Putting It All Together

I’ve now blogged about most of the pieces I needed for my morning greeter project. So now it’s time to write about putting it all together into a single, working solution.

Here’s a quick recap of the pieces so far:

1. Raspberry Pi with Bluetooth USB Adapter
2. Alexa Voice Service Client
3. Text-to-Speech
4. Custom Alexa Skills:
   • News
   • Stocks
   • Traffic
5. Bluetooth Proximity Detection

Alexa Agent

To make it easier to send commands to Alexa, I wrote a simple agent class using Python with two main interface methods.

    def say(self, input):
        """Alexa will say the text.
        
        @param: input: Text you want Alexa to say.
        @type: input: str or list of str
        """
        # do some stuff

    def ask(self, input):
        """Ask Alexa to do something(s).
        
        @param: input: Text command you want to send to Alexa.
        @type: input: str or list of str
        """
        # do some stuff

The agent will take care of TTS, sending the request to AVS, and playing back the response. The full code is available in my Github repository: alexa-agent

Alexa API

Next, I needed a way to connect triggers (e.g. bluetooth proximity detection) to Alexa commands. A flexible way for doing this is through a simple web service API that can be invoked via HTTP requests.

This can be done very quickly using Flask:

#!/usr/bin/env python

from flask import Flask, jsonify
from alexa_agent import AlexaAgent


app = Flask(__name__)


@app.route('/morning-report', methods=['GET'])
def morning_report():
    agent = AlexaAgent()
    agent.wakeup()
    agent.ask([
        "What is today's date",
        "What time is it",
        "How's the weather"
    ])
    return jsonify({'code': 200, 'message': 'Morning report delivered!'})


if __name__ == '__main__':
    app.run(port=8888, debug=True)

The above code, along with sample WSGI and Apache configuration files is available in my Github repository: alexa-agent-flask

Note: If you’re using custom Alexa skills, make sure to modify the list of commands with the appropriate intent phrases.

Bluetooth Scanner

The last piece is the bluetooth proximity detection trigger. I recently updated my bluetooth-proximity repository with a simple scanner script that can be modified for this purpose.

Simply replace the dummy_callback() function with a function that will call the Flask API endpoint for the morning report. For example:

import requests

def get_morning_report():
    requests.get('http://127.0.0.1/alexa-api/morning-report')

You can test if the bluetooth scanner is working by running the script manually (i.e. python bluetooth_scanner.py). Once it’s working, you can set it up as a simple systemd service using the steps below.

Systemd Service

1. Write a systemd service file named bluetooth_scanner.service

    [Unit]
    Description=Bluetooth Scanner
   
    [Service]
    Type=simple
    ExecStart=/usr/bin/bluetooth_scanner.py
   
    [Install]
    WantedBy=multi-user.target
   

2. Copy the bluetooth_scanner.py script to /usr/bin/
3. Copy the bluetooth_scanner.service file to /lib/systemd/system/
4. Reload the systemd daemon using the command systemctl daemon-reload
5. Start the bluetooth scanner service using the command: systemctl start bluetooth_scanner.service
6. Enable the service to auto-start with the system using the command: systemctl enable bluetooth_scanner.service

That’s it! You should now have a bluetooth triggered morning report. I hope this series of blog posts has been helpful. Thanks for reading.