New project

I want to make a datalogger but i am trying to find out what could be the best way to do it. I want to log GPS-data (prefered without a GPS shield because i want to do it myself) and i was thinking about a serial GPS mouse.

The logging must be done on: SD, USB or with XBEE

Dataspeed must be: 5 samples/sec prefered 20x per sec Max Speed robot: 25 m/sec Recording time: minimal 1 hour GPS receiver: 5Hz minimal (prefered 10Hz)

[u]The questions which i have now are:[/u] - is it possible to get serial data from a GPS serial mouse. (I think it can be done. I have seen some articles on Google). But is it fast enough? - if i will be using the GPS datashield, will this be fast enough?

[u]Recording:[/u] - is XBEE fast enough? - is USB transfer fast enough?

Whether you can get GPS data from a GPS mouse depends on the particular device you select. The frequency that it generates data will also depend on the particular device.

The one device I looked at had a much higher price, and much larger size, than a GPS on a shield. If it were me doing this, I'd get a shield with GPS, and know that I would be able to communicate with it.

The accuracy of a GPS is typically +/- 3 meters. 20 unique samples per second would have the robot moving 60 meters per second.

A xbee could transmit the GPS data at that speed, if the GPS can. But, transmit it where?

One hour of data at 20 samples per second is going to be about 6 Meg of data. Even a small SD card will hold that much.

I was thinking about an Holux GR 213

That GPS does not meet some of your criteria. It is a 1 Hz device.

There are, apparently, a number of connectors that can be obtained for the device. None of them will directly connect to the Arduino.

The User’s manual talks about both RS232 and TTL interfaces. RS232 requires hardware between the Arduino and GPS to convert voltages from +12V and -12V to the 0V and 5V that the Arduino uses.

The device requires 12V to operate. You won’t get that from the Arduino. Does your robot have 12V power?

The device claims an accuracy of 5 to 25 meters. Will that be good enough for your purposes?

Finally, the thing is much bigger than a GPS chip on a shield would be. Is that going to be an issue?

Where does your robot operate? You are aware, I hope, the GPS’s only work outdoors.

What are you going to log? How many bytes of data?

As for the frequency of logging... You should know that you'll most likely find little or no value (maybe even som bugs when) logging at higher rate that the rate of your slowest device in your chain of devices (most likely your GPS). No need logging the same data multiple times, in most cases.

I just bought the Arduino Starterpack (adafruit) with GPS Shield and accelerometer. Lets find out how everything will work. I hope i can log the accelerometer data at the SD-card with the GPC Waypoints (coördinates)