[EMAIL PROTECTED] wrote: > I have been studying Roland XV-5050 managing through USB port few days > now, and been able to send "Set" commands with snd_rawmidi_write to > Roland USB module. But when trying to read e.g. Performance/Patch name > from the module with snd_rawmidi_read, I do not get any information from > the module. > > What I do when querying information from module: > 1. Sending "get" sequence with snd_rawmidi_write(rawmidi_handle_out, > &uchar, 1) to USB module > 2. Then immediatelly snd_rawmidi_read(rawmidi_handle_in, &uchar, 1) to > read the USB module. > > Normally this only hangs the test sw, but if snd_rawmidi_open with > define (0x0002 = not to wait for response), the read only gives int > value 247 for a response.
The snd_rawmidi_read/write functions are designed to work exactly like the POSIX read/write functions. For an example of nonblocking reading, see the source code of amidi. (Reading patch names works just fine with amidi and a Roland SC-8820.) HTH Clemens ------------------------------------------------------- SF.Net is sponsored by: Speed Start Your Linux Apps Now. Build and deploy apps & Web services for Linux with a free DVD software kit from IBM. Click Now! http://ads.osdn.com/?ad_id=1356&alloc_id=3438&op=click _______________________________________________ Alsa-user mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/alsa-user
