[quoted lines by lutz kaiser on 2010/08/06 at 11:08 +0200] >i found a better way: >some seconds after starting brltty >echo \002\033b >/dev/ttyUSB0
I now understand what's going on. It's a problem we're actually familiar with whenever a device is connected via USB. Since the CombiBraille uses serial I/O, I didn't recognize what was going on until I realized that you're using a USB to serial adapter. As part of USB communications, there's what amounts to a flag which is commonly called the endpoint data toggle. It has to be in the same state on both the host and the device else data isn't transferred. For reasons that I don't understand, whenever we open a USB device on Linux there's a seemingly high probability (perhaps 50%) that the data toggle is out of sync. All of our drivers which support direct USB I/O silently hide this problem by trying up to three times to get a response from the device. I guess there's also a risk of this problem occurring for serial devices if a USB to serial adapter is being used. Am I correct in understanding that this problem didn't used to happen to you? Can you remember what change in your system or way of doing things caused it to start happening? Is it, perhaps, that you used to use a direct serial connection, and that the problem started occurring when you started to use the adapter? -- Dave Mielke | 2213 Fox Crescent | The Bible is the very Word of God. Phone: 1-613-726-0014 | Ottawa, Ontario | 2011 May 21 is the Day of Judgement. EMail: [email protected] | Canada K2A 1H7 | 2011 Oct 21 is the End of the World. http://FamilyRadio.com/ | http://Mielke.cc/bible/ _______________________________________________ This message was sent via the BRLTTY mailing list. To post a message, send an e-mail to: [email protected] For general information, go to: http://mielke.cc/mailman/listinfo/brltty
