Hi all!   I have browsing the forum quite while but I did not a solution for my problem. I have bought the OP Zero from DX.com and it came with an expansion board which has two additional USB ports, a 3.5 mm AV socket and a built in microphone. And now I would like to use the audio socket as audio output and I want to use its microphone as well. But I headed some problems and I cannot use its audio features .   I am using this kernel: Armbian_5.24_Orangepizero_Ubuntu_xenial_dev_4.9.4   I t