Hi Folks ! I'm starting this new thread about BT hands free phone with this new project: Ultimate CarPhone :-)
Forget about all the Bluesoleil hassle and follow me on this one. I got the Bluetooth dev board yesterday and it is very promising... I tested it and at last I can make decent phone calls and people say they hear me. well I'm using the Andrea killer microphone DA-350 but I will test the board with a simple microphone. the board does Noice and echo cancel out of the box !!!
here is a link to the dev board (I paid 162€ shipping included to france):
1. Make a small phone app to control the board.
2. try to figure out how to integrate the board in the sound setup. I had to diconnect my sound card yeserday to test. The board has a lin-in jack. I'll talk to the Laird guys about this. The idea is to use the board as a passthough for carpc sound and to mute this sound when a call comes in. if that's not possible i'll have to figure out a soultion. your suggestions are welcome :-) Simple and easy way is to add small dedicated speaker under the seat and connect the speaker ou line of the board to it and mute sound (throught the phone app) when a call comes.
By the way this is the first post about this project on the internet as a thank you to Clockwork for his DriveLine
The project can be used with any frontend of course. a plugin should be easy to make for any carpc frontend.
To be contined
Last edited by hadaak; 10-17-2013 at 06:05 AM.
Looks very interesting. Can't wait to see this come together.
Simultaneous A2DP and HFP 188.8.131.52
One scenario of particular interest is a headset scenario with A2DP (sink) enabled for receiving stereo audio and HF-unit enabled for receiving/making calls. The A2DP source and the HFP gateway can be combined in one device (e.g. a mobile phone), but they could also be different devices (e.g. an MP3 player as A2DP source and a mobile phone as HFP gateway). For the first case, we assume that a mobile phone will suspend the A2DP stream before enabling the SCO connection for speech. Once the call is finished, the mobile phone is expected to initiate resumption of A2DP streaming. The only user action required is to answer the call at the BTM5xx module by AT+HFCA (or an appropriate GPIO button assigned to “HF green button”). Asynchronous messages related to suspend/resume actions are listed below (HF messages are not shown here):
APSUS,< (A2DP stream suspended, initiated remotely)
FS8000,INT (8kHz sampling rate on internal codec)
HF”AU1” (SCO connection)
… (ongoing call)
HF"AU0" (SCO disconnected)
FS44100,INT (44.1 kHz sampling rate on internal codec)
APSTR,< (resuming A2DP stream, initiated remotely)
In the second scenario, where the audio source and the HF gateway are different devices, you must take more precautions. Neither device knows if the audio resource of the A2DP sink / HF unit is in use when one requests an audio link. For example, if the mobile phone signals an incoming call and requests a SCO link while A2DP is being streamed from another device, the mobile phone is unaware of A2DP stream and so cannot request its suspension. In this case, the audio stream must be suspended manually by a host microcontroller (AT+APU) before accepting the call. Once the call finishes, the audio stream should be resumed manually by a host microcontroller (AT+APR).
S-register 355 (“audio resource override”) helps to address and automate this scenario. It controls whether incoming/outgoing requests for A2DP or SCO connections are accepted by requiring that a link of another type be suspended (A2DP) or closed (SCO) before accepting/initiating the new link. See Table 4-1 for details of S355.
In an A2DP / HFP simultaneous scenario, it is likely that the user wants different gain settings for SCO and A2DP links. ATI22 (for output) and ATI23 (for input) query the last gain settings used for a SCO connection of the internal codec. ATI24 (for output) and ATI25 (for input) query the last gain settings used for an A2DP connection. S register 356 restores of last SCO gain settings when entering a SCO connection. S-register 357 restores the last A2DP gain settings when entering an A2DP connection. Refer to Table 4-1 for details.
184.108.40.206.1 Issue / workaround with Apple devices
When initiating A2DP from BTM51x with AAC enabled to an iPhone, we have observed regular short drops that can be resolved by changing the HCI role so that the iPhone becomes master of the link. The setting to request slave role for BTM51x on each A2DP and AVRCP connection is:
Where do I get a list of supported AT commands?
I got a device similar to that. It does HFP, BT Audio, AM,FM,HD, CD, USB and it's called a Kenwood head unit....for about $20 less than that board. I'm not knocking the idea of the board, I'm just pointing out how ridiculously expensive it is. Also, be sure to check the licensing for the hardware with regards to retail sales. A development board is one thing, a retail product is another. Ask Mitch about that.
Went and looked at the product. The price isn't quite as bad as I thought, but still $140 or so, and the license does appear to be good for commercial development. Still, by the time you add in the cost of a quality mic and such, you're talking about a very expensive piece of kit.
Last edited by VegasGuy; 10-17-2013 at 12:28 PM.
I get it :-) but I already spent more than three times the price of this board on other CARPC Bleutooth solutions and nothing worked. So here I have something which works :-) And I'm not planning on selling it. I'm just testing it for the carpc community so they know there is HOPE :-)
My intial thinking was if the board works as is carpc guys can buy it as is and use my app or their own with it. I found out it does echo cancel without a CVC licence so it's good. no need to buy anything else in terms of licensing to use it. I even think that CSR offer a free CVC license for a dev board !!!
Will test it with a standard mic tomorrow and see how it behaves.