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Nancy Ghaly
Published © LGPL

P3T Feeder

Dispenses pet food via Alexa (with automatic option)

IntermediateFull instructions providedOver 1 day1,542

Things used in this project

Story

Read more

Custom parts and enclosures

P3T Feeder 3D Model

A 3-dimensional rendering of LEGO P3T Feeder

Schematics

LEGO P3T FEEDER Build Instructions

Step-by-step LEGO P3T FEEDER build instructions

LEGO Foot Stand

Lego Foot Stand

P3T Feeder Schema

Code

model.json

JSON
Alexa json model
{
    "interactionModel": {
        "languageModel": {
            "invocationName": "pet feeder",
            "intents": [
                {
                    "name": "AMAZON.CancelIntent",
                    "samples": []
                },
                {
                    "name": "AMAZON.HelpIntent",
                    "samples": []
                },
                {
                    "name": "AMAZON.StopIntent",
                    "samples": []
                },
                {
                    "name": "AMAZON.NavigateHomeIntent",
                    "samples": []
                },
                {
                    "name": "FeedIntent",
                    "slots": [],
                    "samples": [
                        "Feed the cat",
                        "Feed the dog",
                        "Feed my pet"
                    ]
                },
                {
                    "name": "AutoIntent",
                    "slots": [
                        {
                            "name": "OnOff",
                            "type": "OnOffType"
                        }
                    ],
                    "samples": [
                        "Turn {OnOff} auto feeding",
                        "Turn {OnOff} auto",
                        "Turn {OnOff} auto mode"
                    ]
                }
            ],
            "types": [
                {
                    "name": "OnOffType",
                    "values": [
                        {
                            "name": {
                                "value": "on"
                            }
                        },
                        {
                            "name": {
                                "value": "off"
                            }
                        }
                    ]
                }
            ]
        }
    }
}

index.js

JavaScript
index.js on Alexa platform
/*
 * 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.
*/

// This skill sample demonstrates how to send directives and receive events from an Echo connected gadget.
// This skill uses the Alexa Skills Kit SDK (v2). Please visit https://alexa.design/cookbook for additional
// examples on implementing slots, dialog management, session persistence, api calls, and more.

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

// The audio tag to include background music
const BG_MUSIC = '<audio src="soundbank://soundlibrary/ui/gameshow/amzn_ui_sfx_gameshow_waiting_loop_30s_01"></audio>';

// 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) {

        const request = handlerInput.requestEnvelope;
        const { apiEndpoint, apiAccessToken } = request.context.System;
        const 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
        const endpointId = apiResponse.endpoints[0].endpointId || [];
        Util.putSessionAttribute(handlerInput, 'endpointId', endpointId);

        // Set skill duration to 5 minutes (ten 30-seconds interval)
        Util.putSessionAttribute(handlerInput, 'duration', 10);

        // Set the token to track the event handler
        const token = handlerInput.requestEnvelope.request.requestId;
        Util.putSessionAttribute(handlerInput, 'token', token);

        let speechOutput = "Welcome to Pet Feeder";
        return handlerInput.responseBuilder
            .speak(speechOutput + BG_MUSIC)
            .addDirective(Util.buildStartEventHandler(token,60000, {}))
            .getResponse();
    }
};


// Construct and send a custom directive to the connected gadget with data from
// the FeedIntent.
const FeedIntentHandler = {
    canHandle(handlerInput) {
        return Alexa.getRequestType(handlerInput.requestEnvelope) === 'IntentRequest'
            && Alexa.getIntentName(handlerInput.requestEnvelope) === 'FeedIntent';
    },
    handle: function (handlerInput) {
        const attributesManager = handlerInput.attributesManager;
        let endpointId = attributesManager.getSessionAttributes().endpointId || [];
        let speed = attributesManager.getSessionAttributes().speed || "50";

        // Construct the directive with the payload containing the move parameters
        let directive = Util.build(endpointId, NAMESPACE, NAME_CONTROL,
            {
                type: 'feed',
                command: 'feed',
                speed: speed
            });

        let speechOutput = 'Dispensing food';
        
        return handlerInput.responseBuilder
            .speak(speechOutput + BG_MUSIC)
            .addDirective(directive)
            .getResponse();
    }
};


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

        let onoff = Alexa.getSlotValue(handlerInput.requestEnvelope, 'OnOff');
        if (!onoff) {
            return handlerInput.responseBuilder
                .speak("Can you repeat that?")
                .withShouldEndSession(false)
                .getResponse();
        }
        
        const attributesManager = handlerInput.attributesManager;
        let endpointId = attributesManager.getSessionAttributes().endpointId || [];
        let speed = attributesManager.getSessionAttributes().speed || "50";

        // Construct the directive with the payload containing the move parameters
        let directive = Util.build(endpointId, NAMESPACE, NAME_CONTROL,
            {
                type: 'auto',
                command: onoff,
                speed: speed
            });

        let speechOutput = 'Turning auto feeding ' + onoff;
        
        return handlerInput.responseBuilder
            .speak(speechOutput + BG_MUSIC)
            .addDirective(directive)
            .getResponse();
    }
};

const EventsReceivedRequestHandler = {
    // Checks for a valid token and endpoint.
    canHandle(handlerInput) {
        let { request } = handlerInput.requestEnvelope;
        console.log('Request type: ' + Alexa.getRequestType(handlerInput.requestEnvelope));
        if (request.type !== 'CustomInterfaceController.EventsReceived') return false;

        const attributesManager = handlerInput.attributesManager;
        let sessionAttributes = attributesManager.getSessionAttributes();
        let customEvent = request.events[0];

        // Validate event token
        if (sessionAttributes.token !== request.token) {
            console.log("Event token doesn't match. Ignoring this event");
            return false;
        }

        // Validate endpoint
        let requestEndpoint = customEvent.endpoint.endpointId;
        if (requestEndpoint !== sessionAttributes.endpointId) {
            console.log("Event endpoint id doesn't match. Ignoring this event");
            return false;
        }
        return true;
    },
    handle(handlerInput) {

        console.log("== Received Custom Event ==");
        let customEvent = handlerInput.requestEnvelope.request.events[0];
        let payload = customEvent.payload;
        let name = customEvent.header.name;

        let speechOutput;
        if (name === 'Feeder') {
            speechOutput = payload.speech;
        }
        return handlerInput.responseBuilder
            .speak(speechOutput + BG_MUSIC, "REPLACE_ALL")
            .getResponse();
    }
};
const ExpiredRequestHandler = {
    canHandle(handlerInput) {
        return Alexa.getRequestType(handlerInput.requestEnvelope) === 'CustomInterfaceController.Expired'
    },
    handle(handlerInput) {
        console.log("== Custom Event Expiration Input ==");

        // Set the token to track the event handler
        const token = handlerInput.requestEnvelope.request.requestId;
        Util.putSessionAttribute(handlerInput, 'token', token);

        const attributesManager = handlerInput.attributesManager;
        let duration = attributesManager.getSessionAttributes().duration || 0;
        if (duration > 0) {
            Util.putSessionAttribute(handlerInput, 'duration', --duration);

            // Extends skill session
            const speechOutput = `${duration} minutes remaining.`;
            return handlerInput.responseBuilder
                .addDirective(Util.buildStartEventHandler(token, 60000, {}))
                .speak(speechOutput + BG_MUSIC)
                .getResponse();
        }
        else {
            // End skill session
            return handlerInput.responseBuilder
                .speak("Skill duration expired. Goodbye.")
                .withShouldEndSession(true)
                .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,
        FeedIntentHandler,
        AutoIntentHandler,
        EventsReceivedRequestHandler,
        ExpiredRequestHandler,
        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();

petfeeder.py

Python
ev3dev2 python code
import os
import sys
import time
import logging
import json
import random
import threading

from agt import AlexaGadget
from ev3dev2.led import Leds
from ev3dev2.sound import Sound
from ev3dev2.sensor.lego import ColorSensor
from ev3dev2.motor import OUTPUT_A, MediumMotor, SpeedPercent

# Set the logging level to INFO to see messages from AlexaGadget
logging.basicConfig(level=logging.INFO, stream=sys.stdout, format='%(message)s')
logging.getLogger().addHandler(logging.StreamHandler(sys.stderr))
logger = logging.getLogger(__name__)

class MindstormsGadget(AlexaGadget):
    """
    A Mindstorms gadget that can perform bi-directional interaction with an Alexa skill.
    """

    def __init__(self):
        """
        Performs Alexa Gadget initialization routines and ev3dev resource allocation.
        """
        super().__init__()

        # Robot state
        self.auto_mode = False
        self.feeder = MediumMotor(OUTPUT_A)

        self.sound = Sound()
        self.leds = Leds()
        self.color = ColorSensor()

        # Start threads
        threading.Thread(target=self._autofeed_thread, daemon=True).start()

    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")
        logger.info("{} 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")
        logger.info("{} disconnected from Echo device".format(self.friendly_name))

    def on_custom_mindstorms_gadget_control(self, directive):
        """
        Handles the Custom.Mindstorms.Gadget control directive.
        :param directive: the custom directive with the matching namespace and name
        """
        try:
            payload = json.loads(directive.payload.decode("utf-8"))
            print("Control payload: {}".format(payload), file=sys.stderr)
            control_type = payload["type"]
            if control_type == "feed":
                self._feed_handler()
            elif control_type == "auto":
                self._auto_handler(payload["command"])
        except KeyError:
            print("Missing expected parameters: {}".format(directive), file=sys.stderr)

    def _feed_handler(self):
        #turning 720 to feed
        self.feeder.on_for_degrees(SpeedPercent(30), 720)
    
    def _auto_handler(self, onoff):
        if onoff == "on":
            self.auto_mode = True
        else:
            self.auto_mode = False

    def _autofeed_thread(self):
        """
        Performs random movement when patrol mode is activated.
        """
        while True:
            print(self.color.color)
            if self.color.color == self.color.COLOR_GREEN or self.color.color == self.color.COLOR_BLUE:
                gadget.leds.set_color("LEFT", "RED")
                gadget.leds.set_color("RIGHT", "RED")
            else:
                gadget.leds.set_color("LEFT", "GREEN")
                gadget.leds.set_color("RIGHT", "GREEN")
            if self.auto_mode == True:
                #when the bowl is not green or blue keep dropping feed
                if self.color.color == self.color.COLOR_GREEN or self.color.color == self.color.COLOR_BLUE:
                    self._send_event({'speech':'Food is low, automatic dispensed'})
                    self.feeder.on_for_degrees(SpeedPercent(30), 360)
            time.sleep(1)

    def _send_event(self, payload):
        """
        Sends a custom event to trigger a sentry action.
        :param name: the name of the custom event
        :param payload: the sentry JSON payload
        """
        self.send_custom_event('Custom.Mindstorms.Gadget', "Feeder", payload)


if __name__ == '__main__':

    gadget = MindstormsGadget()

    # Set LCD font and turn off blinking LEDs
    os.system('setfont Lat7-Terminus12x6')
    gadget.leds.set_color("LEFT", "BLACK")
    gadget.leds.set_color("RIGHT", "BLACK")

    # Startup sequence
    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")

petfeeder.ini

INI
ini file for ev3dev2
# 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.

[GadgetSettings]
amazonId = [amazonid]
alexaGadgetSecret = [alexaGadgetSecret]

[GadgetCapabilities]
Custom.Mindstorms.Gadget = 1.0

p3tfeeder.zip

Python
Entire code base for P3T Feeder, which includes ev3dev2 python code and server alexa javascript code
No preview (download only).

Credits

Nancy Ghaly

Nancy Ghaly

1 project • 1 follower

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