We've been working with the Quad for a while and audio input/output is simple via the connectors on the board (and direct Android support through the api, no need to go through Arduino). We're very interested in switching over to the Neo because of its smaller form factor (a big plus for a small enclosure we're working with) but I can't find any information about how to read/write audio streams (or what hardware connectors we'd use). Does anyone have any ideas how to go about this? I2C? S/PDIF? (presumably via arduino?) Two more possibilities would be to use the audio-output part of the hdmi connector (we're using the 7" lvds screen so the hdmi "port" is available, or the audio part of it) but not sure how to "wire" this (including the software stack starting with android's api). Also, that would only solve the ouput part not the input/microphone. We also considered a USB-to-audio type setup. This could work and USB-audio is builtin Android starting with Lollipop. This seems most promising especially since Marshmallow (6.0) is now (or soon to be) on the Neo. A cheap $4 dongle would give us the microphone/speaker ports we'd need. Also the cleanest fastest solution, if that works. We're now leaning in that direction. Does anyone have any experience with this? Both opinions or recommendations welcome. Thanks in advance. Freddy.