Hammerhead/Protocol - Revision history

DolfjeBot1: Replacing 'Freerunner' with 'FreeRunner'

2008-08-31T12:39:28Z

Replacing 'Freerunner' with 'FreeRunner'

2008-08-17T06:19:52Z

2008-08-15T20:28:18Z

Added intro

2008-04-30T01:46:28Z

Link to an old schwartz log.

2007-10-28T11:11:54Z

point to sources, not binary

2007-10-28T11:09:20Z

2007-10-28T11:08:19Z

Move most interesting info to the fromt

2007-10-28T11:06:52Z

removed obsolete info. Sphyrna project decoded hammerhead better.

2007-09-20T05:33:42Z

Added a link to a library of useful GPS algorithms

2007-08-31T01:57:28Z

Added a link to my 'satscan' program

← Older revision		Revision as of 12:39, 31 August 2008
Line 1:		Line 1:
−	Hammerhead is the GPS receiver chip used in the Neo 1973. The only way currently to use it is via a closed-source binary program. This page describes efforts to write an open source driver. (Mostly abandoned since the release of the Neo ~~Freerunner~~ which uses a different chipset)	+	Hammerhead is the GPS receiver chip used in the Neo 1973. The only way currently to use it is via a closed-source binary program. This page describes efforts to write an open source driver. (Mostly abandoned since the release of the Neo FreeRunner which uses a different chipset)

	== Repository ==		== Repository ==

← Older revision		Revision as of 06:19, 17 August 2008
Line 1:		Line 1:
−	Hammerhead is the GPS receiver chip used in the Neo 1973. The only way currently to use it is via a closed-source binary program. This page describes efforts to write an open source driver. (Mostly abandoned since the release of the Neo Freerunner which uses a different ~~chipsset~~)	+	Hammerhead is the GPS receiver chip used in the Neo 1973. The only way currently to use it is via a closed-source binary program. This page describes efforts to write an open source driver. (Mostly abandoned since the release of the Neo Freerunner which uses a different chipset)

	== Repository ==		== Repository ==

← Older revision		Revision as of 20:28, 15 August 2008
Line 1:		Line 1:
		+	Hammerhead is the GPS receiver chip used in the Neo 1973. The only way currently to use it is via a closed-source binary program. This page describes efforts to write an open source driver. (Mostly abandoned since the release of the Neo Freerunner which uses a different chipsset)
		+
		+	== Repository ==
		+
	We have set up a SCM repository for experimental code and documentation at http://projects.linuxtogo.org/projects/sphyrna.		We have set up a SCM repository for experimental code and documentation at http://projects.linuxtogo.org/projects/sphyrna.

@@ Line 7: / Line 7: @@
 == Background resources ==
-Christian did some stracing on TomTom device, and result is great logs at http://www.maintech.de/download/hammerhead-strace.log . 'pH5' on IRC has put up some traces at http://linuxtogo.org/~ph5/tmp/gllin (a cold start, a hot start and a somewhat longer trace). He even has a software that can init and send command to phase-1 openmoko device in http://linuxtogo.org/~ph5/tmp/hhtest.c . (Please use strace -s9999 -x to produce traces).
+Christian did some stracing on TomTom device, and result is great logs at http://www.maintech.de/download/hammerhead-strace.log . 'pH5' on IRC has put up some traces at http://linuxtogo.org/~ph5/tmp/gllin (a cold start, a hot start and a somewhat longer trace). He even has a software that can init and send command to phase-1 openmoko device in http://linuxtogo.org/~ph5/tmp/hhtest.c . (Please use strace -s9999 -x to produce traces).  http://folks.o-hand.com/andrew/strace-schwartz-oabi is a log of all library calls (i.e. a superset of system calls) made by gllin during a hot start and acquiring the time (but no fix), except acos() because printing all acos() calls would fill gigabytes per second.
 A file giving doppler information on the above longtrace NMEA is on [http://www.mauve.plus.com/gps].

@@ Line 1: / Line 1: @@
 We have set up a SCM repository for experimental code and documentation at http://projects.linuxtogo.org/projects/sphyrna.
-[[User:mmontour]] has created a quick and dirty gtk program called 'satscan' which performs the first steps of a cold-start acquisition. It scans through the satellite numbers 8 at a time in several different frequency bands, and displays a symbol on the screen indicating the strength of each signal. The program (which includes portions of 'hhtest.c') is available here: [http://members.shaw.ca/mmontour/satscan/satscan_1.0-r0_armv4t.ipk]. Description/screenshots are
+[[User:mmontour]] has created a quick and dirty gtk program called 'satscan' which performs the first steps of a cold-start acquisition. It scans through the satellite numbers 8 at a time in several different frequency bands, and displays a symbol on the screen indicating the strength of each signal. The program (which includes portions of 'hhtest.c') is available here: [http://members.shaw.ca/mmontour/satscan/]. Description/screenshots are
 [http://openmoko.togaware.com/survivor/SatScan.html]

@@ Line 11: / Line 11: @@
 http://home.earthlink.net/~cwkelley/ has sources for open-source GPS receiver, and
 http://home.earthlink.net/~cwkelley/documentation.htm is its documentation.
 GP2021 is "dumb" GPS receiver, similar to hammerhead. (But I think it communicates over ISA bus, not over serial). However, its data sheets are freely available. Well, hammerhead marketing tells us that their GPS chip is something special, http://www.gpsworld.com/gpsworld/article/articleDetail.jsp?id=3053 . It seems to differ from "dumb" receivers by doing code phase search in hardware, directly.

← Older revision		Revision as of 01:57, 31 August 2007
Line 4:		Line 4:

	A file giving doppler information on the above longtrace NMEA is on [http://www.mauve.plus.com/gps].		A file giving doppler information on the above longtrace NMEA is on [http://www.mauve.plus.com/gps].
		+
		+	[[User:mmontour]] has created a quick and dirty gtk program called 'satscan' which performs the first steps of a cold-start acquisition. It scans through the satellite numbers 8 at a time in several different frequency bands, and displays a symbol on the screen indicating the strength of each signal. The program (which includes portions of 'hhtest.c') is available here: [http://members.shaw.ca/mmontour/satscan/satscan_1.0-r0_armv4t.ipk].

	[http://en.wikipedia.org/wiki/GPS_signals GPS signals at wikipedia] seems to be required reading for very basics, along with [http://www.colorado.edu/geography/gcraft/notes/gps/gps.html this page from University of Colorado] for more in depth stuff.		[http://en.wikipedia.org/wiki/GPS_signals GPS signals at wikipedia] seems to be required reading for very basics, along with [http://www.colorado.edu/geography/gcraft/notes/gps/gps.html this page from University of Colorado] for more in depth stuff.