Hi Dave, You wrote:
> I see. It's a little annoying to implement because of the screen model > that splits the screen vertically every eight pixels, but not > infeasible, by a long way. > Yes, the Java code has to cope with that. We isolate it in setPixel, but that slows things down. > Hmm, from my memory of the USB spec, I don't see what you mean by > serial. From my memory, the only thing that mattered was accepting the > bus address set by the host, and declaring the correct vendor/product > ID. But I may be confused, as I didn't implement the USB driver in our > kernel, just helped debug it. > The Lego code, when requesed, returns a Serial Number Descriptor, which it makes unique by using the bluetooth address. I currently return one with all zeros. I don't think it is requested by a normal USB enumeration, but I think the Lego fantom driver might request it, as the standard Lego code and the fantom API do not recognize lejos NXJ over usb, even though the OS does and libnxt on both Linux and Windows does. >> Again the Bluetooth driver we have works well enough but has limitations. >> It >> is DMA driven like the Lego version. The C code is minimal and all the >> message protocol with the BC4 chip is handled in Java. >> >> The limitations are that data messages must have a two-byte length >> header, >> and this is inconvenient for Java streams. Also the MSB of the length is >> ignored, so messages are limited to 256 bytes. > > So this would be pushing functionality down from java into C, to > better handle bit twiddling. > I am in two minds about this. The protocol handling works well enough in Java, so we might leave that in Java. The minimum requirement is to handle the two-byte header correctly when it is there (the Lego Communications Protocol uses it), but to have a mode for Java streams when two-byte headers are not used - i.e make the C code just return what is in the DMA buffer, and not wait for a complete message. > I'm afraid that I completely missed the existence of a developer list, > as it doesn't appear to be listed on the Lejos web site. Where can I > sign up? > If you log in to sourceforge and go to the lejos project page, and select "mailing lists", you should see the lejos developers list and the svn commits list, as you are registered as a lejos developer. Lawrie ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ Lejos-discussion mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/lejos-discussion
