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Propstick USB — Parallax Forums

Propstick USB

Ole Man EarlOle Man Earl Posts: 262
edited 2009-06-30 03:25 in Propeller 1
Can you take the 5VDC from the usb port to power the prop from the usb? I think there is enough current. Just takes one jumper wire.
Earl

Comments

  • PainlessPainless Posts: 69
    edited 2009-06-30 02:57
    I've successfully use the USB power to run my PropRPM board.
  • DogPDogP Posts: 168
    edited 2009-06-30 03:25
    You can... I rigged my USB proto board to power from USB, although I had to remove the 5V regulator (of course) and associated caps (without removing the caps, it'd disconnect and reconnect the USB when I turned it on). Of course you have to be careful not to exceed the current (or short something) as you could blow the USB port on your computer (so a powered USB hub may be a smart idea). My application is known and won't change, so once I determined the specs and realized it could be done from USB, I made the mod, but I wouldn't do it for a proto board that I planned on doing lots of prototyping on.

    Also note the specs on current before initialization and after initialization... not sure if anything will be damaged, but IIRC you're supposed to be limited to 100mA until negotiating as a high current device, which you're then permitted to draw 500mA (that's just from memory... you should read the details, although I don't think it's strictly followed).

    DogP
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