moving things around and adding examples for mic hat code

mic_hat_examples/online_service_demos/alexa.py

@@ -0,0 +1,53 @@
+"""
+Hands-free Voice Assistant with Snowboy and Alexa Voice Service. The wake-up keyword is "alexa"
+
+Requirement:
+    pip install avs
+    pip install voice-engine
+"""
+
+
+import time
+import logging
+from voice_engine.source import Source
+from voice_engine.kws import KWS
+from avs.alexa import Alexa
+from pixels import pixels
+
+
+def main():
+    logging.basicConfig(level=logging.DEBUG)
+
+    src = Source(rate=16000, frames_size=320)
+    kws = KWS(model='alexa', sensitivity=0.8)
+    alexa = Alexa()
+
+
+    alexa.state_listener.on_listening = pixels.listen
+    alexa.state_listener.on_thinking = pixels.think
+    alexa.state_listener.on_speaking = pixels.speak
+    alexa.state_listener.on_finished = pixels.off
+
+
+    src.link(kws)
+    kws.link(alexa)
+
+    def on_detected(keyword):
+        logging.info('detected {}'.format(keyword))
+        alexa.listen()
+
+    kws.set_callback(on_detected)
+
+    src.recursive_start()
+
+    while True:
+        try:
+            time.sleep(1)
+        except KeyboardInterrupt:
+            break
+
+    src.recursive_stop()
+
+
+if __name__ == '__main__':
+    main()