Hacking Cell Phones via Bluetooth Tools under Linux

The KMobileTools application is still considered alpha software, but it looks very promising. It's an add-on KDE application that lets you back up, edit and import your cell phone's contact list to your computer using the KAddressbook application. This lets you synchronize your contact list on your cell phone or PDA to your e-mail contact list. You no longer have to maintain separate contact lists for your cell phone and e-mail clients.

Another interesting feature is the ability to control your cell phone remotely from the computer. You can have the cell phone dial a number saved in the contact list or type in another via the dial-out number field. You also can send SMS messages through your cell phone. This is handy if you need to send a long message and don't want to kill your thumbs by typing it with the phone's keypad. KMobileTools also displays the cell phone's battery charge percentage and signal strength status.

Not to be outdone by KDE, the GNOME desktop also provides a useful set of tools for file transfers to your Bluetooth devices. There is a nice GNOME-based front end to hcitool that can be started by typing gnome-bluetooth-admin from a terminal session. Click the Scan button, and you should see a listing of nearby Bluetooth devices. Open the Nautilus file manger, and type bluetooth:/// in the navigation toolbar. An icon representing your phone or PDA should appear. Next, open another Nautilus session, drag the icons of the files you want to transfer and drop them onto the Bluetooth device's icon. You should see a message on your cell phone asking if you want to accept the files from your computer. You also can right-click on the icon for the file you want to send and select Send via Bluetooth to initialize the file transfer. Once the transfer is complete, you should see the new file on your cell phone.

Another great application is Phone Manger, which is GNOME's answer to KMobileTools. Phone Manager lets you monitor your device's status, send and read SMS messages to and from your phone and integrate your contact list with Evolution's address book.

Now that you can push and pull files to and from your cell phone, let's create some ringtones. Why create a custom ringtone? You can be lazy and buy them for $2.50 US each from your service provider, or you can have some fun, learn something new and save yourself some money. Personally, I prefer the latter. Many newer cell phones let you play standard MP3 files without any tweaking whatsoever.

If your phone has limited storage space, it might be prudent to reduce the size of the audio file in Audacity. The first step is to import your song into a new project in Audacity. Trim the song to an approximately 30-second clip of a section of the song that you like. Next, modify the clip so it's in mono. (This shrinks the file size further.) Click the track's filename, and select Split Stereo Track. Delete the right channel of the clip by clicking the X in the upper-left corner of the track. Select the remaining channel, and click on the down arrow next to the track name. You will see a drop-down menu containing entries for Mono, Left Channel and Right Channel. Select Mono.

Next, you need to normalize the clip. First, press Ctrl-A to select the whole track. Then, select the normalize entry in the Effect drop-down menu in Audacity's main toolbar.

Now, you're ready to encode the MP3 file of your ringtone. Click File, and select Export Selection as MP3. Take the new MP3 file and simply move it into the audio folder on your cell phone as described earlier in the article. This is a great method for creating customized ringtones using a FOSS application.

It is possible to use your Bluetooth-enabled cell phone or PDA as a modem if it has GPRS or EDGE network capability. One caveat is that many cell-phone providers lock this functionality out of their phones unless the customer has a data plan with them. Data plan prices vary significantly, depending upon how much throughput you are allowed and which carrier you use. I obtained an introductory plan for $25 US per month. An unlimited data plan probably costs in the range of $60 US a month. This is a good option for road warriors who might be traveling into areas where broadband is not readily available, but cell-phone service is. Nowhere on my cell-phone provider's Web site did it mention that this service is available to Linux users. However, the provider offers a custom application for Windows users. The application provides users with Internet access using their service. Mac OS X users were relegated to a How-To document on the customer support Web site.

It was only when I requested to talk to the technical support that the provider openly acknowledged that connectivity under Linux was possible. I was then provided with a custom script that calls the WvDial PPP dial-up application. The script contained specific initialization parameters to pass to the phone and connect to the dial-up service. The technical support person at first claimed I would be able to use this service only if I connected the cell phone to my laptop via a custom Motorola USB cable. Conveniently, they sell this cable for $30 US and promptly offered to sell it to me. I communicated that I was able to pass data to/from my phone seamlessly using a generic Bluetooth dongle. At this point, the technical support person admitted that the USB cable was not necessary. I then paid for a month's worth of service and was informed that customer support does not offer any assistance to Linux users. Nothing new there. Subsequently, I sent an e-mail to customer support asking that they acknowledge on their support pages that the data service works flawlessly with Linux. I have not heard back from them at the time of this writing.