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USB in software — Parallax Forums

USB in software

LeonLeon Posts: 7,620
edited 2007-06-10 15:33 in Propeller 1
Some time ago someone implemented a USB interface on an Atmel ATtiny2313 AVR running at 12 MHz:

http://www.obdev.at/products/avrusb/index.html

It should be feasible to do the same sort of thing with the Propeller. I'm not volunteering, though.

Leon

Comments

  • Peter JakackiPeter Jakacki Posts: 10,193
    edited 2007-04-16 12:49
    Ok, I'll come in on this as this is one of the things that I will be implementing as soon as I get "a round tuit". Yes, I remember the Atmel implementation and even though it ate the chip resources it worked, albeit as a simple slow-speed slave. This is fine as there is still a lot that can be done at 1.5Mbps and although it may eat up a whole cpu this is only one cog on the Propeller. So it would be rather nice to have a USB object that could also host USB HID devices as keyboards and mice are certainly all going that way.

    I mainly want to emulate HID and UART class devices but the nextgen Prop will be that much faster I would think it would be possible to easily run 12Mbps. At that speed it might even be possible to emulate a 10Mbps ethernet device at some level which almost any 10/100 ethernet interface will be happy with.

    *Peter*
  • JoannaKJoannaK Posts: 44
    edited 2007-06-10 02:16
    Sorry for a late reply.. I have been away from propeller forums couple months..

    I have been having this idea of making USB low level drivers with Propeller assembly, and was considering it (low speed mouse/keyboard type) to be my MSc thesis material, but I'm not sure if it'll be possible. I'm now in middle of finalising my BSc and I need to look out what can be done with local Uni... They aren't really too interested about Embedded like stuff.

    For timing.. I had some preliminary code segments (untested) for 1.5MBps read/write written, it needs a bit higher clock than usually (IIRC 6 MHz xtal with 16* PLL) to work.

    Edit.. sorry.. I think 6MHz oscillator and 16X pll woul be ok.. That's 96Mhz clock => 24MIps => 16 instructions/each bit in low speed Usb bus.

    Post Edited (JoannaK) : 6/11/2007 2:06:57 AM GMT
  • TransistorToasterTransistorToaster Posts: 149
    edited 2007-06-10 02:30
    Did you see this link?
    www.sxlist.com/techref/scenix/lib/io/dev/keys/usbdemo-mh.htm
  • inakiinaki Posts: 262
    edited 2007-06-10 15:09
    Take a look at this one, althought it is for AVR too:

    http://www.elektor.de/Default.aspx?tabid=27&art=5551005&PN=On



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  • TransistorToasterTransistorToaster Posts: 149
    edited 2007-06-10 15:33
    Cool! It's also based on Leon's link.
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