Sunday, April 30, 2017

Building a Custom Strain Gauge with Electric Paint

In this video we look at how we can use Bare Conductive's Electric Paint to create a custom strain gauge.




/*
 * This code was written for a video on the ForceTronics YouTube channel. This code is public domain and can be used and modified by anybody at your own risk
 */

#include <Average.h> //Call average library

void setup() {
  Serial.begin(57600);
  analogReadResolution(12); //Set Arduino Zero ADC to 12 bits
  for(int i=0;i<4;i++) analogRead(A0); //burn a couple readings since we changed ADC setting
  Average<int> ave(10);
}

void loop() {
  delay(100);
  Average<int> ave(10); //Create average object
  for (int i=0; i<10;i++) ave.push(analogRead(A0) - 2700); //get 10 readings and subtract most of the value off to look at small changes
  Serial.println(ave.mean()); //average the 10 readings together
}

Thursday, April 6, 2017

Home Automation with the Arduino and the Amazon Echo Part 2

In this video series we look at how to use Arduino (ESP8266) and the Amazon Echo to do voice controlled home automation.






Link to project material on GitHub: https://github.com/ForceTronics/Arduino_Echo_Home_Automation

//************************************ESP8266 Arduino code*********************
/*
 This sketch was created for a video series called Home Automation with the Arduino and the Amazon Echo Part 2 
 That was presented on the ForceTronics YouTube Channel. This code is public domain for anybody to use or modify at your own risk
 Note that this code was leveraged from a Sparkfun example on using their cloud service Phant
 */

// Include the ESP8266 WiFi library
#include <ESP8266WiFi.h>
// Include the SparkFun Phant library.
#include <Phant.h>

//Set your network name and password
const char WiFiSSID[] = "NetworkName"; //your wifi network name goes here
const char WiFiPSK[] = "NetworkPassword"; //your wifi password goes here

//define constants for pin control and node number
const int light = 4; //NodeMCU GPIO 4 pin is connected to the WiFi AC Switch control
const char parseKey[] = "stamp"; //This is used to parse through data from Phant to find light setting

//declare phant address and security keys
const char PhantHost[] = "data.sparkfun.com";
const char gPublicKey[] = "YourPublicKey"; //your phant public key goes here
const char gPrivateKey[] = "YourPrivateKey"; //your phant private key goes here

//specify the rate that you post data to cloud
const unsigned long postRate = 1000;
unsigned long lastPost = 0;

void setup() 
{
  initHardware(); //setup arduino hardware
  connectWiFi(); //Connect your WiFi network
  digitalWrite(LED_BUILTIN, HIGH); //turn on LED
}

void loop() 
{ //loop until it is time to post data to phant cloud, variable "postRate" defines the interval in milli seconds
  if (lastPost + postRate <= millis())
  {
    if (getFromPhant()) lastPost = millis(); //get data from Phant
    else lastPost = millis(); //Even if we fail delay whole cycle before we try again
  }
}

//function used to connect to WiFi network
void connectWiFi()
{
  byte ledStatus = LOW;
  // Set WiFi mode to station (as opposed to AP or AP_STA)
  WiFi.mode(WIFI_STA);
  // WiFI.begin([ssid], [passkey]) initiates a WiFI connection
  // to the stated [ssid], using the [passkey] as a WPA, WPA2,
  // or WEP passphrase.
  WiFi.begin(WiFiSSID, WiFiPSK);
  
  // Use the WiFi.status() function to check if the ESP8266
  // is connected to a WiFi network.
  while (WiFi.status() != WL_CONNECTED)
  {
    // Blink the LED
    digitalWrite(LED_BUILTIN, ledStatus); // Write LED high/low
    ledStatus = (ledStatus == HIGH) ? LOW : HIGH;
    
    // Delays allow the ESP8266 to perform critical tasks
    // defined outside of the sketch. These tasks include
    // setting up, and maintaining, a WiFi connection.
    delay(100);
  }
}

//function that sets up some initial hardware states
void initHardware()
{
  pinMode(light, OUTPUT); //turn light off at startup
  digitalWrite(light, LOW);
}

//function that handles getting data from phant cloud
int getFromPhant()

 //Set phant data
 Phant phant(PhantHost, gPublicKey, gPrivateKey);
  
  WiFiClient client; //Create client object to communicate with the phant server

  if (!client.connect(PhantHost, 80)) { //Attempt to connect to phant server using port 80
    // If we fail to connect, return 0.
    return 0;
  }

  //Get data from phant cloud
    client.print(phant.get()); 
    client.println();
   int cTrack = 0; //variable that tracks count to spell stamp
   bool match = false; //tracks when we have a match with "stamp" and we can then get control data
   int pCount = 0; //variable used to track when we have control data
   while(1) { //loop until we get data and server closes connection
    if (client.available()) { //if data is available from phant server
      char c = client.read(); //read a bite of data from server
      if(!match) { //if true than we have not found the word "stamp" so keep looking
        if(c == parseKey[cTrack]) //check if we have a character match with word "stamp"
        {
          if(cTrack == (sizeof(parseKey)-2)) match = true; //if true it means we found a match for "stamp" in data from phant cloud
          cTrack++; //iterate this count if a character match was found
        }
        else { //if true means no character match so reset count
          cTrack = 0;
        }
      }
      else { //if true it means we found a match to "stamp" and we are ready to get control data
        
        if(pCount == 1) { //if true we are at the point in the data to read control data for node oen
          int dControl = c - '0'; //convert char data to an int by subtract an ASCII zero
          if(dControl == 1 | dControl == 0) digitalWrite(light, dControl); //make sure data is a one or zer and set LED pin with it
        }
        pCount++; //iterate the parse counter
      }
    }

    // if the server's disconnected, stop the client:
    if (!client.connected()) {
      client.stop(); //stop client, if you don't have this you will create too many clients and server won't let you connect anymore
      break; //This is how we get out of the loop
    }
   }
  
  return 1; // Return success
}

  

Sunday, April 2, 2017

Home Automation with the Arduino and the Amazon Echo Part 1

In this video series we look at how to use Arduino (ESP8266) and the Amazon Echo to do voice controlled home automation.



//*******************json file for Alexa Skill*****************
{
  "intents": [
    {
      "intent": "TurnLightOn"
    },
    {
      "intent": "TurnLightOff"
    }
  ]
}

//********************java script code for Lambda Function*************************
var https = require('https') //include https

exports.handler = (event, context) => {

  try {

    if (event.session.new) {
      // New Session
      console.log("NEW SESSION") //log this for debugging
    }

    switch (event.request.type) {

      case "LaunchRequest":
        // Launch Request
        console.log(`LAUNCH REQUEST`)
        context.succeed(
          generateResponse(
            buildSpeechletResponse("Welcome to the ForceTronics Home Automation Skill, say turn light on or turn light off", true), //response for Alexa if you just call the skill without intent
            {}
          )
        )
        break;

      case "IntentRequest":
        // Intent Request
        console.log(`INTENT REQUEST`)

        switch(event.request.intent.name) { //switch statement to select the right intent
          case "TurnLightOn":
          var endpoint = "https://data.sparkfun.com/input/YourPublicKey?private_key=YourPrivateKey&lightstate=1" //https string to log data to phant phant
          https.get(endpoint, function (result) { //use https get request to send data to phant
          console.log('Success, with: ' + result.statusCode);
          context.succeed(
           generateResponse( //if you succeeded allow Alexa to tell you state of light
                buildSpeechletResponse("The light is turned on", true),
                {}
            )
          )
          }).on('error', function (err) {
            console.log('Error, with: ' + err.message);
            context.done("Failed");
          });
            break;

          case "TurnLightOff": //the turn light off intent
            var endpoint2 = "https://data.sparkfun.com/input/YourPublicKey?private_key=YourPrivateKey&lightstate=0" // phant string to set light state to off
            https.get(endpoint2, function (result) {
            console.log('Success, with: ' + result.statusCode);
            context.succeed(
                generateResponse( //Alexa response if successful
                 buildSpeechletResponse("The light is turned off", true),
                    {}
                )
            )
            }).on('error', function (err) {
            console.log('Error, with: ' + err.message);
            context.done("Failed");
            });
            break;

          default:
            throw "Invalid intent"
        }

        break;

      case "SessionEndedRequest":
        // Session Ended Request
        console.log(`SESSION ENDED REQUEST`)
        break;

      default:
        context.fail(`INVALID REQUEST TYPE: ${event.request.type}`)

    }

  } catch(error) { context.fail(`Exception: ${error}`) }

}

// builds an Alexa response
buildSpeechletResponse = (outputText, shouldEndSession) => {

  return {
    outputSpeech: {
      type: "PlainText",
      text: outputText
    },
    shouldEndSession: shouldEndSession
  }

}

//plays Alexa reponse
generateResponse = (speechletResponse, sessionAttributes) => {

  return {
    version: "1.0",
    sessionAttributes: sessionAttributes,
    response: speechletResponse
  }

}