can not be any flow control there. So the gadget side of the hardware has no flow control, where the RS485 side *may*. I'd actually speed up the transmission rate, and perhaps put in a usleep() between each send to fine tune things, and call it quits. > > The USB widget is nice for doing simple things, with fast, simple set up > for beginners. > I suspect you are trying to run it in an application where it has not been > well tested. > > For a stable system, I would recommend considering doing the data transfer > over a real hardware serial port, or if that is not fast enough, do the > transfer using Ethernet. (And I don't mean Ethernet over USB using the > Widget.) > > I find the true hardware serial ports, and the genuine FTDI serial to USB > converters to be stable well above 100,000 bits per second. Some report > success in the megabits per second range, I have just not had to personally > go there, yet. > > You never have been specific about how many bits per second of data that > you have to move. > I think that is an important place to start. > > So *maybe* if UART4 on the beaglebone was used in full RS485 mode, talking to the USB to RS485 converter connected to the Windows machine through USB. *Maybe* that could, or would help solve these issues ? Just a guess but hey probably worth looking into. -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/CALHSORoXByX_RLLcB-_SKTHYtuTfqiy05-EbsjcJaPTeivd29w%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
