Stuttering audio when sending to bluetooth receiver via bluealsa

[rcr]

I'm trying to send a music from my NAS on the base of Cuibetruck (Allwinner Tech SOC A20 ARM Cortex-A7 Dual-Core T) Ubuntu Xenial with Armbian Linux 3.4.113-sun7i with bluealsa to my bluetoothreceiver connected to speakers. My working configs are in my answer to the question: https://askubuntu.com/questions/1197072/sending-audio-to-bluetooth-speaker-with-bluealsa

Anyway when I play mp3 with mpd or wav with aplay the music is extremely stuttering. Question on bluealsa Github (https://github.com/Arkq/bluez-alsa/issues/279) ended with advice to check UART set up (which is already too complicated for me). My question is anybody managed to setup a nice and smooth audio output to bluetooth speakers from Cubietruck? Does it have anything with UART set up to do? Maybe someone have an idea?

[rcr]

As long as I didn't get any suggestion I came to idea to try to update my bluetooth module's firmware which I guess a bit old right now:

 

[ 16.278794] [ap6210] Final fw_path=/lib/firmware/ap6210/fw_bcm40181a2.bin

[ 16.284490] [ap6210] Final nv_path=/lib/firmware/ap6210/nvram_ap6210.txt

[ 16.307198] [ap6210] download firmware /lib/firmware/ap6210/fw_bcm40181a2.bin

[ 16.665709] [ap6210] Firmware up: op_mode=0x0005, Broadcom Dongle Host Driver mac=ac:83:f3:a8:72:fd

[ 16.735412] [ap6210] Firmware version = wl0: Mar 10 2014 14:59:50 version 5.9

 

I found this https://github.com/armbian/firmware/tree/master/ap6210 which I think is what I need. Can anyone tell me how do I perform a firmware update?