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Digital to Analog Converter that will convert a range of -5 to +5 volts DC — Parallax Forums

Digital to Analog Converter that will convert a range of -5 to +5 volts DC

dodgerdodger Posts: 37
edited 2008-10-30 21:42 in BASIC Stamp
I would like to interface an Analog Gyro to my BS2.· The outputs of the Gyros can be a positive or negaive DC voltage depending on the direciton of angular acceleration.·

I am thinking that I should use an analog to digital converter to interface with the BS2.· Is this the best method?

I have looked at some of the ADC sold by Parallax and the specs all say 0 to 5 volts, will these work?


Any help would be appreciated.
·Link to Gyros.
·http://media.digikey.com/pdf/Data%20Sheets/Analog%20Devices%20PDFs/ADXRS401.pdf
Thanks

Post Edited (dodger) : 10/17/2008 11:56:38 PM GMT

Comments

  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2008-10-15 05:23
    This could be very easy, or more difficult, depending on the analog output impedance of the gyro. Do you happen to know what it is? Also, since the gyro can output -5V, can we assume that you have a negative supply available that you can tap?

    -Phil
  • $WMc%$WMc% Posts: 1,884
    edited 2008-10-16 01:26
    dodger

    I'm on the same band wagon as Mr.Pilgrim;need a little more info. on the Gyros.If you don't have any, Can you split the common conection to make two 0 to 5+ signals???...You could also look @ it as a 0 to 10 volt singnal + or - !!!!!


    $WMc%___________out__
  • GeekgirlGeekgirl Posts: 50
    edited 2008-10-16 02:47
    ·· Look at using the MAX1270, as it is capable of accepting your +/- 5volt range.


    · http://www.parallax.com/Portals/0/Downloads/docs/prod/compshop/max1270.pdf

    ···· Darlene
  • $WMc%$WMc% Posts: 1,884
    edited 2008-10-18 01:53
    ·Hello dodger

    ········ I got your PM and I looked @ the link.· I thought You where talking about motor drivin gyros. I've never worked w/ the soild state model You have. The Doc. in the link refered to "CORIOLIS FORCE". I have worked w/ a few Coriolis Meters in fluid proccess. You may find some code snippets in this search.....Try lookin in LimeSlurry or Juice (like orange or grape)

    ·· P.S.· Have You looked @ the Hitachi HM55B compass Module (#29123)or H48C#(28026) TRI-Axis Accelerometer?. Memsic also has A Dual-Axis Ver. Parallax p# (28017)....All of these have some sample code to get started w/, And will do the same thing A gyro does



    ·············································· $WMc%______out________________
  • Carl HayesCarl Hayes Posts: 841
    edited 2008-10-26 00:57
    Take two equal resistors. Put them in series. Tie one end to +5 volts. Tie the other end to your signal that vaies from -5 to +5. The middle, where the two resistors are connected, will vary from 0 to +5. Feed this to your ADC tht only handles 0 to +5. Not too tough.

    -- Carl
  • dodgerdodger Posts: 37
    edited 2008-10-30 17:32
    That sounds simple enough, but I still need to know that it once was a negative value.· Any suggestions?

    Thanks
  • Carl HayesCarl Hayes Posts: 841
    edited 2008-10-30 21:42
    Bless your heart, if it's below +2.5 at the point between the two resistors, it must have been below 0 at the bottom end.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    · -- Carl, nn5i
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