I’m experiencing some problems with the BT_VOL_CONFIG, more specific with the a2dp volume steps, right now I have it set to 10 (which is the default), but it still changes depending on which device I have connected to the module. For example for an Iphone I have 17 steps, and for a Samsung I have 16.
Am I missing something on the configuration, or this configuration is not actually to set a rigid number of steps for the A2DP?
This is my configuration at the moment:
AUDIO_ANALOG=0 0 0 OFF
AUDIO_DIGITAL=0 48000 64 100200 OFF
BATT_CONFIG=ON 145 3700 1500 150
BC_SMART_CONFIG=68E3 28F0 89F7 D93C
BEACON_DATA=0 00 11 22 33 44 55 66 77 88 99 AA BB CC DD EE FF 04 D2 16 2E EE
BLE_CONFIG=0 OFF 80 OFF
BLE_CONN_PARAMS=128 12 24 40 0 400 100 400 400 64 400 400
BT_VOL_CONFIG=9 50 10 1
DEVICE_ID=0001 0002 0003 0004 0005 0006 0007 0008
ENABLE_SPP_SNIFF=OFF 0 0 0 0 0
HFP_CONFIG=OFF ON OFF OFF OFF OFF
MM=OFF OFF 0 OFF OFF OFF OFF OFF
PROFILES=3 0 3 0 3 3 0 0 0 0 2 0
SPP_UUID=00 00 11 01 00 00 10 00 80 00 00 80 5F 9B 34 FB
TWS_CONFIG=OFF 1 2
UART_CONFIG=9600 OFF 0
Is there any problem with your device or phone when the A2DP volume steps change to 17 on iPhone or 16 on Samsung? Or simply you just see that number change in each type of phone.
I have connected BC127 to my iPhone and BT_VOL_CONFIG=A 60 10 1 is the default, they work properly.
Moreover, I also changed that A2DP volume step to 17 or 16, and the device still works fine.
I simply just see the number of steps change with different devices, for example for a computer is double the number of steps from a phone.
I just wanted to know if that volume step is not strict when you are changing the volume through the phone or if it only apply when changing the volume through the BC from the GPIO’s.
As far as I read in the documentation, AVRCP Absolute Volume is in the range 0-127, A2DP volume steps are used to divide the range from 0-127.
For example, for the Iphone the number of steps between 0 and 127 is 17, so you go from 0 to 7 and then to 15 and so on until you reach 127.
But for the Android you have 16 steps, so you go from 0 to 9 and then to 17 and then 26 and so on.
Hey @jerdung !
Yes I understood that the A2DP is just diving the steps from AVRCP into groups, my question was, I thought that when you set up a max value for the steps on the BC, no matter what device you are connected and its number of steps for A2DP, the BC would force the number of steps to be the ones that I put on the configuration, but that’s not what’s happening.