On Tue, Oct 04, 2011 at 10:49:06AM -0300, Werner Almesberger wrote: > Rafael Ignacio Zurita wrote: > > Sounds really interesting!.. What about this project? > > http://instruct1.cit.cornell.edu/courses/ee476/FinalProjects/s2007/blh36_cdl28_dct23/blh36_cdl28_dct23/index.html > > Ah, very nice find ! This one is even closer to what we need > than V-USB.
Great. Saved. > > Do you think it is something similar? If I understand well > > it is a software usb host implementation right? > > Yup. You probably still would have to write it from scratch > for MIPS and Linux (different assembler, very different timing, > different APIs, etc.), but I should be very useful as a guide. > > Given that the Ben's core runs MUCH faster than its peripherals, > it may even be possible to do this entirely in C. E.g., ubb-vga, > which also has tight timings, is also written entirely in C. 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. > > I mean, for example, could we use > > UBB to plug some usb keyboard? > > That's what I'd do, yes. UBB, a USB A receptacle, one pull-down > resistor, and a bit of ribbon cable should get you quite far. > > I'm not quite sure what needs to be done with the supply > voltage. The correct solution would be to have a boost converter > that converts the 3.3 V from the Ben to the 5 V USB expects. > For this, you would need to make a real PCB. > > But maybe we can get away with supplying only 3.3 V. According > to the data sheets, the ATmega32U2 (atusb) would want at least > 4.0 V on VBUS. The C8051F326 (idbg) would already be content > with 2.9 V. So it doesn't seem unreasonable to expect that a > number of USB devices work fine with VBUS = 3.3 V. > > > No sure if I understand, but if the hardware part is something > > easy to get, at least for testing or starting point then more > > people could like the idea. At least it looks interesting > > for me, and I could start a 10 years software project to try that :) > > Excellent ! ;-) Now, let's see what we can do about that > hardware ... Cool :) Rafa _______________________________________________ Qi Hardware Discussion List Mail to list (members only): [email protected] Subscribe or Unsubscribe: http://lists.en.qi-hardware.com/mailman/listinfo/discussion
