26. BlueTooth

BlueTooth on the nuvi 680 functions similar to other BlueTooth enabled Garmin GPS units. Once paired with a BlueTooth enabled cell phone, you can use the nuvi 680 as a hands-free speakerphone to place/receive phone calls, dial a number from your phone's address book, or dial a POI's phone number. The nuvi 680 has a Bluetooth range of approximately 33 feet (10 meters), and a built-in microphone on the front of the unit.

You can also connect an external microphone (not included) if you want, although in my testing there was no noticeable difference between using an external microphone mounted on the visor and the nuvi's internal microphone. In fact, some people told me the nuvi's internal microphone actually sounded better.

Figure 101: Configuring the Bluetooth Settings

Unlike other GPS units, however, the nuvi 680 allows you to use the integrated FM transmitter with your BlueTooth connected cell phone -- making it possible to use your car's stereo speakers as a speakerphone. I absolutely LOVED this feature. Where I live it is illegal to use a cell phone while driving except via speakerphone or earpiece. I've noticed that on most GPS units, the speaker is sufficiently loud when parked, but when driving at highway speeds it becomes difficult to hear the other party on the phone call. Using the FM transmitter to broadcast the call via your car's stereo eliminates this problem.

Figure 102: Adding a Bluetooth Phone

I found the microphone built in to the front of the nuvi worked well. Callers said it didn't sound like I was on speakerphone, and the quality was "good enough". I did notice that when there was a lull in the conversation, the nuvi would mute all sound, prompting me to say "are you still there?". I assume this is part of the background noise canceling the nuvi performs to reduce road background noise, but it's somewhat unnerving to hear complete silence at the other end.

In my review of the TomTom GO 910, I complained that the BlueTooth cell phone integration didn't allow you to view the signal strength or battery life. Garmin has addressed this nicely, and cell phone information can be viewed by tapping the phone icon from the menu page, and then tapping on Status.

The nuvi documentation states that you can pair multiple cell phones to the 680 via Bluetooth, although it doesn't specify how many phones you can pair. I was able to pair 2 phones without issue.

27. Text-to-Speech Voice Quality

Text-to-speech voice quality is good on the 680, although not quite as good as the TomTom GO 910. Speech quality on the nuvi 680 is identical to that of the nuvi 660 or Garmin StreetPilot c550. In my testing, the nuvi did a decent job pronouncing street names and I didn't find the voice abrasive or irritating. The nuvi will also perform text-to-speech on saved addresses in your address book. So if you save an address as "Work", when arriving at the saved location, the nuvi will announce "arriving at work".

28. Using the FM Transmitter

The integrated FM transmitter is one of the best things about the nuvi 680. I was really surprised at how much it added to the user experience. It does add a (small) layer of complexity, but it's hard to deny the benefit of having the navigation system, hands-free speakerphone, and music playback all integrated into your car's stereo system.

Figure 103: Audio Output Selection

Switching from the internal speaker to the FM transmitter is accessed by touching the speaker icon on the Main Menu page, then tapping Audio Output.

Note: A quicker shortcut for switching between the internal nuvi speaker and the FM transmitter is quickly pressing the power button twice.

Figure 104: Setting the FM Frequency for the Transmitter

The nuvi 660 had an "Auto-Tune" feature where the nuvi would step through each frequency on the dial until it found a suitable unused channel. It sounded like a great idea, but was time consuming and poorly implemented. Instead of automatically searching for the best frequency (as the name "Auto-Tune" would suggest), the nuvi would merely prompt you at each frequency and ask if the nuvi was clear and static free. Instead of fixing the Auto-Tune feature, Garmin has just done away with it altogether, which I suppose is better than nothing. Perhaps an improved version of Auto-Tune will re-appear in a future firmware update. While I agree the Auto-Tune needed improvement, I do think it was a useful feature and should be added back.

My only real complaint about the FM transmitter was the weakness of the signal. In my car the antenna is located at the rear of the car, so it's a good 5 feet or so from the windshield, and I noticed some crackling and interference. Garmin's documentation says the unit is designed to be placed near the FM radio, and that vehicles that have the antenna far away from the radio may experience less than optimal quality. That was definitely the case for me, but it was not so poor that it was unusable; music still sounded good and the static was only barely noticeable at high volume.

29. Using the Garmin Lock Feature

Figure 105: Garmin Lock

The nuvi 680 includes a feature called Garmin Lock. Using Garmin Lock, you can set a PIN code and designate a "secure location". A secure location is a saved location on the map where you can unlock the GPS even if you've forgotten the PIN code. Personally this sounds like more of a liability than a help, but if you're into the idea of a password for your GPS, then GPS Lock might be just the ticket. To configure GPS Lock:

• Flip open the antenna
• Tap Settings -> System -> Garmin Lock -> OK
• Enter a four-digit PIN. Tap Yes -> OK

Figure 106: Setting a PIN Code for Garmin Lock

Once a Garmin Lock code has been entered, you must enter the PIN every time the nuvi is powered on. Be forewarned though: if you forget your PIN code AND the saved "Secure Location", you must send the unit back to Garmin to be reset.