Sim 808 defaultly connected to Bluetooth HFP mode


When I connect SIM808 using smartphone the connection seems to get HFP by default.
what if I want to use SPP can we change it in process?

How to make spp as default profile.

if not how to transfer data from phone to Modem in HFP mode?

I would like to connect modem using smartphone and then transfer data from smartphone.

Please help on this.


Hi Sateesh,
The SPP profile is not exposed in Android by default. So install an APP which exposes the SPP profile of Bluetooth. If you have seen in my video I use an APP for it. It’s available on playstore.
You can’t make SPP by default but using this app you can’t transfer data using SPP.

Hi sir,

      The module connected to mobile with  HFP mode. Whenever the HFP profile connected with out Bluetooth device we can't hear the voice of others .that is the main reason for asked that question.

      In valentron bluetooth app sending the data and receiving the data from module. This app connected in spp profile .

HI Sateesh,
So you mean your questions is,
You are not able to hear audio when connected with HFP profile
You want to transfer serial data in HFP mode ?

Could you please elaborate.

Thank you for your quick replay.
I am not able to hear the audio when connected with HFP profile That is the issue.

Mobile is connected to sim808 module with HFP profile
When i get the call i lifted the call but i did not here the audio when i turn off the Bluetooth i here the audio.

If you know how to transfer serial data in HFP mode,Can you please tell me sir.

I have another question
How to enable GPRS on sim808 using AT commands.

It is because the SIM808 is being detected and connected as a headset/earpiece, means its like connecting a headphone to your handset, All audio will get routed to that and no audio will come on handset.
If you are expecting to hear audio on handset when SIM808 is connected in HFP mode its not possible is what i think.
AFAIK, You cannot transfer data in HFP mode, you can only issue HFP commands to answer etc, disconnect call etc.

Thank you for replay.

I tried like below steps.

  1. Sim 808 is automatically connected with HFP profile.
  2. Open the bluetooth application and send the connection request to sim 808 with SPP profile. Here Bluetooth application is also connected to module with SPP profile.
    3.Now both HFP and SPP profile’s connected to sim808. Next i disconnected the HFP profile using the AT+BTDISCONN=1 command. In command 1 is the device id.
    4.Now only Bluetooth app is connected with SPP profile. Here i am able to data transmitting and receiving.

Data means some string .
5.Now i am able to here the audio when i get a call.

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Hi Sateesh,
Thats great that you got it working :slightly_smiling_face:
Thank you for sharing the solution to the community.

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