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PMB-688 SiRFstarIII Chipset — Parallax Forums

PMB-688 SiRFstarIII Chipset

fireman508fireman508 Posts: 19
edited 2012-01-03 04:58 in Accessories
Does anyone know which SiRFstarIII chipset is used in the PMB-688 GPS module? Thanks!

Comments

  • PublisonPublison Posts: 12,366
    edited 2012-01-02 15:39
    Probably a question to ask Parallax Tech Support.

    support@parallax.com
  • Ken GraceyKen Gracey Posts: 7,392
    edited 2012-01-02 16:06
    Hey fireman508,

    As a fairly new poster to the forums we welcome you!

    We purchase these modules from Polstar in Taipei. I collected up all the data we have and here's what I came up with:

    Polstar show the PMB-688 specs here http://www.polstargps.com/Polstar_GPSproducts_PMB688.html
    The Parallax datasheet is http://www.parallax.com/Portals/0/Downloads/docs/prod/sens/PMB-688_Specification_V0.1.pdf

    I checked our internal network for additional documentation about the SiRFstarIII chipset and found nothing else.

    I don't know the differences between the SiRFstarIII chipsets, but I'm wondering if you could determine it by looking at the specs (i.e., number of satellites, time for soft-start, etc).

    We are in constant communication with Polstar so I'll write them a message and ask the question.

    Ken Gracey
  • fireman508fireman508 Posts: 19
    edited 2012-01-03 04:01
    Ken Gracey wrote: »
    Hey fireman508,

    As a fairly new poster to the forums we welcome you!

    We purchase these modules from Polstar in Taipei. I collected up all the data we have and here's what I came up with:

    Polstar show the PMB-688 specs here http://www.polstargps.com/Polstar_GPSproducts_PMB688.html
    The Parallax datasheet is http://www.parallax.com/Portals/0/Downloads/docs/prod/sens/PMB-688_Specification_V0.1.pdf

    I checked our internal network for additional documentation about the SiRFstarIII chipset and found nothing else.

    I don't know the differences between the SiRFstarIII chipsets, but I'm wondering if you could determine it by looking at the specs (i.e., number of satellites, time for soft-start, etc).

    We are in constant communication with Polstar so I'll write them a message and ask the question.

    Ken Gracey

    Hi Ken,

    Unfortunately, comparing the 3 different SiRFstarIII Chips found on the manufacturers website (http://www.csr.com/products/platform/location) to the PMB-688 specs didn't reveal any useful clues...they are all fairly similar...

    Thank you very much for contacting Polstar on my behalf . Much appreciated!

    Some background info if you're curious as to why I'm inquiring which Chipset is used:

    I'm constructing a weather balloon to take high altitude photos and temperature data and I'm using the PMB-688 to track the balloon during its journey (I've already managed to loose my first balloon due to a less than adequate tracking system). The problem I've encountered is the altitude limit of 60K feet placed on all publicly available GPS modules. However, other balloonists have reported that a specific SiRFstarIII chipset, which I hope is the one used in the PMB-688, does not have this limit if the velocity is below the speed restriction.

    Thanks again for your help,
    -Matt
  • Jorge PJorge P Posts: 385
    edited 2012-01-03 04:58
    I posted on a different thread about SirfStar, http://forums.parallax.com/showthread.php?133896-GPS-and-RF-Problem&p=1030999&viewfull=1#post1030999

    If you use SirfDemo, it will tell you what version of software you are using. With that and the "SiRF Binary Protocol Reference Manual" you can gather what chipset you have! This is because only certain versions of software only work on certain chipsets.

    Hope this is helpful!
    Jorge
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