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[Q] Developing a NFC, Wireless charging dock

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Default [Q] Developing a NFC, Wireless charging dock

Hi to the fantastic team of minds on XDA! I'm currently working through building a wireless charging/streaming dock with NFC for my Nexus 5, although the plan is to extend support to any device that supports Wireless Charging & NFC.

Basic concept is for use in a car, but could also be adapted for other situations easily. Basic operation is drop phone in charging area/cradle, NFC tag is read by phone and either launches the music player OR for me in my case, runs tasker to set volume max, play library on shuffle, launch GPS tracking for work/private mileage etc and the phone would stream audio to a receiver wired into the cars headunit.

NFC/Wireless charging.. piece of cake. Audio streaming... not so fun.

I would really like decent audio quality, not quite audiophile level but certainly at least as good as the 3.5mm line out from the headphone jack. Initially I disliked the idea of bluetooth due to quality however looking around I found some Bluetooth 4 APT-X enabled boards that seemed to fit the bill fairly well as apparently APT-X sounds much better in comparison to A2DP (haven't tried out for myself though). Only problem is the Nexus as well as a lot of other devices don't support APT-X. Other than bluetooth I'm really struggling to find a good quality wireless streaming standard that is fairly plug and play. I found a WiFi option via DTS using DLNA but the details on the receiving hardware are sketchy, it also doesn't seem very transparent (requires input from 3rd party apps etc).

I also found a few posts relating to Chromecast enabled media servers that will allow Play music to cast music to them, but again, can't really find any pre made WiFi enabled DLNA "dumb" servers designed to simply capture an audio stream. Again, not very transparent. Ideally it would work natively and without much 3rd party input.. although this may not be entirely possible so I'm open to all options.

So, what are my options? Also, why with Bluetooth 4 with the max bitrate of 20+mbps do we not have a high bit rate audio streaming profile/protocol?

I did consider the idea of a wired DAC, but the major plus on the cable free design is being able to just drop the phone in and grab it out without fiddling for cables. Also the Nexus 5 doesn't support USB DAC OOTB. I also had difficulty sourcing a DAC that would output acceptable audio (at least as good as the headphone jack) for a good price. Everything I found was either expensively high end or nasty & cheap. All I need is a bare board that gets stuffed into a cable box and works! I bought a cheap $5 DAC off ebay ages ago for testing. Worst mistake ever!!! Horrible sound, but hey it was $5

Thanks for any input!

- Auzeras
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If bluetooth sound qualitiy is too bad for you (for me its ok with my JVC radio) i think the aux cable is the only option. But if you have to plug in the cable the "just drop your phone"-concept is gone. I suggest trying to use the USB port for audio out (because aux input isnt a big deal for most of the cars) und charging at the same time. For the dock i think using the brodit docks is ok although these docks are expensive. Alternativly you could try to use a cheaper dock.

For USB audio out i think a cheap DAC like this should be fine, but you need the usb audio recorder pro app (see this thread). Next thing is charging at the same time. Maybe its possible to do it like this with an powered usb hub but you'll have to try that. Overall its more the developing of an USB aux output with the ability of charging but i think its the only option to get the audio qualitiy you want.
audio, charging, dock, streaming, wireless
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