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Distance & Speed Measurer, Wireless — Parallax Forums

Distance & Speed Measurer, Wireless

ArchiverArchiver Posts: 46,084
edited 2000-11-21 22:10 in General Discussion
I have an need for a device that does the following:

Counts a pulse (from a disk that has ~20 magnets)
Processes the info (pulses to inches, pulses to mph)
If mph = X then close relay
Transmit data to another stamp (using the rf modules from parallax)

I know that this is all possible, but I have never used a stamp
before, and have only a little electronics knowledge.

Your help is appreciated,

Marlin Schrock

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2000-11-21 12:32
    This is very straighforward for a Stamp. The only limitations will be
    speed and time accuracy. Refer Stamp manual for COUNT command. You also
    will need a Hall effec magnetic sensor. Remember also integer 16 bit
    math of Stamp. If you have the Stamp, all the parts and time go ahead.We
    will help if you ask.
    ACJacques
    ih_660@y... wrote:
    >
    > I have an need for a device that does the following:
    >
    > Counts a pulse (from a disk that has ~20 magnets)
    > Processes the info (pulses to inches, pulses to mph)
    > If mph = X then close relay
    > Transmit data to another stamp (using the rf modules from parallax)
    >
    > I know that this is all possible, but I have never used a stamp
    > before, and have only a little electronics knowledge.
    >
    > Your help is appreciated,
    >
    > Marlin Schrock
  • ArchiverArchiver Posts: 46,084
    edited 2000-11-21 13:11
    At 12:10 PM 11/21/2000 +0000, you wrote:
    Hi Marlin -
    I have an need for a device that does thefollowing:

    Counts a pulse (from a disk that has ~20 magnets)
    Processes the info (pulses to inches, pulses to mph)


    Essentially you are describing a Hall Effect sensor. One source for suchsensors is Allegro Micro at [noparse]/noparse][url=http://www.allegro-micro.com/]http://www.allegro-micro.com[/url. You might check their Selector Guide of Sensors at:

    ·············· [noparse][[/noparse] http://www.allegromicro.com/selguide/hed1.htm ]
    If mph = X then close relay
    Transmit data to another stamp (using the rf modules from parallax)


    Allegro makes a specific sensor/driver for activating solenoids or lamps. Per their documentation of the chip:


    [font=Arial, Helvetica]The UGQ5140K unipolar Hall effect switch is a monolithic integrated circuit designed for magnetic actuation of low-power incandescent lamps or inductive loads such as relays or solenoids. Included on chip is a Darlington power output that is capable of continuously sinking in excess of 300 mA. Internal protection circuitry limits surge (lamp turn-ON) or fault currents to approximately 900 mA.
    A sensitive magnetic threshold allows the device to be used in con-junction with inexpensive magnets or in applications that require relatively large operating distances.

    [/font]
    I know that this is all possible, but I have never used a stamp
    before, and have only a little electronics knowledge.

    Your help is appreciated,

    Just shout if you need more assistance. I trust you have the Stamp PBASIC Manual and the Stamp Editor (Windows and Mac versions are available for free). If not they can be downloaded for the Parallax web site [noparse][[/noparse] http://www.parallaxinc.com ] in the Documentation Section.

    Marlin Schrock


    Regards,

    Bruce Bates
  • ArchiverArchiver Posts: 46,084
    edited 2000-11-21 13:30
    To obtain the speed:
    count the pulses in 1 second and divide by 20, you will get rotations per
    second.
    multiply by 6.28 to get rad/s.
    v=w * r
    v=linear velocity (m/s)
    w=angular velocity (rad/s)
    r=radius (m)
    you will get m/s.
    multiply by 2.2369 to convert to mph.
    be sure that its sensor supports the maximum rotation and that doesn't have
    skidding.

    sds
    Fabiano


    Original Message
    From: <ih_660@y...>
    To: <basicstamps@egroups.com>
    Sent: Tuesday, November 21, 2000 10:10 AM
    Subject: [noparse][[/noparse]basicstamps] Distance & Speed Measurer, Wireless


    > I have an need for a device that does the following:
    >
    > Counts a pulse (from a disk that has ~20 magnets)
    > Processes the info (pulses to inches, pulses to mph)
    > If mph = X then close relay
    > Transmit data to another stamp (using the rf modules from parallax)
    >
    > I know that this is all possible, but I have never used a stamp
    > before, and have only a little electronics knowledge.
    >
    > Your help is appreciated,
    >
    > Marlin Schrock
    >
    >
    >
    >
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2000-11-21 22:10
    Hi.

    I have been trying to come up with a similar solution for counting pulses.
    Has anyone tried to use the Hamamatsu P5587 Photoreflector with the Basic
    Stamp? (I have a bunch of these and have seen them used on the Rug Warrior
    Pro robots).

    What I have so far is printed encoder wheels that have black strips on it
    with a white background attached to each wheel.


    Original Message
    From: "Fabiano Bovo" <go_robot@t...>
    To: <basicstamps@egroups.com>
    Sent: Tuesday, November 21, 2000 8:30 AM
    Subject: Re: [noparse][[/noparse]basicstamps] Distance & Speed Measurer, Wireless


    > To obtain the speed:
    > count the pulses in 1 second and divide by 20, you will get rotations per
    > second.
    > multiply by 6.28 to get rad/s.
    > v=w * r
    > v=linear velocity (m/s)
    > w=angular velocity (rad/s)
    > r=radius (m)
    > you will get m/s.
    > multiply by 2.2369 to convert to mph.
    > be sure that its sensor supports the maximum rotation and that doesn't
    have
    > skidding.
    >
    > sds
    > Fabiano
    >
    >
    >
    Original Message
    > From: <ih_660@y...>
    > To: <basicstamps@egroups.com>
    > Sent: Tuesday, November 21, 2000 10:10 AM
    > Subject: [noparse][[/noparse]basicstamps] Distance & Speed Measurer, Wireless
    >
    >
    > > I have an need for a device that does the following:
    > >
    > > Counts a pulse (from a disk that has ~20 magnets)
    > > Processes the info (pulses to inches, pulses to mph)
    > > If mph = X then close relay
    > > Transmit data to another stamp (using the rf modules from parallax)
    > >
    > > I know that this is all possible, but I have never used a stamp
    > > before, and have only a little electronics knowledge.
    > >
    > > Your help is appreciated,
    > >
    > > Marlin Schrock
    > >
    > >
    > >
    > >
    > >
    > >
    >
    >
    >
    >
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