GPS receivers

This page has notes on GPS receivers that I am interested in. I own a few of them and list a few others for comparison purposes.

I list both receivers integrated into systems like the Garmin eMap handheld and modules such as the Trimble Lassen SQ.

You can get the bare modules or you can use modules that have been built up into GPS hockey pucks. (Some people call them GPS mice.) For example, you can get a Garmin 25 module and wire it directly to the low voltage serial port on a PIC processor or you can get a Garmin GPS-18 hockey puck and plug it into a USB port.

For hobbyists probably the best place to get the bare modules is [Spark Fun Electronics], they have a bunch of other modules that I don't list here yet.

I got the modules I have currently on eBay.

Since I originally wrote this page I have obtained an Emtac BT-338 from Tigerdirect for about $50 and a Wintec WBT-100, $95 from Semson. Both of these have bluetooth. The Wintec has WAAS, a compass, bluetooth, and USB.

Semson is a good place to get GPS stuff.

Garmin

Garmin OEM information

Model	Accuracy	Channels	Price	Comments
eTrex Vista	10m/3m WAAS	12	$200-300	Handheld, USB but no serial (so no RTCM) or antenna ports. Just got an HcX. (9/07)
eMap	15m/2m RTCM	12	$60 or so on Ebay	Handheld, accepts RTCM for DGPS. Apparently a bad choice for Rinex software DISCONTINUED
GPS 10	15m/3m WAAS	12	$250	bluetooth module
GPS 15	15m	12	about $50	bare module, several models. Tiny successor to GPS-25
GPS 16 LVS (3.3-6V), 16 HVS (6-40V), 16 A (8-40V)	15m / <3m WAAS / 3-5 USCG RTCM	12 channel		2 serial ports, deck mount
GPS 17			$200	basically the same as a GPS 16 but in a white, pole mount case
GPS 18	15m / 3m WAAS	12	$130	CMOS serial or RS232 or USB hockey puck
GPS 25-LVC (3.6-6V), -LVS(3.6-6V RS232), -HVS(6-40V RS232)	15m / 5m DGPS	?		bare module; capable of raw data output (pseudorange and phase) [1] DISCONTINUED
GPS 35 / 36	15m / 5m DGPS	?		35 = mouse style, 36 = pole mount

The GPS 17 is designed for marine applications but is sometimes pressed into service in backpack style data collectors.

Trimble

GPS modules

Model	Accuracy	Channels	Connectors		Price (est)	Comments
Pathfinder Pocket	10m/2m DGPS	8	2 RS232 via one DB9, SMB 3.3v, power		$500	includes an external antenna.
M-Loc	10m (no DGPS)	12		3.3v 35mW(68mW) 25 x 25 x 6.9 mm	$45	FirstGPS software runs on host processor
Lassen SQ	6-9m,no DGPS	8	8 pin header, H-FL-R-SMT	3.3v/100mW 26x26x6 mm, 5.7g	$45 (use IQ instead!)	Use w/RF transition cable
Lassen IQ	5-8m,no DGPS	12	8 pin header, H-FL-R-SMT	3.3v/85mW 26x26x6 mm, 5.7g	$50	Updated more accurate version of SQ. Purchase from SparkFun
Ace II	25m/2m DGPS	8	8 pin (2 CMOS TTL serial) SMB 5v/25mA	5v / 95mA / .47W 82.6 x 46.5 x 11.5 mm	cheap	Discontinued but I got one from eBay for $10
Ace III	25m/2m DGPS	8	8 pin (2 CMOS TTL serial) SMB 5v/25mA	5v / 95mA / .47W 82.6 x 46.5 x 11.5 mm	$80
Lassen SK-8	25m/2m DGPS	8	8 pin (2 CMOS TTL serial) SMB 5v/25mA		$	Discontinued; use SKII
Lassen SKII	25m/2m DGPS	8	8 pin (2 CMOS TTL serial) SMB 5v/25mA	5V / 95mA(120mA)/ .47W(.60W)	$80
Lassen LP	25m/2m DGPS	8	2 serial and power via 8 pin header, MCX/3.3v 12mA	3.3V / 55mA(67mA)/ .182W(.221W) 66.167 x 31.75 x 12	$55	Low power; can be programmed to power up/down on schedule

Style	Gain	Connector	Price
Micropatch	26dB	5m cable with MCX	$17
Hardmount micropatch	26dB	TNC	$
Bullet	35dB	22m cable with SMB adapter	$

DIY USB Lassen SQ

ToppTec -- purveyors of Trimble OEM modules

Delorme

http://www.delorme.com/

Consumer grade; Earthmates are WAAS enabled but the older Tripmates are cheap on eBay if you just need a NMEA GPS source.

Model	Accuracy	Channels	Price	Comments
Tripmate	15m?	12	$20-30 on eBay	rs232 (discontinued)
Earthmate	WAAS	12	$100	USB
Blue logger	WAAS	12	$150	bluetooth enabled

Other links

Leica
Thales and Magellan
U-blox sells mostly Sony modules.