DWR - An Alexa voice enabled maze-solving LEGO robot

#!/usr/bin/env python3

import time
import logging
import json
import random
import threading
import string

from agt import AlexaGadget

from ev3dev2.led import Leds
from ev3dev2.sound import Sound
from ev3dev2.motor import OUTPUT_A, OUTPUT_D, MoveTank 

# Set the logging level to INFO to see messages from AlexaGadget
logging.basicConfig(level=logging.INFO)

lower_case = string.ascii_lowercase[:10] 

class MindstormsGadget(AlexaGadget):

    def __init__(self):

        super().__init__()
        
        self.leds = Leds()
        self.sound = Sound()
        self.tank = MoveTank(OUTPUT_A, OUTPUT_D)

    def on_connected(self, device_addr):
        """
        Gadget connected to the paired Echo device.
        :param device_addr: the address of the device we connected to
        """
        self.leds.set_color("LEFT", "GREEN")
        self.leds.set_color("RIGHT", "GREEN")
        print("{} connected to Echo device".format(self.friendly_name))

    def on_disconnected(self, device_addr):
        """
        Gadget disconnected from the paired Echo device.
        :param device_addr: the address of the device we disconnected from
        """
        self.leds.set_color("LEFT", "BLACK")
        self.leds.set_color("RIGHT", "BLACK")
        print("{} disconnected from Echo device".format(self.friendly_name))

    def _forward(self, dur):
        self.tank.on_for_rotations(50,50,1.3*dur)

    def _backward(self, dur):
        self.tank.on_for_rotations(-50,-50,1.3*dur)

    def _turn_right(self):
        self.tank.on_for_rotations(-50,-50,1.)
        self.tank.on_for_rotations(50,10,1.7)
        self.tank.on_for_rotations(-50,-50,.15)

    def _turn_left(self):
        self.tank.on_for_rotations(-50,-50,1.)
        self.tank.on_for_rotations(10,50,1.8)
        self.tank.on_for_rotations(-50,-50,.15)
        
    def on_custom_mindstorms_gadget_control(self, directive):
        payload = json.loads(directive.payload.decode("utf-8"))
        print("Control payload: {}".format(payload))
        try:
            for i, idx in enumerate(range(1,11)):
                idx_str = str(idx)
                duration = 1
                duration = payload[lower_case[i]]
                if duration == 'to':
                    duration = 2
                duration = int(duration)
                if payload[idx_str] in ['none']:
                    pass
                if payload[idx_str] in ['left','go left','turn left']:
                    self._turn_left()
                if payload[idx_str] in ['right','go right','turn right']:
                    self._turn_right()
                if payload[idx_str] in ['forward', 'go forward']:
                    self._forward(duration)
                if payload[idx_str] in ['backward', 'back', 'go backward']:
                    self._backward(duration)

        except KeyError:
            print("Missing expected parameters: {}".format(directive))


if __name__ == '__main__':
    # Startup sequence
    gadget = MindstormsGadget()
    gadget.sound.play_song((('C4', 'e'), ('D4', 'e'), ('E5', 'q')))
    gadget.leds.set_color("LEFT", "GREEN")
    gadget.leds.set_color("RIGHT", "GREEN")

    # Gadget main entry point
    gadget.main()

    # Shutdown sequence
    gadget.sound.play_song((('E5', 'e'), ('C4', 'e')))
    gadget.leds.set_color("LEFT", "BLACK")
    gadget.leds.set_color("RIGHT", "BLACK")

const Alexa = require('ask-sdk-core');
const Util = require('./util');
const Common = require('./common');

// The namespace of the custom directive to be sent by this skill
const NAMESPACE = 'Custom.Mindstorms.Gadget';

// The name of the custom directive to be sent this skill
const NAME_CONTROL = 'control';

const LaunchRequestHandler = {
    canHandle(handlerInput) {
        return Alexa.getRequestType(handlerInput.requestEnvelope) === 'LaunchRequest';
    },
    handle: async function(handlerInput) {

        let request = handlerInput.requestEnvelope;
        let { apiEndpoint, apiAccessToken } = request.context.System;
        let apiResponse = await Util.getConnectedEndpoints(apiEndpoint, apiAccessToken);
        if ((apiResponse.endpoints || []).length === 0) {
            return handlerInput.responseBuilder
            .speak(`I couldn't find an EV3 Brick connected to this Echo device. Please check to make sure your EV3 Brick is connected, and try again.`)
            .getResponse();
        }

        // Store the gadget endpointId to be used in this skill session
        let endpointId = apiResponse.endpoints[0].endpointId || [];
        Util.putSessionAttribute(handlerInput, 'endpointId', endpointId);

        return handlerInput.responseBuilder
            .speak("Welcome, you can start issuing move commands")
            .reprompt("Awaiting commands")
            .getResponse();
    }
};

// Construct and send a custom directive to the connected gadget with
// data from the MoveIntent request.
const MoveIntentHandler = {
    canHandle(handlerInput) {
        return Alexa.getRequestType(handlerInput.requestEnvelope) === 'IntentRequest'
            && Alexa.getIntentName(handlerInput.requestEnvelope) === 'MoveIntent';
    },
    handle: function (handlerInput) {
        const request = handlerInput.requestEnvelope;
        const one = Alexa.getSlotValue(request, 'One');

        // All others are optional, use default if not available
        const two = Alexa.getSlotValue(request, 'Two') || "none";
        const three = Alexa.getSlotValue(request, 'Three') || "none";
        const four = Alexa.getSlotValue(request, 'Four') || "none";
        const five = Alexa.getSlotValue(request, 'Five') || "none";
        const six = Alexa.getSlotValue(request, 'Six') || "none";
        const seven = Alexa.getSlotValue(request, 'Seven') || "none";
        const eight = Alexa.getSlotValue(request, 'Eight') || "none";
        const nine = Alexa.getSlotValue(request, 'Nine') || "none";
        const ten = Alexa.getSlotValue(request, 'Ten') || "none";
        const a = Alexa.getSlotValue(request, 'A') || "1";
        const b = Alexa.getSlotValue(request, 'B') || "1";
        const c = Alexa.getSlotValue(request, 'C') || "1";
        const d = Alexa.getSlotValue(request, 'D') || "1";
        const e = Alexa.getSlotValue(request, 'E') || "1";
        const f = Alexa.getSlotValue(request, 'F') || "1";
        const g = Alexa.getSlotValue(request, 'G') || "1";
        const h = Alexa.getSlotValue(request, 'H') || "1";
        const i = Alexa.getSlotValue(request, 'I') || "1";
        const j = Alexa.getSlotValue(request, 'J') || "1";

        // Get data from session attribute
        const attributesManager = handlerInput.attributesManager;
        const endpointId = attributesManager.getSessionAttributes().endpointId || [];

        // Construct the directive with the payload containing the move parameters
        const directive = Util.build(endpointId, NAMESPACE, NAME_CONTROL,
            {
                type: 'move',
                1: one,
                2: two,
                3: three,
                4: four,
                5: five,
                6: six,
                7: seven,
                8: eight,
                9: nine,
                10: ten,
                a: a,
                b: b,
                c: c,
                d: d,
                e: e,
                f: f,
                g: g,
                h: h,
                i: i,
                j: j
            });

//        const speechOutput = `ok, doing ${one} then ${two} then ${three} then ${four} then ${five} then ${six} then ${seven} then ${eight} then ${nine} then ${ten}`;
        const speechOutput = `ok, here we go`;

        return handlerInput.responseBuilder
            .speak(speechOutput)
            .reprompt("awaiting command")
            .addDirective(directive)
            .getResponse();
    }
};

// The SkillBuilder acts as the entry point for your skill, routing all request and response
// payloads to the handlers above. Make sure any new handlers or interceptors you've
// defined are included below. The order matters - they're processed top to bottom.
exports.handler = Alexa.SkillBuilders.custom()
    .addRequestHandlers(
        LaunchRequestHandler,
        MoveIntentHandler,
        Common.HelpIntentHandler,
        Common.CancelAndStopIntentHandler,
        Common.SessionEndedRequestHandler,
        Common.IntentReflectorHandler, // make sure IntentReflectorHandler is last so it doesn't override your custom intent handlers
    )
    .addRequestInterceptors(Common.RequestInterceptor)
    .addErrorHandlers(
        Common.ErrorHandler,
    )
    .lambda();

/*
 * Copyright 2019 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
 *
 * You may not use this file except in compliance with the terms and conditions 
 * set forth in the accompanying LICENSE.TXT file.
 *
 * THESE MATERIALS ARE PROVIDED ON AN "AS IS" BASIS. AMAZON SPECIFICALLY DISCLAIMS, WITH 
 * RESPECT TO THESE MATERIALS, ALL WARRANTIES, EXPRESS, IMPLIED, OR STATUTORY, INCLUDING 
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND NON-INFRINGEMENT.
*/

'use strict'

const Alexa = require('ask-sdk-core');

const HelpIntentHandler = {
    canHandle(handlerInput) {
        return Alexa.getRequestType(handlerInput.requestEnvelope) === 'IntentRequest'
            && Alexa.getIntentName(handlerInput.requestEnvelope) === 'AMAZON.HelpIntent';
    },
    handle(handlerInput) {
        const speakOutput = 'You can say hello to me! How can I help?';

        return handlerInput.responseBuilder
            .speak(speakOutput)
            .reprompt(speakOutput)
            .getResponse();
    }
};
const CancelAndStopIntentHandler = {
    canHandle(handlerInput) {
        return Alexa.getRequestType(handlerInput.requestEnvelope) === 'IntentRequest'
            && (Alexa.getIntentName(handlerInput.requestEnvelope) === 'AMAZON.CancelIntent'
                || Alexa.getIntentName(handlerInput.requestEnvelope) === 'AMAZON.StopIntent');
    },
    handle(handlerInput) {
        const speakOutput = 'Goodbye!';
        return handlerInput.responseBuilder
            .speak(speakOutput)
            .getResponse();
    }
};
const SessionEndedRequestHandler = {
    canHandle(handlerInput) {
        return Alexa.getRequestType(handlerInput.requestEnvelope) === 'SessionEndedRequest';
    },
    handle(handlerInput) {
        // Any cleanup logic goes here.
        return handlerInput.responseBuilder.getResponse();
    }
};

// The intent reflector is used for interaction model testing and debugging.
// It will simply repeat the intent the user said. You can create custom handlers
// for your intents by defining them above, then also adding them to the request
// handler chain below.
const IntentReflectorHandler = {
    canHandle(handlerInput) {
        return Alexa.getRequestType(handlerInput.requestEnvelope) === 'IntentRequest';
    },
    handle(handlerInput) {
        const intentName = Alexa.getIntentName(handlerInput.requestEnvelope);
        const speakOutput = `You just triggered ${intentName}`;

        return handlerInput.responseBuilder
            .speak(speakOutput)
            .reprompt("I don't understand this command, try again")
            .getResponse();
    }
};

// Generic error handling to capture any syntax or routing errors. If you receive an error
// stating the request handler chain is not found, you have not implemented a handler for
// the intent being invoked or included it in the skill builder below.
const ErrorHandler = {
    canHandle() {
        return true;
    },
    handle(handlerInput, error) {
        console.log(`~~~~ Error handled: ${error.stack}`);
        const speakOutput = `Sorry, I had trouble doing what you asked. Please try again.`;

        return handlerInput.responseBuilder
            .speak(speakOutput)
            .reprompt(speakOutput)
            .getResponse();
    }
};

// The request interceptor is used for request handling testing and debugging.
// It will simply log the request in raw json format before any processing is performed.
const RequestInterceptor = {
    process(handlerInput) {
        let { attributesManager, requestEnvelope } = handlerInput;
        let sessionAttributes = attributesManager.getSessionAttributes();

        // Log the request for debug purposes.
        console.log(`=====Request==${JSON.stringify(requestEnvelope)}`);
        console.log(`=========SessionAttributes==${JSON.stringify(sessionAttributes, null, 2)}`);
    }
};

module.exports = {
    HelpIntentHandler,
    CancelAndStopIntentHandler,
    SessionEndedRequestHandler,
    IntentReflectorHandler,
    ErrorHandler,
    RequestInterceptor
    };

/*
 * Copyright 2019 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
 *
 * You may not use this file except in compliance with the terms and conditions 
 * set forth in the accompanying LICENSE.TXT file.
 *
 * THESE MATERIALS ARE PROVIDED ON AN "AS IS" BASIS. AMAZON SPECIFICALLY DISCLAIMS, WITH 
 * RESPECT TO THESE MATERIALS, ALL WARRANTIES, EXPRESS, IMPLIED, OR STATUTORY, INCLUDING 
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND NON-INFRINGEMENT.
*/

'use strict';

const Https = require('https');

/**
 * Build a custom directive payload to the gadget with the specified endpointId
 * @param {string} endpointId - the gadget endpoint Id
 * @param {string} namespace - the namespace of the skill
 * @param {string} name - the name of the skill within the scope of this namespace
 * @param {object} payload - the payload data
 * @see {@link https://developer.amazon.com/docs/alexa-gadgets-toolkit/send-gadget-custom-directive-from-skill.html#respond}
 */
exports.build = function (endpointId, namespace, name, payload) {
    // Construct the custom directive that needs to be sent
    // Gadget should declare the capabilities in the discovery response to
    // receive the directives under the following namespace.
    return {
        type: 'CustomInterfaceController.SendDirective',
        header: {
            name: name,
            namespace: namespace
        },
        endpoint: {
            endpointId: endpointId
        },
        payload
    };
};

/**
 * A convenience routine to add the a key-value pair to the session attribute.
 * @param handlerInput - the handlerInput from Alexa Service
 * @param key - the key to be added
 * @param value - the value be added
 */
exports.putSessionAttribute = function(handlerInput, key, value) {
    const attributesManager = handlerInput.attributesManager;
    let sessionAttributes = attributesManager.getSessionAttributes();
    sessionAttributes[key] = value;
    attributesManager.setSessionAttributes(sessionAttributes);
};

/**
 * To get a list of all the gadgets that meet these conditions,
 * Call the Endpoint Enumeration API with the apiEndpoint and apiAccessToken to
 * retrieve the list of all connected gadgets.
 *
 * @param {string} apiEndpoint - the Endpoint API url
 * @param {string} apiAccessToken  - the token from the session object in the Alexa request
 * @see {@link https://developer.amazon.com/docs/alexa-gadgets-toolkit/send-gadget-custom-directive-from-skill.html#call-endpoint-enumeration-api}
 */
exports.getConnectedEndpoints = function(apiEndpoint, apiAccessToken) {

    // The preceding https:// need to be stripped off before making the call
    apiEndpoint = (apiEndpoint || '').replace('https://', '');
    return new Promise(((resolve, reject) => {

        const options = {
            host: apiEndpoint,
            path: '/v1/endpoints',
            method: 'GET',
            headers: {
                'Content-Type': 'application/json',
                'Authorization': 'Bearer ' + apiAccessToken
            }
        };

        const request = Https.request(options, (response) => {
            response.setEncoding('utf8');
            let returnData = '';
            response.on('data', (chunk) => {
                returnData += chunk;
            });

            response.on('end', () => {
                resolve(JSON.parse(returnData));
            });

            response.on('error', (error) => {
                reject(error);
            });
        });
        request.end();
    }));
};

{
  "name": "agt-mindstorms",
  "version": "1.1.0",
  "description": "A sample skill demonstrating how to use AGT with Lego Mindstorms",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "Amazon Alexa",
  "license": "ISC",
  "dependencies": {
    "ask-sdk-core": "^2.6.0",
    "ask-sdk-model": "^1.18.0",
    "aws-sdk": "^2.326.0",
    "request": "^2.81.0"
  }
}