Build your own Amazon Echo - Turn a PI into a voice controlled gadget [Resources_Hands on]

As a young man, I yearned for a machine like the ship's computer on Star Trek: a gadget that can listen and obey a human voice, and answer in kind. Fifteen years ago, after reading about university researchers who had gotten voice-controlled artificial intelligence systems working, I taught myself Linux and set up a server in my attic in the hope that the technology had arrived to let me build such a thing myself. It had not. But now voice control has come to the masses. Amazon's Echo smart speaker was the hot holiday gift of 2016, and last year the company released the smaller Dot and Tap gadgets. Like the Echo, these tie into Amazon's intelligent personal assistant, Alexa. It is Alexa, running in the cloud, that converts your speech into text, interprets the text, and responds verbally, musically, or by passing commands to some other smart gadget such as a Wi-Fi-enabled lightbulb.