Today, my Holux M-241 GPS Logger was giving me a hard time. I wanted to connect it to my Macintosh over Bluetooth and the BT747 Java application for the first time. There’s some fragmented information on the Internet about how it can be done but I was unable to find a useful guide.

So, here’s a complete tutorial on how to set up the Holux M-241 GPS Logger on a Leopard Mac (English OS) using Bluetooth and the latest BT747 Java application. You don’t need to install any drivers for this!

Added 2008-7-12: There’s a new how-to for the latest BT747 version here! The information below is outdated!

1. Download BT747 (I was using BT747_1.46_en_full.zip but the version number may change over time).
2. It will be automatically extracted to a folder named BT747_1 or something similar. Drop the BT747_1 folder to your Applications folder. Rename the BT747_1 folder to GPS instead of BT747_1. The full path now is /Applications/GPS.
3. Turn the M-241 on and use the Bluetooth wizard on the Mac to set the device up. Use the specific passkey 0000 (four zeroes) under passkey options. Once the wizard finishes, the M-241 will show up as paired but not connected. There will be no Bluetooth icon in the M-241 as for now because the serial port hasn’t been opened yet. If it’s set up correctly there’s an entry called tty.HOLUX_M-241-SPPSlave-1 in the /dev directory of your Mac. Open a shell (Terminal) an try to run the command
   cat /dev/tty.HOLUX_M-241-SPPSlave-1
   and the Bluetooth icon on the the M-241 should appear almost immediately. Wait another 30 seconds and the last position information should be dumped in the shell. Press CTRL-C to abort. If it says “No such file or directory” the device may have not been set up correctly on your Mac.
4. Open the GPS folder and edit the bt747_macosX.command script with TextEdit. Not needed if you download the modified script (see below). In this case, replace the script in the /Applications/GPS folder with the downloaded version!
   1. Uncomment (=remove the #) the line that starts with cd /App.. so it looks like this:
      cd /Applications/GPS
   2. Go to the line that starts with CLASSPATH and insert dist/ in front of /BT747_rxtx.jar so the line looks like this:

       CLASSPATH=${ROOT_DIR}/rxtx/RXTXcomm.jar:${ROOT_DIR}/webstart/Waba_only.jar:${ROOT_DIR}/dist/BT747_rxtx.jar:.:$CLASSPATH

   3. Go to the last line and change it so it looks like this:

      java -Djava.library.path=${ROOT_DIR}/rxtx/Mac_OS_X -Dbt747_port="/dev/tty.HOLUX_M-241-SPPSlave-1" waba.applet.Applet /w 400 /h 400 /scale 1 /bpp 8 BT747

5. In the GPS folder, rename the directory starting with rxtx-… to rxtx. In my case the directory was called rxtx-2.1-7-bins-r2. Simply rename it to rxtx
6. Go back to the shell you opened in step 3. Enter the command
   sudo mkdir /var/lock && sudo chmod 777 /var/lock
   You will be asked for your root password. If you forget this step you will get PortInUse exceptions because the program is unable to create a semaphore file to lock your serial Bluetooth port.
7. Run-click the bt747_macosX.command in your GPS folder.
8. Press the button named BLUETOOTH in the BT747 application and after a few seconds there should be some information displayed about the connected device in the BT747 connection (”Con”) tab.
9. Click on the file tab and modify the output directory to /Applications/GPS and press “Apply&Set the above values”.
10. Change to the log tab and test if you can download the track log file. Press the “Get Log” button to do this. The track log will be downloaded to your GPS folder.
11. That’s it!

If you don’t like script editing, download the bt747_macosX.command script in the download section of this website. You can omit step 4 in this case. The script was tested with BT747 1.46.

• How-To: Holux M-241 with BT747 v1.52 GPS logger software over Bluetooth
  Here’s a new HOW-TO
• BT747 GPS logger application with new user interface
  My favorite GPS datalogge
• Nikon D80 RAW .NEF GPS geotagging workflow on the Mac
  I already wrote a few art