Shop OBEX P1 Docs P2 Docs Learn Events
Powering the Devantech SRF04 Ultrasonic Ranger — Parallax Forums

Powering the Devantech SRF04 Ultrasonic Ranger

ArchiverArchiver Posts: 46,084
edited 2002-06-11 03:10 in General Discussion
The documentation says that the power supply should be at least 50ma
to power both the Stamp II and the Devantech. If I power the Stamp
with a 9V transistor battery, will there be enough power to run the
Davantech off of the regulated 5v output of the Stamp? If not, how
do I power the Devantech? Does it need it's own power supply?

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2002-06-10 17:10
    I wrote an article about the devantech for N&V a few months ago. You CAN
    power the devantech from a 9v battery and the stamps internal regulator. You
    are pushing the limits of the stamp however, and you will have no power left
    over for anything else. I created a test device, with the stamp a devantech
    and a tiny speaker. I ran this from a 9V battery and carried it around the
    room listening to the output from the devantech.
    I do not recommend this for long term use, you are going to burn out the
    stamp's regulator eventually.
    You will need to use a small external power supply. Either onboard
    batteries such as 4 C cell batteries and a 5V regulator or an external 120V
    to 5V wall powerd regulator system. Radio shack has small referance
    notebooks on building power supplys as well as regulating a 4 cell battery
    pack to 5V.
    Good luck to you.
    -Kerry



    At 03:51 PM 6/10/02 -0000, you wrote:
    >The documentation says that the power supply should be at least 50ma
    >to power both the Stamp II and the Devantech. If I power the Stamp
    >with a 9V transistor battery, will there be enough power to run the
    >Davantech off of the regulated 5v output of the Stamp? If not, how
    >do I power the Devantech? Does it need it's own power supply?
    >
    >
    >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.
    >
    >
    >Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
    >
    >
    >

    Very respectfully, your obedient servant.
    Kerry
    Admin@M...
    WWW server hosting [url=Http://mntnweb.com]Http://mntnweb.com[/url]
    Kerry Barlow
    p.o. box 21
    kirkwood ny
    13795
    607-775-1132
  • ArchiverArchiver Posts: 46,084
    edited 2002-06-10 18:33
    Thanks for the quick response. I am trying to build a small robot
    that uses sonar for object avoidance. I don't have much space. I
    have a 9v transistor battery powering the stamp, and 4 AA batteries
    powering the servos for locomotion. I am using a Stamp II OEM which
    does have a larger votage regulator than the SMD type. It sounds
    like I need to have a third battery to power the Devantech? Since
    space is limited, I really don't want to do it (especially bulky C
    batteries!). Can I use some type of voltage regulator (like a 7805)
    and connect it to the 9V battery that powers the stamp? I am
    picturing one set of wires going from the battery to the stamp, and
    another set of wires going to the Davantech through a "7805". Would
    this work?

    Thanks,

    Steve

    --- In basicstamps@y..., Kerry Barlow <admin@m...> wrote:
    > I wrote an article about the devantech for N&V a few months ago.
    You CAN
    > power the devantech from a 9v battery and the stamps internal
    regulator. You
    > are pushing the limits of the stamp however, and you will have no
    power left
    > over for anything else. I created a test device, with the stamp a
    devantech
    > and a tiny speaker. I ran this from a 9V battery and carried it
    around the
    > room listening to the output from the devantech.
    > I do not recommend this for long term use, you are going to burn
    out the
    > stamp's regulator eventually.
    > You will need to use a small external power supply. Either onboard
    > batteries such as 4 C cell batteries and a 5V regulator or an
    external 120V
    > to 5V wall powerd regulator system. Radio shack has small referance
    > notebooks on building power supplys as well as regulating a 4 cell
    battery
    > pack to 5V.
    > Good luck to you.
    > -Kerry
    >
    >
    >
    > At 03:51 PM 6/10/02 -0000, you wrote:
    > >The documentation says that the power supply should be at least
    50ma
    > >to power both the Stamp II and the Devantech. If I power the
    Stamp
    > >with a 9V transistor battery, will there be enough power to run
    the
    > >Davantech off of the regulated 5v output of the Stamp? If not,
    how
    > >do I power the Devantech? Does it need it's own power supply?
    > >
    > >
    > >To UNSUBSCRIBE, just send mail to:
    > > basicstamps-unsubscribe@y...
    > >from the same email address that you subscribed. Text in the
    Subject and
    > Body of the message will be ignored.
    > >
    > >
    > >Your use of Yahoo! Groups is subject to
    http://docs.yahoo.com/info/terms/
    > >
    > >
    > >
    >
    > Very respectfully, your obedient servant.
    > Kerry
    > Admin@M...
    > WWW server hosting [url=Http://mntnweb.com]Http://mntnweb.com[/url]
    > Kerry Barlow
    > p.o. box 21
    > kirkwood ny
    > 13795
    > 607-775-1132
  • ArchiverArchiver Posts: 46,084
    edited 2002-06-10 23:07
    This is what I do for my robot. I have 4 AA batteries. I run them thru an
    LM2940 5 volt regulator. I then have enough power to run my stamp and
    devantech and some other small sensors. The servos I drive directly from the
    4 AA batteries at 6V. I tie the grounds of the servos and the ground of the
    regulator, and battery and stamp all together. Always tie all of your ground
    wires together.
    You cannot use a standard 7805 regulator because there is to much voltage
    drop within the 7805 series.
    go to national and order a free evaluation copy of the LM2940 regulator
    http://www.national.com/pf/LM/LM2940.html
    Good luck to you.
    -Kerry




    At 05:33 PM 6/10/02 -0000, you wrote:
    >Thanks for the quick response. I am trying to build a small robot
    >that uses sonar for object avoidance. I don't have much space. I
    >have a 9v transistor battery powering the stamp, and 4 AA batteries
    >powering the servos for locomotion. I am using a Stamp II OEM which
    >does have a larger votage regulator than the SMD type. It sounds
    >like I need to have a third battery to power the Devantech? Since
    >space is limited, I really don't want to do it (especially bulky C
    >batteries!). Can I use some type of voltage regulator (like a 7805)
    >and connect it to the 9V battery that powers the stamp? I am
    >picturing one set of wires going from the battery to the stamp, and
    >another set of wires going to the Davantech through a "7805". Would
    >this work?
    >
    >Thanks,
    >
    >Steve
    >
    >--- In basicstamps@y..., Kerry Barlow <admin@m...> wrote:
    >> I wrote an article about the devantech for N&V a few months ago.
    >You CAN
    >> power the devantech from a 9v battery and the stamps internal
    >regulator. You
    >> are pushing the limits of the stamp however, and you will have no
    >power left
    >> over for anything else. I created a test device, with the stamp a
    >devantech
    >> and a tiny speaker. I ran this from a 9V battery and carried it
    >around the
    >> room listening to the output from the devantech.
    >> I do not recommend this for long term use, you are going to burn
    >out the
    >> stamp's regulator eventually.
    >> You will need to use a small external power supply. Either onboard
    >> batteries such as 4 C cell batteries and a 5V regulator or an
    >external 120V
    >> to 5V wall powerd regulator system. Radio shack has small referance
    >> notebooks on building power supplys as well as regulating a 4 cell
    >battery
    >> pack to 5V.
    >> Good luck to you.
    >> -Kerry
    >>
    >>
    >>
    >> At 03:51 PM 6/10/02 -0000, you wrote:
    >> >The documentation says that the power supply should be at least
    >50ma
    >> >to power both the Stamp II and the Devantech. If I power the
    >Stamp
    >> >with a 9V transistor battery, will there be enough power to run
    >the
    >> >Davantech off of the regulated 5v output of the Stamp? If not,
    >how
    >> >do I power the Devantech? Does it need it's own power supply?
    >> >
    >> >
    >> >To UNSUBSCRIBE, just send mail to:
    >> > basicstamps-unsubscribe@y...
    >> >from the same email address that you subscribed. Text in the
    >Subject and
    >> Body of the message will be ignored.
    >> >
    >> >
    >> >Your use of Yahoo! Groups is subject to
    >http://docs.yahoo.com/info/terms/
    >> >
    >> >
    >> >
    >>
    >> Very respectfully, your obedient servant.
    >> Kerry
    >> Admin@M...
    >> WWW server hosting [url=Http://mntnweb.com]Http://mntnweb.com[/url]
    >> Kerry Barlow
    >> p.o. box 21
    >> kirkwood ny
    >> 13795
    >> 607-775-1132
    >
    >
    >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.
    >
    >
    >Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
    >
    >
    >

    Very respectfully, your obedient servant.
    Kerry
    Admin@M...
    WWW server hosting [url=Http://mntnweb.com]Http://mntnweb.com[/url]
    Kerry Barlow
    p.o. box 21
    kirkwood ny
    13795
    607-775-1132
  • ArchiverArchiver Posts: 46,084
    edited 2002-06-10 23:29
    Thanks so much!!!! You gave me the specifics I was looking for (and
    in terms that I could understand!!!)

    Again, thanks so much!!!

    Steve
  • ArchiverArchiver Posts: 46,084
    edited 2002-06-11 03:10
    >I wrote an article about the devantech for N&V a few months ago. You CAN
    >power the devantech from a 9v battery and the stamps internal regulator. You
    >are pushing the limits of the stamp however, and you will have no power left
    >over for anything else. I created a test device, with the stamp a devantech
    >and a tiny speaker. I ran this from a 9V battery and carried it around the
    >room listening to the output from the devantech.

    I have successfully run 8 SRF04's simultaneously on the same stamp
    (the final code actually pulsed 4 at a time to eliminate crosstalk
    issues). The stamp board was running off 12V shared with the IFI
    robot controller, using Lithium AA cels.

    Never bothered to check whether or not this would stress the Stamp,
    it worked quite reliably, even with a 9V alkaline battery. The
    SRF04's would tend to die a bit more often than I'd like but that was
    probably due to the harsh environment (a battlebot).

    'Course, I could be wrong, I'm a software geek, I wouldn't know a
    milliamp if it bit me in the behind.

    Best
    R
Sign In or Register to comment.