I'll get started on this if anyone's interested, and make updates as necessary if it's well received. This isn't meant to be a be-all-end-all comparison, but rather a guide for shoppers like me who had no direction to look when shopping for a receiver.
Things to look for:
- miniUSB charging
- size/weight
- battery life
- Replaceable battery
- GPS logging capabilities
MiniUSB charging is an obvious benefit for BB users, because it can share chargers w/ the BB (tried and tested).
Size and weight is an obvious concern, but most packages are optimized one way or another (either super low weight/small size at the expense of battery life, or vice versa). Some are longer, but thinner, etc etc.
Battery life is addressed better in the chipset comparison below.
Replaceable batteries are pretty important in my opinion, unless you want the iPod syndrome, which means you'll be left with a brick once the battery cycles to death.
GPS logging is a neat feature to have, which basically creates a large log of your positions over time (or change in position, depending on how you set it), and stores it in memory to be downloaded later. It doesn't interface w/ anything on the Blackberry, but if you're stalking someone (legally of course), it'll give you pinpoint accuracy of where someone's been. Be sure to check the memory size offered (8 MB will get you around 50,000 waypoints).
There are basically 4 current competitors in the ultra-low power consumption GPS receiver market. These chipsets are:
MTK, the
SiRFstarIII, the
uBlox Antaris 4, and the
NemeriX NJ-2020. Chipsets are rated by sensitivity, where the MTK is rated at -158 dBm, the SiRFstarIII is rated at -159 dBm, the uBlox Antaris is rated at -158 dBm, and NemeriX comes in rated at -152 dBm or better. All in all, these mean pretty much nothing. There are also older iterations of these chipsets (i.e. SiRFstarII, etc), but all the new ones seem to capture the benefits of the old ones without any drawbacks. They are all similarly priced as well.
To throw out blanket statements:
MTK
This is MTK's first GPS chipset, and it appears to be an instant hit. The MTK based units are currently the
*most accurate* in driving speed conditions (results unverified by me personally, but verified by many reviewers on the Internet). They are also more suited for urban applications because they are less susceptible to positioning errors due to reflected signals off buildings and such. They also come out as the most sensitive units, acquiring satellites where no others do at times. The MTK units are also surprisingly frugal with power, with some units like the Qstarz BT-Q818 achieving an astounding battery life of 32 hours on a 1000 mAh battery.
More popular MTK offerings include:
Freedom Keychain GPS 2000
Transystem i-Blue 737
Transystem i-Blue 747 (same as 737 but w/ GPS logging)
Transystem i-Blue 757 (solar powered! but clunky)
Qstarz BT-Q818
SiRFstarIII
SiRFstar has been the industry leader debuting most recently their 3rd generation of chips. Before MTK arrived, they led the way in terms of accuracy. They still do offer better accuracy for walking conditions than the MTK, should you ever feel the need to track your walks through town. They have the most widely used chipset, being the OEM provider for Holux, Globalsat (who builds receivers for Telenav), and others. Their chipsets aren't as frugal as MTK's, with around a 8-10 hour battery life for a 1000 mAh battery (some units do come with extra large batteries to compensate, at the expense of size). A low power version of the chipset has been developed that supposedly sacrifices nothing for lower power consumption except for 5 Hz sampling rate (which is excessive for mapping purposes). Since they have been industry leaders, many have developed free 3rd party software for Palm/Pocket PC's that offer tweaks and support some more advanced features of the chipset (not that I see any of us BB users needing that).
More popular SiRFstarIII offerings include:
Holux GPslim 236 (almost an industry standard)
Holux GPslim 240 (USB thumbdrive sized, at the expense of battery life)
Globalsat BT-338
Globalsat BT-359
OnCourse Edition 2 (same as Globalsat BT-359)
Telenav GPS Receiver (same as Globalsat BT-359)
Royaltek RBT-2010
Pharos PT250
uBlox Antaris 4
On par with the SiRFstarIII chipset is the uBlox Antaris 4, which provides similar accuracy, but perhaps not as high sensitivity as the others. They also offer "powerful" tweaking software. I'll post more if I find more.
More popular uBlox offerings include:
Socket uBlox SuperSense
Wintec WBT-201
NemeriX NJ-2020
I haven't found many units implementing this chipset, thus there's few reviews to read up on, but what I've gathered so far is it has high sensitivity (can pickup weak signals that the uBlox can't) and is on par w/ the SiRFstarIII in terms of accuracy.
More popular NemeriX offerings include:
i-Blue PS-3200
So what should I buy?!?!
After sifting through all the reviews and whatnot for half a day, I plunked down my money for an i-Blue 747. It features an MTK chipset, with logging capabilities. I have no need for the tweakability offered by the SiRFstarIII's, and liked the proposition of very long battery life, GPS capability (with 16 MB so up to 100,000 waypoints), great urban performance, and great accuracy. So far, its worked great with the BB. Your priorities might be different than mine, so I can't tell you what to do except to do some reading if this wasn't sufficient. Also, each implementation by each manufacturer may affect the performance of each chipset one way or another. So *all* MTKs might not be superior to SiRFstarIII's, etc. Read the reviews if you're so interested.
Sites to look at:
Reviews:
G p s P a s S i o n
Pocket GPS World
Manufacturers:
Freedom Input GPS & Keyboards
Transystem Inc.
Qstarz!
HOLUX
USGlobalSat
Pharos GPS
TeleNav GPS Receiver
u-blox: Home
RoyalTek
Haicom Electronics CORP.
Buying:
buy GPS Now
Semsons
eBay
GUIDE: Bluetooth GPS Pucks
GPS for BB7290
