Turning your Nexus 5 into a Moto X: Always-On Listening
When the Nexus 5 came around, a lot of people asked whether or not it would have a very popular feature of the Moto X: it's famous "Ok Google Now" wake-up hotword. People wondered if the MSM8974 chipset of the Nexus 5 supported Always-On Listening, considering various information from Qualcomm.
Well, here's your answer: Nexus 5 - Always-On Listening Proof of Concept
The hardware is there and the software is capable of handling it. It's far from being stable, and not releaseable in the current state (for various reasons). This is only just a proof-of-concept to show that it's possible.
I hope to be able to bring it to more people in the future, but not in the meantime.EDIT:
To further clarify, this is indeed using the dedicated audio processing chip of the S800 - that's the whole point of this PoC. The CPU is indeed turned off and isn't used at all for the audio processing.