Bluetooth Doesn't Work Except on Music Channel — TomTom Community

Bluetooth Doesn't Work Except on Music Channel

I've actually known about this for a long time and figured it had something to do with my car, but apparently it's a problem with the Go Mobile app. Here's the situation.

The car in question is a 2016 Kia Soul. The phone I'm using is an LG V20 running Android 8 (but this problem has been going on since it was running Android 6). The TomTom app will only work with the car's Bluetooth on the music channel, not the voice call, system, notification, alarm, or ring channels.

The problem with that, of course, is that any device connecting to the music channel is considered a media device and must be used instead of the car's radio, whereas the call channel can interrupt whatever is playing on the radio when there's a navigation instruction coming through. But the TomTom app doesn't work with the call channel.

At first and for several years, I figured it must be a shortcoming of the car radio and bought a separate Bluetooth speaker that clips to the visor so I could still listen to the radio. But due to the current problem with renewing the TomTom subscription, I'm taking the opportunity to test some other navigation apps, and they all work just fine using the car's call channel. So does the phone itself. It duly interrupts whatever is playing on the radio whenever a call comes through.

In other words, what I thought was a problem with the car is actually a problem with the app. It's not a deal-killing thing because I do have the external speaker, but I thought I'd let you know.
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Comments

  • [Deleted User][Deleted User] Posts: 0 [Legendary Explorer]
    This seems so ridiculous to me that I kind of doubt it's the reason for this problem, but it appears from analyzing the signal that TT uses A2DP regardless of the Bluetooth channel selected.

    I really can't imagine why anyone would code an app that way, so I have my doubts. To interrupt the sound on the car radio, the app has to use HFP (Hands-Free Protocol), which generates a "prompt" to tell the connected radio that a phone call is coming through. Without the HFP prompt, using the Call channel would be pointless. It simply wouldn't work. The signal would be ignored by the car radio.

    Or to put it in more simple language, using the Call channel isn't enough. The signal has to identify itself as a phone call for the car radio to give it priority over whatever the radio is playing. It doesn't seem to me that the output to BT is identifying itself as a phone call.

    But I could be wrong. In fact, it seems bizarre enough that I suspect that I am. I'll do some more looking later on.

    There may be an option in Android to route all media over HFP. I don't know because I've never come across anything like this before. HFP has been around for... hell, at least 10 years. I can't imagine that it's not coded into the app.

    I'll look for a way to do it at OS level as a diagnostic and possible workaround.
  • [Deleted User][Deleted User] Posts: 0 [Legendary Explorer]
    Well, it doesn't look like there's any native-support for audio re-routing from a specific app to HFP on Android 8; and I don't feel like rooting a phone that otherwise works fine just to hack that functionality into it.

    There are a few apps that claim to be able to do it, but I'm not going to bother. Android does support multiple Bluetooth connections and does allow them to be selectively assigned; so the workaround I'll use will be to route phone calls to the car audio system and media to the aftermarket Bluetooth speaker. The radio volume won't be turned down during spoken navigation instructions that way; but it never has worked properly, so I'm used to that.

    I'll also check the Bluetooth settings in the car radio. As I recall, they were pretty basic. But I do know I can disable A2DP streaming in the radio. Maybe disabling A2DP will force the radio to handle TomTom's connections as HFP calls. I seriously doubt it, however. More likely it will just ignore them altogether. If it does work, it will be because of a quirk in the radio.

    I must say, it's pretty disappointing that TT Go doesn't use HFP to connect to the voice channel. Even free nav apps I've tried have that much figured out. It's not a deal-killer for me because I already have the freestanding BT speaker. But I wouldn't be surprised if many potential customers have walked away from this app because of it. It's a pretty glaring flaw, and the fact that it apparently has existed for as long as I've been using the app is very disappointing.
  • [Deleted User][Deleted User] Posts: 0 [Legendary Explorer]
    Nilsiboy wrote: »

    Okay, thanks.

    That's kind of disappointing, too, knowing that other customers brought this to their attention and it still hasn't been done, especially since as I recall, it's not difficult to do. It's been a while since I coded for Android (I'm semi-retired), but I'm almost certain it's the default behavior for the Headset Client service. I could be wrong, though. It's been a while.

    It makes me wonder whether more important fixes like potential security holes are being addressed promptly. If I recall correctly, BT connections also activate the PDAP service, which provides access to the address book. Because of the short range and the pairing protocol, exploits are rare; but they're not impossible if the app that established the connection has a hole in it.

    I like TomTom. Always have. In terms of maps, traffic, and basic functionality, I don't think they can be beat. But this sort of thing bothers me. :/
  • SinglePointSafetySinglePointSafety Posts: 11 [Master Explorer]
    It bothers me too.... and it makes life very inconvenient because the default on my phone is 'Bluetooth on' (to link with my smart watch). And even more of a problem, when the TT navigation instructions come through the media/BT channel, most times the first few seconds are missing (and my phone is a vanilla Google Pixel 3 running the latest OS)
    GeekOnTheHill: thanks for an eloquent and enlightening summary/explanation of the problem, probably the best I've seen.
  • [Deleted User][Deleted User] Posts: 0 [Legendary Explorer]
    It bothers me too.... and it makes life very inconvenient because the default on my phone is 'Bluetooth on' (to link with my smart watch). And even more of a problem, when the TT navigation instructions come through the media/BT channel, most times the first few seconds are missing (and my phone is a vanilla Google Pixel 3 running the latest OS)
    GeekOnTheHill: thanks for an eloquent and enlightening summary/explanation of the problem, probably the best I've seen.

    Thank you.

    My nagging concerns regarding TT's code stewardship in general have prevented me from renewing this service so far.

    As mentioned (and misspelled) earlier, connecting an Android phone to a vehicle radio activates PBAP (Phone Book Access Protocol) by default so the radio can download the user's contacts. This allows it to identify incoming callers and make outgoing calls by spoken command. It also allows onboard nav apps to use the contacts' location information, if it exists, to route to the contact's location.

    Those are useful features. The problem is that when there's such a glaring error in the BT implementation as omitting the HFP prompt, and when I find that it's been that way for years, it really makes me wonder how well the code is being maintained.

    I haven't uninstalled the app, but I also haven't used it in a while. At the moment, I'm inclined to wait for the next update and see whether it addresses the BT problem. That's the one that really bothers me security-wise because it's a network issue on an app with permission to access sensitive information.
  • Per5678Per5678 Posts: 4 [Apprentice Traveler]
    I've been posting on this issue as well, but didn't have the insight wrt HPF. Really disappointed with TomTom if it is indeed this simple to fix. I experence exactly the same. Audio messages from other apps are able to interrupt the in-car-radio, but not Go.
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