GPS logger?

[Gonzzo]

wow.

quite good info here.

I guess I need to give you some more background info. I am a vivid motorbiker. that is, I do make longer trips with the bike. using a Garmin Quest GPS, I'm only able to track (log) 1-2 days worth of travel. unfortunately, the quest is somewhat weak in connectivity. it only has an USB connector, ulike other Garmin equipment that have serial capabilities as well. so, to download Quest track data, I would need my laptop taken with me, and this is just too bulky.

it happens that I have several old GPS cable mice that deliver serial NMEA data. so I took my PDA (iPAQ) with me on trips and used one of the GPS mice and the PDA as logger (there is free software around for this). however, PDA's need to be on power for long trips and they have problems with the connector (mechanically due to vibrations) and with battery temperature.

so I was looking around what other possibilities might exist. and there are plenty, but.. all the devices I found have limitations: too high price (mostly around 500€ and up), only internal and small memory, no connectivity to PDA's, etc.

so, what I am looking for is a device that
- connects to a GPS mouse or a serial Garmin GPS
- logs all NMEA data that comes along (basically no filtering)
- saves the data as plain ASCII files on a SD or MMC
- can be mounted onto my bike (perhaps under the saddle, still providing access to the SD/MMC card)
- does not need any special software to be written on PC or PDA for interfacing and such
- is small and affordable

and what I was imaging to do was:
- let the track logging run as long my bike ignition is on
- on a trip, replace the SD/MMC every now and then (probably every evening) with a new one
- have a PDA with me (which has a SD/MMC slot) and archive/postprocess the NMEA data on it. there are plenty of software available for PDA's for converting data, programming a GPS mouse, showing the track on a map, etc, you name it.

I have asked around with my friends and many of them came over a PDA/mouse combination to a Garmin. thus still have an unneeded mouse at home. on the other hand, cable mice are very cheap in the meantime. other people I have asked have shown interest in a small cheap homebrewed tracking solution for their vehicles that would act as black box and just deliver standard GPS format datafiles on a little SD or MMC. don't ask me for a business case, though. I am far from wanting to make a business out of this. on the other hand, if I find someone here who would be interested to work on this, I would appreciate. frankly, my HW and programming skills were never really good (my quality was debugging).

@ralph, @Art
anyway, I think your points are still valid. it would make sense to think about a version 2 of that device, which would squeeze NMEA data, but still logging it onto the SD/MMC.

taking the 16 bytes proposed by Art, using e.g. a 3 second log interval, assuming a bike/vehicle is in use for 10hours a day, this would end up in 192kB per day and roughly 32MB per full year. you see, I'm not very memory sensitive as long as there are cheap SD's or MMC's around.

now the next phase is more.. let's say.. looking into the future.. therefore
[dream mode ON]
I want to have a little box on the bike that
- logs GPS data on an SD/MMC card (see above)
- shows me the gear I'm in on a display
- logs more data from the bike to the SD/MMC together with the GPS data, for example: gear, outside temperature, oil temperature, drehzahl (RPM), etc.

while browsing the internet, I found this site http://members.aon.at/w.walter/page_4_1.html that describes a datalogger for RC planes. I was intruiged by it, thus all the ideas above came up.
[dream mode OFF]

I hope you now understand why I have those silly ideas above...

dan

[NavMicroSystems]

Dan,

your ideas so far are not that stupid, it is all feasable.

If you like SD that much why don't you just go and get one of the CompSys SDMM3X Kits with 18F252 ($57.00)

With some programming it would do all you need at a reasonable costs.

[Gonzzo]

Dan,

your ideas so far are not that stupid, it is all feasable.

If you like SD that much why don't you just go and get one of the CompSys SDMM3X Kits with 18F252 ($57.00)

With some programming it would do all you need at a reasonable costs.

yeah.. programming..

I'll try. perhaps. (my vacation just ends this weekend)

thanks

dan

[NavMicroSystems]

yeah.. programming..

I'll try. perhaps...

dan

Dan, I'm waiting for your response on my latest PM . . .

[cosmomen]

Hi all,

I'm looking for a solution to capture NMEA data with a PIC micro and retransmit them on another serial interface... a kind of NMEA repeater.
My only problem is that fro example GPGAA sentences are not the same lenght:
$GPGGA,130524,4650.8982,N,01650.2497,E,0,00,,,M,,M ,,*5A
$GPGGA,170834,4124.8963,N,08151.6838,W,1,05,1.5,28 0.2,M,-34.0,M,,,*75

I try to mace something like:
......

dim GPGGA[i don't know the lenght] as byte

SERIN PORTB.0, 16572, [ WAIT( "$GPGGA," ) , STR GPGGA ] 'this would store the string if I would know its lenght
SEROUT PORTB.2, 16572, ["$GPGGA," , str GPGGA, 10, 13]

something like this... :-)
Please help me!!!

[eoasap]

this is what i do for GPS data. (simplified, but this will work). NMEA sentences are ended with a CR, LF, so i loop through the data, checking for a CR, once its received i set a flag and pad with zeros. this gives me a constant length output of the complete NMEA sentence without chopping off any data. There are probably more efficient ways which dont add extra bytes, and the loop takes a bit of time, but at least it works

'record in 70 bytes
SERIN2 GPS_TXA, GBAUD, [wait("$GPGGA"),str GPGGA_IN\80]


'CLEAN UP THE GPGGA Read
CR_BYTE = 0
for i = 0 to 77
if GPGGA_IN[i] = 13 then
CR_BYTE = 1 'set flag that CR has been recorded
GPGGA_IN[i] = 160 'replace CR with a space
endif

if CR_BYTE = 1 then
GPGGA_IN[i] = 160 'pad with zeros
endif
next i
GPGGA_IN[78] = 13
GPGGA_IN[79] = 10

'END CLEAN GPRMC READ