Tor

Member Since: July 17, 2011

Country: United States

  • Product RTL-09891 | about 2 years ago

    The “track up to 66 satellites at a time” claim is bogus - that’s not what all those channels are for.

    When you cold-start the device it doesn’t know the time, it doesn’t know where on the earth it is, it doesn’t know the ephemeris data of any of the satellites, and it doesn’t know the doppler shift of the satellites and it doesn’t know the doppler shift of you (you may be moving in a vehicle). So it starts to scan. The way to do that is to listen to some frequencies for a while, then shift frequencies and listen for more. Until it finds at least one satellite. Then it has to wait for the almanac data to come around (imprecise ephemeris data for all the satellites) which only happens occasionally and may take half a minute to receive all of it).

    All of this goes much faster if you can listen to a great many channels at the time. A 12-channel GPS receiver will listen with 12 channels, then change frequencies and listen to another set of frequencies. A 66-channel, or even 48- or 32-channel receiver can search, find, and acquire almanac data (which is used to then find each individual satellite and acquire its satellite-specific precise ephemeris data) much quicker. That’s why these megamulti-channel GPS receivers can basically guarantee to go from cold-start to lock in < 35 seconds, while an old 12-channel receiver as the SiRF Star II could take much longer, and wouldn’t lock at all if you’re not standing still while searching (it doesn’t have enough channels to afford dedicating some of them to be set up for doppler shifts). The newer SiRF Star III has many more channels than my old Star II. Likewise the MTK chipset I’m using now, it doesn’t need you to stand still while searching - it locks fine even when flying at high altitude inside a 747. In fact the 66 channels of this LS20031 seems a bit of overkill when compared to how well the 30-48-channel receivers work.

  • Product POR-09803 | about 3 years ago

    The 1100mAh battery is a bit on the small side.. seems like there should be room enough for something larger. My Pandora handheld (size like a small DS) has a 4000mAh battery. As far as I know prices are basically the same for small vs. larger li-poly batteries. Having to charge daily is slightly on the painful side.

  • Product POR-09803 | about 3 years ago

    This.. is a must-have. But the price+shipping to here+VAT+charges will make it rather expensive I fear.. so there’ll be a period of dragging of feet until I convince myself to buy (and/or waiting for the US dollar exchange rate to take a deep dive, as it does occasionally).

  • Product TOL-10806 | about 3 years ago

    Sparkfun: Could you clarify this, please? The pictures indeed seems to be of a 5.7" display scope, while the 1102CML is supposed to be a 7" scope (and the pictures on the Atten site looks quite different).

  • Product PRT-09720 | about 3 years ago

    The doghouse is very well made, but there’s a huge oversight: There’s no cutout for the serial port. Presumably it’s overlooked because it’s an IDC header and looks like some ‘internal’ test connector like the jtag (it’s only an IDC because there’s no room for a full-size serial port connector). It still means I can’t work with the Beagleboard in the doghouse until I’ve got another hole made (which I’m no good at making, that’s why I bought a pre-made enclosure..)
    I don’t at all regret buying it (using the board just on the foot section without the cover is much better than nothing), but I wish the enclosure designer had actually been a Beagleboard user.. then this wouldn’t have happened.

  • Product TOL-08938 | about 3 years ago

    The LA1034 looks very nice, but it appears to have only Windows software support, no Linux or Mac. I don’t have any Windows computers and I doubt it’s a good idea to try to run that kind of thing under Wine. Tried the 64-bit Linux version of the Salea Logic sw in demo mode, and it worked fine. Would have been nice to have a higher-spec'ed tool like the LA1034, but without software support, no deal.
    Edit: Added ‘LA1034’ to make clear what I was commenting on.

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