NMEA Data Logging for the Palm OS

This software has been successfully tested on a Palm Vx, on a Visor, and on a Sony Clié. The Palm OS Version we worked with is 3.5.2.
The only hardware requirements are:

On the boat: a serial output delivering and NMEA flow
On the Palm: a serial connection (no USB or wacky stuff like that)
An appropriate wire in between

The serial port configuration is hard-coded in the program with the following parameters:

Baud Rate	4800
Data Bits	8
Stop Bit(s)	1
Parity	None

For any modification of this configuration, you need to talk to me...

All components have been written in Java, and ported to the Palm OS using JUMP 2.0 (Java User Module for Palm).

This software can be used as it is for free. Positive feedbacks and comments appreciated, please feel free to use the e-mail address mentionned below.

Related to:

The NMEA Specification

Download the prc archive mentionned on the project home page, unzip its content wherever you want, and use your Windows Explorer to navigate to it, then double-click on it, to install it on the Palm next time you synchronize it.
This double-click operation must be done on the machine the Palm Desktop Utility is installed, as it also implies the association between the Hotsync program Hotsync

and the files having a "prc" extension, like the one you've extracted from the zip-file mentionned above.

Installation

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Once you've completed the step described above, you only have to synchronize your PDA using the hotsync utility Hotsync

, which comes with the desktop utilities of the Palm OS.
Another utility to check out your NMEA serial connection is mentionned on another document.

Requirements and Usage

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Now you've installed the application on the Palm, you can use it on board. It requires some hardware, you have to install a 9-pin socket to plug the palm into the serial port of your electronic station. The usual craddle of your PDA should fit if securely fasten; you can also use the cables coming with the Travel Kit, as shown below.

A good installation

Let's now see how to use the program. It's very easy. We will describe the operations you will have to perform to log the data you're interested in. We will show here which button to tap; most of those operations can also be completed through some menu items. We do not describe those possibilities here, you'll see it for yourself...

To start it, just tap the little paperboat labeled "Logging".	You should then see the Home Page of the application, just like this.	You must go at least once to the configuration form, tap the "Config" button.
You can choose to log everything, or to check one or more check boxes. GLL, HDM, MWV and VHW are the best base for a complete logging. Tap Home to save your preferences and return to the Home page.	We're now ready to begin the logging. Tap the "Logging" button.	This is the Logging Form, tap the button labeled "Start Recording" to begin the logging...
This is what you should see. You have informations about the free memory, the current voltage, NMEA buffer, and current data being stored. To stop the logging, tap the button now labeled "Stop Recording".	Once the logging is stopped, you have a Browse utility to check out what has been recorded. Tap the Browse button in the Home page.	Then Open the database, and you can navigate from record to record. Notice that the date and time have been recorded, in addition to the requested NMEA sentences.
Once the data have been uploaded to your PC (using the Conduit, described in another document), you can erase the data you have recorded by tapping the "Reset DB" button.	Tap Yes if you're confident enough... Another dialog box will then appear if the operation is successfully completed.	As we said, most of the operations we've described can be completed not only through the buttons, but also through some menu items. The result is absolutely identical.

More, and Next

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Let's briefly talk about storage.
After our experience, the average size for one NMEA string we're interested in (GLL, HDM, MWV, VHW) is 62.5 bytes, and the average logging speed is 1.72 record/second. That makes a logging rate of ~107.5 bytes/second, then ~6450 bytes/minute or ~387Kb/hour = 0.387Mb/hour. Without external power supply, the Palm can support more or less 5 hours of logging if its batteries are fully loaded at the beginning.

If we log everything, the logging rate becomes 5.22 records/sec (337.36 bytes/sec), which is 3.13 times bigger than above. It is also important to consider that writing into the Palm database consumes more power than just processing.

Once you've logged the data, the next step is to upload them onto a PC to be able to analyze them. This operation is achieved using what's called a Conduit, and is described in another document.

Send your comments or questions to me.