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Usb?, usb?? — Parallax Forums

Usb?, usb??

davidsaundersdavidsaunders Posts: 1,559
edited 2013-03-11 17:24 in Propeller 2
Beings that a couple of people have managed bit banged USB on the Propeller, I was thinking that it should be possible to do bit banged USB with the propeller 2 a lot easier. If an external parallel to serial/serial to parallel shifter is used maybe even 480Mb/s USB 2.

I am wondering if anyone has thought about this, and if so if any one is working on this as of yet? It seems that if there is full support for at least USB 1.1 that this may be of aid getting the Propeller 2 to be more widely adopted. I do not have a DE0 Nano so I can not do much on this (I am emulating a 4 core Prop2 in software on RISC OS very very slowly), and unfortunately I can not afford a DE0 Nano.

Comments

  • Bill HenningBill Henning Posts: 6,445
    edited 2013-03-10 15:14
    I've thought about this, but I don't have time to work on it now... An HID class for low speed (1.5Mbps) would be very useful, as it would allow USB mice / keyboards, and one thread should be enough per phy. Low speed serial is against spec, but seems to work in most cases.

    12Mbps "full speed" also should work fine but would probably require a full cog.

    480Mbps is clearly impossible :)
    davidsaunders wrote: »
    Beings that a couple of people have managed bit banged USB on the Propeller, I was thinking that it should be possible to do bit banged USB with the propeller 2 a lot easier. If an external parallel to serial/serial to parallel shifter is used maybe even 480Mb/s USB 2.

    I am wondering if anyone has thought about this, and if so if any one is working on this as of yet? It seems that if there is full support for at least USB 1.1 that this may be of aid getting the Propeller 2 to be more widely adopted. I do not have a DE0 Nano so I can not do much on this (I am emulating a 4 core Prop2 in software on RISC OS very very slowly), and unfortunately I can not afford a DE0 Nano.
  • jmgjmg Posts: 15,175
    edited 2013-03-10 15:57
    Bill Henning wrote: »
    480Mbps is clearly impossible :)

    #1 did mention with a serialiser, and I think those were made, but are likely more expensive these days than a FT232H or FT313H
  • CircuitsoftCircuitsoft Posts: 1,166
    edited 2013-03-10 15:59
    Anyone know how to use ulpi?
  • Bill HenningBill Henning Posts: 6,445
    edited 2013-03-10 16:02
    Yes, you did mention them, and I counted on that when invoking the "impossible gets done" forum gods...

    Personally, I'd be quite happy with 1.5mbps for HID, and 12Mbps for serial and maybe bluetooth
    jmg wrote: »
    #1 did mention with a serialiser, and I think those were made, but are likely more expensive these days than a FT232H or FT313H
  • Cluso99Cluso99 Posts: 18,069
    edited 2013-03-10 21:04
    Brad and scanlime? did a LS USB using a few cogs on P1. The circuit is quite simple and I even did a small pcb to try it out. The P2 should do the LS simply, perhaps in a single cog multitasking. Of course it would be even better to do HS/FS? (the next higher speed). Forget 480Mbps.

    I had intended to get LS working porperly on the P1, but just not enough time. Maybe later this year.
  • CircuitsoftCircuitsoft Posts: 1,166
    edited 2013-03-11 10:45
    IIRC, Scanlime's host was full speed, not low speed (though it relied on the device doing retrys frequently)
  • Cluso99Cluso99 Posts: 18,069
    edited 2013-03-11 17:24
    Circuitsoft: Of course you are correct. IIRC there was no time to do CRCC checking either. All this shold be possible with P2.
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