On Sunday, 27. May 2012 23:32:08 Matthew Stock wrote: > Hello, > > I was wondering if anyone had some examples of using the library > successfully using software flow control? I ask because I have an > application that requires it, and I'm not sure how the FTDI library (or > the underlying USB library) handle the in-band XON/XOFF signalling. > Looking at the libftdi code, I can't see how writes are throttled, and > it seems odd to me that it would be handled in the generic USB code > (e.g. having the bulk write block). > > I'm not using the library directly - I'm implementing support for FTDI > on Android for a project, and I've been referencing the libftdi code. > It's been incredibly helpful. Everything is working really well until I > start to write a lot of data. I'm trying to narrow the problem down - > an incomplete understanding of FTDI, a bad implementation on my part, a > problem with Android, etc.
libftdi doesn't have built in support for XON/XOFF, you have to handle this at the application level. libftdi was written for the bitbang mode in mind in the first place, nowadays it does much more of course. I don't think it will be part of the core library, since it really implements a (common) protocol on top of libftdi. Most people who need full RS232 communication stick to the ftdio_sio kernel driver. The wikipedia page on software flow control http://en.wikipedia.org/wiki/Software_flow_control#Comparison_with_hardware_flow_control has a good summary why XON/XOFF is "problematic" :) Thomas -- libftdi - see http://www.intra2net.com/en/developer/libftdi for details. To unsubscribe send a mail to [email protected]
