because here is so much feedback/and website-views on this ES9028Q2M i thought i write something about it again..
after thinking about programming this STM 8S103F3 MCU on the board (and see some Arduino IDE tuturials to become a LED blinking par example->https://learn.sparkfun.com/tutorials/sik-experiment-guide-for-arduino—v32/experiment-1-blinking-an-led , super nice a MUST to watch !! 😉 ) and examining the layout i see that there are also these „Vol+“,“Vol-„, „Delay“ (means filter-settings (FIRs) i think) and the „DSD“ + „PCM“ holes for Diodes/LEDs..
so i think u need only an LED (i would say Blue for DSD and Red for PCM) and a 220 Ohm-Resistor->
to make this LEDs „shine“ 😉
also with such Buttons (here i had measurements about 1cm*0,7cm (100mm*70mm)) it must be possible to have a HW-Volume and Filter-Control..
but u have to solder it right 😉 ..
another possibility would also be to solder some 4 Male 2.54mm Pin Header on it, and connect it then to a STM32F103C8T6 by example to control it via this (and with a bluetooth-receiver-transmitter and bluetooth-app par example..)
still thinking about; greets for the moment 😉
i normally „hate“ this Volumio->came back to it by chance..
so, very smooth and clean..not so many pops,clicks and noise..relaxed..->try it !! 😉 (i wondered myself->relatively good alternative to the other rpi-audioplayer at present)
I used „Generic I2S DAC“ and then came „Hifiberry-DAC“ automatically..
tried to upsample it to 384khz but was not possible „ALSA-error“->and so we are back to the main problem with 384khz and this ES9028Q2M-Board (tried to recall it here, before i forgot it again):
Over I2S and the RPI3B its normally only up to 192khz->for more (384khz) u need a kernel patch..
In picoreplayer u can use the „es9023“ overlay and the the „384khz“-option then (as said some articles before); but picoreplayer is not so comfortable..
same at present with MoodeV4B9 and „hifiberry-dac“->because it has not now the advanced and realtime-kernel as before also no 384khz: same at present with Dietpi..
DoP seems possible; and so we come to the next article->DSD-LED (+Volume and FIR-Buttons) on these ES9028Q2M->http://essabre-90xx-rpi.sfb2.com/2017/11/dsd-led-volume-and-fir-buttons-on-these-es9028q2m-boards-diy/