2014-05-09 12:25 GMT+03:00 Rui Barreiros <[email protected]>:
> Hi, > > I was never able to solve that issue, I just gave up on reading DMX with > any FTDI device using software and went the MCU path by using AVR (that > particular project was an ATMega8). > > The problem was not chip specific in my case, because in windows using > FTDI D2XX direct driver implementation over windows I managed to properly > parse the DMX signal and read it without any complication, but since I > needed it to work under linux I had to abandon it and go the MCU route. > Hi Rui, Thanks for the response! I asked on the OLA IRC channel if someone had your details but this also works :) > > I didn't research enough to figure out where the problem lies (libusb, > libftdi, etc) due to time constraints. > What you say here at least already helps a lot because it means it's something in libftdi/libusb/linux and that it's something we can fix... > > Good luck. > Thanks! Eli > > > On 05/08/2014 11:29 PM, E.S. Rosenberg wrote: > > > 2014-05-09 1:27 GMT+03:00 E.S. Rosenberg < > [email protected]>: > >> Hi all, >> >> Several years ago Rui Barreiros already posted a question on the subject >> which at the time doesn't seem to have been resolved and I am running into >> the same problem more or less: >> >> The DMX packet is read but ends up shifted over different amounts of >> bit every read. >> >> I currently suspect that this is all dependent on when the OS issues >> the ftdi_read_data() call, I suspect this because when I ran my test >> program using gdb the shifts were a lot more extreme (almost 0.5 packet) >> then when it was running directly. >> >> The packet itself is basically: >> 1. BREAK (>= 88us of LOW) >> 2. MAB (>= 8us HIGH) >> 3. 25-513 data slots (1b start HIGH, 8b data, 2b STOP HIGH each) >> >> So my question is: Is there any way to 'allign' the reads to the >> break+mab? >> >> attached is my modified version of the serial_test.c example. >> >> Side questions: >> - Can someone on the list explain the different flow control options? >> - What is the RTS? >> >> Thanks, >> Eliyahu - אליהו >> > > I meant to also add a link to the other thread: > http://developer.intra2net.com/mailarchive/html/libftdi/2012/msg00171.html > > The device I am using is a USB-COM485-Plus4 > > Thanks, > Eli > > ------------------------------ > > *libftdi* - see http://www.intra2net.com/en/developer/libftdi for details. > To unsubscribe send a mail to [email protected] > > > > -- > > *Rui Barreiros* > [email protected] > Tlm: +351 962 356 020 > > Rua Alminhas das Cais, 950 > 4410-497 Serzedo VNG > Portugal > NIF: 506 107 523 > Tlm: +351 968 015 215 > Tlf: +351 227 625 805 > Fax: +351 227 534 304 > [email protected] > > > > ------------------------------ > > *libftdi* - see http://www.intra2net.com/en/developer/libftdi for details. > To unsubscribe send a mail to [email protected] > > -- libftdi - see http://www.intra2net.com/en/developer/libftdi for details. To unsubscribe send a mail to [email protected]
