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Single PS problem — Parallax Forums

Single PS problem

ArchiverArchiver Posts: 46,084
edited 2000-08-11 09:09 in General Discussion
It's my understanding that the ground of both supplies should be
connected to each other.

Rus

mhilt1@t... wrote:

> Can anyone tell me why i can only get things to work with my basic
> stamp when i use one common power supply. I first noticed this when
> i had built a simple dc motor control circuit, which i had drawing
> power from a separte power source than the basic stamp. I could
> never get it working. But when i connected the motors to the same
> power supply as the stamp, it worked fine. This was not so much a
> problem because the stamps 9v battery was accessible to the motors.
> But my latest adventure has me using two wireless rf modules made by
> Linx. Again, i was able to get the system to work perfectly when the
> componants are all supplied by the same battery, but when i put the
> transmitter( attached to my computers serial port) on its own 9v
> battery, and the reciever on the 9v battery of the stamp, it wouldn't
> work. This is very confusing to me. Like i said, i was able to get
> the system to transmit and recieve fine if the transmitter and
> reciever were powered by the same battery. Any help would be greatly
> appreciated. Thanks.
>
> matt

--
Rus Hardy
"Lucky Devil"
Keeper of the Bucky-n-Thrifty Flame
http://www.boneyardbargains.com/
"my mind wanders....I'm just along for the ride"

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2000-08-10 17:11
    Can anyone tell me why i can only get things to work with my basic
    stamp when i use one common power supply. I first noticed this when
    i had built a simple dc motor control circuit, which i had drawing
    power from a separte power source than the basic stamp. I could
    never get it working. But when i connected the motors to the same
    power supply as the stamp, it worked fine. This was not so much a
    problem because the stamps 9v battery was accessible to the motors.
    But my latest adventure has me using two wireless rf modules made by
    Linx. Again, i was able to get the system to work perfectly when the
    componants are all supplied by the same battery, but when i put the
    transmitter( attached to my computers serial port) on its own 9v
    battery, and the reciever on the 9v battery of the stamp, it wouldn't
    work. This is very confusing to me. Like i said, i was able to get
    the system to transmit and recieve fine if the transmitter and
    reciever were powered by the same battery. Any help would be greatly
    appreciated. Thanks.

    matt
  • ArchiverArchiver Posts: 46,084
    edited 2000-08-10 17:30
    It does work when the grouds are connected, but this does me no
    good. The reciever is on a robot, which i'm trying to communicate
    with via my computer wirelessly.
  • ArchiverArchiver Posts: 46,084
    edited 2000-08-10 20:37
    In a message dated 8/10/00 12:31:44 PM Eastern Daylight Time,
    mhilt1@t... writes:

    > It does work when the grouds are connected, but this does me no
    > good. The reciever is on a robot, which i'm trying to communicate
    > with via my computer wirelessly.
    Hi Matt,
    I'm using a similar type setup using the BS2 with linx hp modules and Motor Mind
    B. Are you using a stamp at the transmitter and a stamp at the receiver? My
    system uses a BS2 to send info to the the linx transmitter and a BS2 to receive
    the info from the linx receiver....

    Jerry
  • ArchiverArchiver Posts: 46,084
    edited 2000-08-10 21:25

    Original Message
    From: <mhilt1@t...>
    To: <basicstamps@egroups.com>
    Sent: Thursday, August 10, 2000 5:30 PM
    Subject: [noparse][[/noparse]basicstamps] Re: Single PS problem


    > It does work when the grouds are connected, but this does me no
    > good. The reciever is on a robot, which i'm trying to communicate
    > with via my computer wirelessly.
    >
    > I like the sound of your project, as I'm currently looking at a small
    robot which works almost the same as yours. Why is connecting the grounds no
    good to you, you said it works and both motors and BSII are running of
    diffrent supply voltages. Can you also email the address for the TX/RX pair
    that your using.

    Thanks, and good luck

    John.
    >
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2000-08-10 21:25

    Original Message
    From: <mhilt1@t...>
    To: <basicstamps@egroups.com>
    Sent: Thursday, August 10, 2000 5:30 PM
    Subject: [noparse][[/noparse]basicstamps] Re: Single PS problem


    > It does work when the grouds are connected, but this does me no
    > good. The reciever is on a robot, which i'm trying to communicate
    > with via my computer wirelessly.
    >
    > I like the sound of your project, as I'm currently looking at a small
    robot which works almost the same as yours. Why is connecting the grounds no
    good to you, you said it works and both motors and BSII are running of
    diffrent supply voltages. Can you also email the address for the TX/RX pair
    that your using.

    Thanks, and good luck

    John.
    >
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2000-08-11 01:58
    I was able to get the system working, it turned out i needed to have the tx
    connected to the computers ground, not just to the battery's cathode. I'm
    using linx transmitters and recievers, specifically the lc series. You can
    get them direct from their daughter company rfdigital at rfdigital.com. The
    problem with these is that they are surface mount devices. You can get the
    same product from a company called glolab, who uses the smd's in an easy to
    use pcb. For these goto www.glolab.com.
  • ArchiverArchiver Posts: 46,084
    edited 2000-08-11 02:02
    I was able to get the system working. It turns out i needed the transmitter
    ground connected to the serial ports ground, rather than just the 9v
    battery. Something about the logic devices, i don't know. My particular
    project uses a pc to transmit data to my robot. Or any serial device for
    that matter ( i have it working with my palm pilot too). What i meant by
    connecting the grounds being no good was that i need to have the robot free
    from the computer, or in this case the tx. I may have misinterpreted people
    when they said "connect the grounds". At any rate, its working. Thanks for
    your help.

    matt
  • ArchiverArchiver Posts: 46,084
    edited 2000-08-11 09:09
    At 09:02 PM 8/10/00, you wrote:
    >I was able to get the system working. It turns out i needed the transmitter
    >ground connected to the serial ports ground, rather than just the 9v
    >battery. Something about the logic devices, i don't know.

    Just for the record:

    Connect ALL grounds in any one (or multiple) system(s) [noparse][[/noparse]in one location]
    together, for a common ground plane/path. This not only provides the ( - )
    connectivity, but aides in implementing various sorts of supression systems
    (noise, EMI, cross-talk, etc) when coupled to the other onboard systems
    appropriately.

    > My particular
    >project uses a pc to transmit data to my robot. Or any serial device for
    >that matter ( i have it working with my palm pilot too). What i meant by
    >connecting the grounds being no good was that i need to have the robot free
    >from the computer, or in this case the tx. I may have misinterpreted people
    >when they said "connect the grounds". At any rate, its working. Thanks for
    >your help.
    >
    >matt

    Bruce Bates
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