Feasycom’s Bluetooth Audio module includes a series of profiles for data and audio transmission functions. When developers are writing and debugging programs, they often need to configure the module firmware’s functionality. Derfor, Feasycom provides a set of AT commands with a specific format to facilitate developers in configuring profiles anytime, hvor som helst. This article will introduce how to use these AT commands to developers using Feasycom Bluetooth -lyd modules.

Først, the format of Feasycom’s AT commands is as follows:

AT+Command{=Param1{,Param2{,Param3…}}}<CR><LF>

Note:

– All commands start with “PÅ” and end with “<CR><LF>”

– “<CR>” represents the carriage return, corresponding to “HEX” som “0x0D”

– “<LF>” represents the line feed, corresponding to “HEX” som “0x0A”

– If the command includes parameters, the parameters should be separated by “=”

– If the command includes multiple parameters, the parameters should be separated by “,”

– If the command has a response, the response starts with “<CR><LF>” and ends with “<CR><LF>”

– The module should always return the result of the command execution, returning “OK” for success and ERR<code> for failure (the figure below lists the meanings of all ERR<code>)

Error Code | Meaning

————|——–

001 | Failed

002 | Invalid parameter

003 | Invalid state

004 | Command mismatch

005 | Busy

006 | Command not supported

007 | Profile not turned on

008 | No memory

Andre | Reserved for future use

The following are two examples of AT command execution results:

  1. Read the Bluetooth name of the module

<< AT+VER

>> +VER=FSC-BT1036-XXXX

>> OK

  1. Answer a call when there is no incoming call

<< AT+HFPANSW

>> ERR003

NESTE, let’s list some commonly used profiles as shown below:

– Spp (Seriell portprofil)

– GATTS (Generic Attribute Profile LE-Peripheral role)

– GATTC (Generic Attribute Profile LE-Central role)

– HFP-HF (Håndfri profil)

– HFP-AG (Hands-Free-AG Profile)

– A2DP-Sink (Avansert lyddistribusjonsprofil)

– A2DP-Source (Avansert lyddistribusjonsprofil)

– AVRCP-Controller (Audio/Video remote controller Profile)

– AVRCP-Target (Audio/Video remote controller Profile)

– HID-DEVICE (Human Interface Profile)

– Pbap (Phonebook Access Profile)

Endelig, we list the corresponding AT commands for the profiles mentioned above in the table below:

Command | AT+PROFILE{=Param}

Param | Expressed as a decimal bit field, each bit represents

BIT[0] | Spp (Seriell portprofil)

BIT[1] | GATT Server (Generic Attribute Profile)

BIT[2] | GATT Client (Generic Attribute Profile)

BIT[3] | HFP-HF (Hands-Free Profile Handsfree)

BIT[4] | HFP-AG (Hands-Free Profile Audio Gateway)

BIT[5] | A2DP Sink (Avansert lyddistribusjonsprofil)

BIT[6] | A2DP Source (Avansert lyddistribusjonsprofil)

BIT[7] | AVRCP Controller (Audio/Video remote controller Profile)

BIT[8] | AVRCP Target (Audio/Video remote controller Profile)

BIT[9] | HID Keyboard (Human Interface Profile)

BIT[10] | PBAP Server (Phonebook Access Profile)

Response | +PROFILE=Param

Note | The following profiles cannot be enabled simultaneously via AT commands:

– GATT Server and GATT Client

– HFP Sink and HFP Source

– A2DP Sink and A2DP Source

– AVRCP Controller and AVRCP Target

Using AT commands to configure the Profile of Feasycom Bluetooth -lydmodul is implemented in binary form in the firmware program. The parameters need to be configured by converting the corresponding BIT positions to decimal numbers. Here are three examples:

1. Read the current profile

<< AT+PROFILE

>> +PROFILE=1195

2. Enable only HFP Source and A2DP Source, disable others (Dvs., both BIT[4] and BIT[6] are 1 in binary, and other BIT positions are 0, the converted decimal sum is 80)

<< AT+PROFILE=80

>> OK

3. Enable only HFP Sink and A2DP Sink, disable others (Dvs., both BIT[3] and BIT[5] are 1 in binary, and other BIT positions are 0, the converted decimal sum is 40)

<< AT+PROFILE=40

>> OK

The complete AT commands can be obtained from the corresponding product’s general programming manual provided by Feasycom. Below are only a few main Bluetooth Audio module general programming manual download links:

– FSC-BT1036C (Master-Slave integrated, can switch between audio master and audio slave functions through commands)

– FSC-BT1026C (Supports audio slave function and TWS function)

– FSC-BT1035 (Supports audio master function)