Rafael Ignacio Zurita wrote: > Thanks a lot if you can guide this idea!.. Let me start studying > your ideas and those projects. Naturally, I would prefer to write > all the first tests in C.
Perhaps a good start would be to access the 8:10 card port and output a square wave (just by bit-banging). The basics for this are in http://projects.qi-hardware.com/index.php/p/wernermisc/source/tree/master/spiio/spiio.c You should notice a bit of jitter. Next, you can try to control the timing better using some of the tricks of ubb-vga: http://projects.qi-hardware.com/index.php/p/ben-blinkenlights/source/tree/master/ubb-vga/ubb-vga.c Especially disable_interrupts and disable_lcd. Also the timer code may be useful, because it will give you a much easier time reference than instruction timing. With a little luck, you may be able to do without disabling the LCD, only a minimum of interrupt disabling, and just synchronize the bit timing with the timer. For USB references, this is a good and compact introduction: http://www.beyondlogic.org/usbnutshell/ At some point in time you'll need the official specification: http://www.usb.org/developers/docs/usb_20_071411b.zip (file usb_20.pdf) Or you could also pick the old revision 1.1, which doesn't have high-speed: http://esd.cs.ucr.edu/webres/usb11.pdf (The USB 2.0 spec mixes low-speed, full-speed, and high-speed all over the place. Things are clearly marked, but it's still inconvenient if you have to skip over all those high-speed things.) - Werner _______________________________________________ Qi Hardware Discussion List Mail to list (members only): [email protected] Subscribe or Unsubscribe: http://lists.en.qi-hardware.com/mailman/listinfo/discussion
