Smart Blind Opener And LEarning tool

ENGR-4960

Fall 2020

Neil Koul

Features

Must be able to use IoT
ESP 8266 with a low power mode
Uses a cheap servo motor

Goals

3-D printable parts to keep cost low
Be able to control it through Google Home
Design a PCB to be expandable to learning platform

Implementation

Design

Breadboard design, esp8266 and a servo
Draw up Schematic in EDA software
Order PCB
Integrate with Automation

BreadBoard

ESP8266 DevBoard

Servo with Continuous rotation

Schematic

PCB

BRacket Design

INtegration

There are a few steps to get the device added

Adafruit.io

Adafruit.io is a free IoT service
Easily accessible Library for a multitude of devices
Easy to program with as well

Programming

Get Adafruit IO Key
Add to program
Program device to trigger serve rotation

CODE

#include <ESP8266WiFi.h>
#include <Servo.h>
#include "Adafruit_MQTT.h"
#include "Adafruit_MQTT_Client.h"

#define WIFI_SSID "Wifi"
#define WIFI_PASS "superStrongPassword"

#define MQTT_SERV "io.adafruit.com"
#define MQTT_PORT 1883
#define MQTT_NAME "nkoul"
#define MQTT_PASS "1337_hack3r"

Servo servo;

WiFiClient client;
Adafruit_MQTT_Client mqtt(&client, MQTT_SERV, MQTT_PORT, MQTT_NAME, MQTT_PASS);

Adafruit_MQTT_Subscribe onoff = Adafruit_MQTT_Subscribe(&mqtt, MQTT_NAME "/f/onoff");

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);

  //Connect to WiFi
  Serial.print("\n\nConnecting Wifi... ");
  WiFi.begin(WIFI_SSID, WIFI_PASS);
  while (WiFi.status() != WL_CONNECTED)
  {
    delay(500);
  }

  Serial.println("OK!");

  //Subscribe to the onoff topic
  mqtt.subscribe(&onoff);

  pinMode(LED_BUILTIN, OUTPUT);

}

void loop() {
  //Connect/Reconnect to MQTT
  MQTT_connect();

  //Read from our subscription queue until we run out, or
  //wait up to 5 seconds for subscription to update
  Adafruit_MQTT_Subscribe * subscription;
  while ((subscription = mqtt.readSubscription(5000)))
  {
    //If we're in here, a subscription updated...
    if (subscription == &onoff)
    {
      //Print the new value to the serial monitor
      Serial.print("onoff: ");
      Serial.println((char*) onoff.lastread);

      //If the new value is  "ON", turn the light on.
      //Otherwise, turn it off.
      if (!strcmp((char*) onoff.lastread, "ON"))
      {
        //active low logic
        digitalWrite(LED_BUILTIN, LOW); 
        servo.attach(2);
        servo.write(90);
        servo.detach();
      }
      else
      {
        digitalWrite(LED_BUILTIN, HIGH);
        servo.attach(2);
        servo.write(90);
        servo.detach();
      }
    }
  }
}

void MQTT_connect() 
{
  int8_t ret;
  // Stop if already connected
  if (mqtt.connected())
  {
    return;
  }

  Serial.print("Connecting to MQTT... ");
  uint8_t retries = 3;
  while ((ret = mqtt.connect()) != 0) // connect will return 0 for connected
  { 
    Serial.println(mqtt.connectErrorString(ret));
    Serial.println("Retrying MQTT connection in 5 seconds...");
    mqtt.disconnect();
    delay(5000);  // wait 5 seconds
    retries--;
    if (retries == 0) 
    {
      // basically die and wait for WDT to reset me
      while (1);
    }
  }
  Serial.println("MQTT Connected!");
}

ifttt

IFTTT is a free service that you can create custom automations on
Able to connect multiple different services together

Expansion

This is just one of the many projects that can be done with an ESP8266

Education

The ESP8266 makes a great and cheap platform for teaching IoT to students

POssible Projects

IoT Temperature sensor
IoT Servo
IoT Sensors
IoT Relays
IoT Lights

IOT Temperature sensor

Cost: $3 for senor, $4 for ESP8266, Total $7

#include <ESP8266WebServer.h>
#include <Wire.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_BME280.h>

#define SEALEVELPRESSURE_HPA (1013.25)

Adafruit_BME280 bme;

float temperature, humidity, pressure, altitude;

/*Put your SSID & Password*/
const char* ssid = "YourNetworkName";
const char* password = "YourPassword";

ESP8266WebServer server(80);              
 
void setup() {
  Serial.begin(115200);
  delay(100);
  
  bme.begin(0x76);   

  Serial.println("Connecting to ");
  Serial.println(ssid);

  //connect to your local wi-fi network
  WiFi.begin(ssid, password);

  //check wi-fi is connected to wi-fi network
  while (WiFi.status() != WL_CONNECTED) {
  delay(1000);
  Serial.print(".");
  }
  Serial.println("");
  Serial.println("WiFi connected..!");
  Serial.print("Got IP: ");  Serial.println(WiFi.localIP());

  server.on("/", handle_OnConnect);
  server.onNotFound(handle_NotFound);

  server.begin();
  Serial.println("HTTP server started");

}
void loop() {
  server.handleClient();
}

void handle_OnConnect() {
  temperature = bme.readTemperature();
  humidity = bme.readHumidity();
  pressure = bme.readPressure() / 100.0F;
  altitude = bme.readAltitude(SEALEVELPRESSURE_HPA);
  server.send(200, "text/html", SendHTML(temperature,humidity,pressure,altitude)); 
}

void handle_NotFound(){
  server.send(404, "text/plain", "Not found");
}

String SendHTML(float temperature,float humidity,float pressure,float altitude){
  String ptr = "<!DOCTYPE html> <html>\n";
  ptr +="<head><meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0, user-scalable=no\">\n";
  ptr +="<title>ESP8266 Weather Station</title>\n";
  ptr +="<style>html { font-family: Helvetica; display: inline-block; margin: 0px auto; text-align: center;}\n";
  ptr +="body{margin-top: 50px;} h1 {color: #444444;margin: 50px auto 30px;}\n";
  ptr +="p {font-size: 24px;color: #444444;margin-bottom: 10px;}\n";
  ptr +="</style>\n";
  ptr +="</head>\n";
  ptr +="<body>\n";
  ptr +="<div id=\"webpage\">\n";
  ptr +="<h1>ESP8266 Weather Station</h1>\n";
  ptr +="<p>Temperature: ";
  ptr +=temperature;
  ptr +="&deg;C</p>";
  ptr +="<p>Humidity: ";
  ptr +=humidity;
  ptr +="%</p>";
  ptr +="<p>Pressure: ";
  ptr +=pressure;
  ptr +="hPa</p>";
  ptr +="<p>Altitude: ";
  ptr +=altitude;
  ptr +="m</p>";
  ptr +="</div>\n";
  ptr +="</body>\n";
  ptr +="</html>\n";
  return ptr;
}