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Power from USB port? — Parallax Forums

Power from USB port?

ArchiverArchiver Posts: 46,084
edited 2004-07-22 20:38 in General Discussion
Hi all

i have read about ie, phone chargers that steal power from the usb
ports on a pc. does anybody know a)what pins to use, b)what the
voltage is and c) what limit is there on power?

i am designing a serial data logger and although it will run
independant of the existing pc, i want to use the existing usb port
to power my project.
other than the stamp with a few minor components i also have a 4x20
LCD and would really like to be able to use the backlight function.

any ideas?

regards

steve

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2004-07-22 20:22
    Hi Steve,

    Pin 1 +5V
    Pin 4 Gnd
    (pin2 = Data-, pin3 = Data+)
    max 500mA (should be just enough for Stamp + Display + Backlight)

    You can check pin 1 and pin 4 with a multimeter


    Success,

    Klaus
    Original Message
    From: "steve" <steve2674@h...>
    To: <basicstamps@yahoogroups.com>
    Sent: Thursday, July 22, 2004 9:10 PM
    Subject: [noparse][[/noparse]basicstamps] Power from USB port?


    > Hi all
    >
    > i have read about ie, phone chargers that steal power from the usb
    > ports on a pc. does anybody know a)what pins to use, b)what the
    > voltage is and c) what limit is there on power?
    >
    > i am designing a serial data logger and although it will run
    > independant of the existing pc, i want to use the existing usb port
    > to power my project.
    > other than the stamp with a few minor components i also have a 4x20
    > LCD and would really like to be able to use the backlight function.
    >
    > any ideas?
    >
    > regards
    >
    > steve
    >
    >
    >
    > To UNSUBSCRIBE, just send mail to:
    > basicstamps-unsubscribe@yahoogroups.com
    > from the same email address that you subscribed. Text in the Subject and
    Body of the message will be ignored.
    >
    > Yahoo! Groups Links
    >
    >
    >
    >
    >
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2004-07-22 20:38
    Thanks Klaus, appreciated. [noparse]:)[/noparse]

    --- In basicstamps@yahoogroups.com, "K de Jong" <klaus0@x> wrote:
    > Hi Steve,
    >
    > Pin 1 +5V
    > Pin 4 Gnd
    > (pin2 = Data-, pin3 = Data+)
    > max 500mA (should be just enough for Stamp + Display + Backlight)
    >
    > You can check pin 1 and pin 4 with a multimeter
    >
    >
    > Success,
    >
    > Klaus
    >
    Original Message
    > From: "steve" <steve2674@h...>
    > To: <basicstamps@yahoogroups.com>
    > Sent: Thursday, July 22, 2004 9:10 PM
    > Subject: [noparse][[/noparse]basicstamps] Power from USB port?
    >
    >
    > > Hi all
    > >
    > > i have read about ie, phone chargers that steal power from the usb
    > > ports on a pc. does anybody know a)what pins to use, b)what the
    > > voltage is and c) what limit is there on power?
    > >
    > > i am designing a serial data logger and although it will run
    > > independant of the existing pc, i want to use the existing usb
    port
    > > to power my project.
    > > other than the stamp with a few minor components i also have a
    4x20
    > > LCD and would really like to be able to use the backlight
    function.
    > >
    > > any ideas?
    > >
    > > regards
    > >
    > > steve
    > >
    > >
    > >
    > > To UNSUBSCRIBE, just send mail to:
    > > basicstamps-unsubscribe@yahoogroups.com
    > > from the same email address that you subscribed. Text in the
    Subject and
    > Body of the message will be ignored.
    > >
    > > Yahoo! Groups Links
    > >
    > >
    > >
    > >
    > >
    > >
    > >
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