general GPS advice required

Closed Thread
Results 1 to 9 of 9

Hybrid View

  1. - 6th September 2010, 16:04 #1
    ScaleRobotics's Avatar
    ScaleRobotics
    ScaleRobotics is offline Prolific Poster
    Join Date
    Feb 2006
    Location
    Gilroy, CA
    Posts
    1,530

    Did you find this post helpful? Yes | No

    Default

    Well, I can't read the last attachment, but if you are reading the data out of the unit, I would say you have the serial communication part down.

    After reading this: http://eshop1.chem.buffalo.edu/600M-GPS.html it seems to take amplified as well as non amplified antennas. So that's probably not it. How about power supply? Are you giving it enough juice?

    This is supposed to be a similar model and pinout, but the board is different.
    http://images.weirdstuff.com/thumb/rockwellGPS.pdf

    You might try giving the pre-amp pin 5 volts, if you are not already. This is supposed to give the amplified antenna, its power source. Also, note the frozen start they refer to. They don't even tell you how long it will take out of the box, with old ephemeris data. So be prepared to wait a while to first fix.

    Walter
    Last edited by ScaleRobotics; - 6th September 2010 at 16:10.
    http://www.scalerobotics.com
  2. - 6th September 2010, 20:41 #2
    comwarrior's Avatar
    comwarrior
    comwarrior is offline Member
    Join Date
    Jun 2009
    Posts
    251

    Did you find this post helpful? Yes | No

    Default

    The preamp has been tried powered and unpowered... according to the datasheet for the antenna's they require 3.3V or 5V...

    The 5V supply is from a 5V regulator LM7805CV and that is fed from a 12V 16AH lead acid battery...
    The unit is currently pulling ~250mA including charging a 3.6V LiPOL @ ~10mA (SRAM and RTC battery backup)

    Comms to and from the unit seems ok.

    The last attachment is a PDF datasheet for the antenna.

    I've left the unit on over night ~ 8 hours but the manual says 15 mins...

    I did notice the receiver is TU00 and the antenna's are for TU30 which i'll be surprised if it's incompatible...
    I'm going to try the other board (i baught two identical) just to see if it's a board fault...
    If that fails i'm going to see if i can make a passive antenna...
  3. - 23rd October 2010, 18:40 #3
    Regenpak's Avatar
    Regenpak Guest

    Did you find this post helpful? Yes | No

    Default

    FWIW- I have the same type of unit. I hooked it up to an active antenna and while it powered the patch antenna it only output the GPGGA with all zeroes. It did see satellites but it refused to acquire a fix. Then I swapped the patch antenna for another one liberated from a USB GPS receiver (Navtech or something, lost the enclosure) and within 15 minutes, as promised, I had a fix with proper GPGGA and GPVTG data.

    You may want to check the decrease in drawn current, these patch antennas need about 10 mA at 5 volts to work. Just unplug the MCX connector.

    Good luck!
« Previous Thread | Next Thread »

Members who have read this thread : 0

You do not have permission to view the list of names.

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts

Forum Rules