Published August 11, 2019 © CC BY

Boo Nought (Raffle Device)

A motion-activated raffle device that can draw numbers or names. Users can specify the range of numbers or the list of names through WiFi.

IntermediateFull instructions provided3 days839

Things used in this project

Hardware components

Espressif Wemos D1 Mini

SparkFun Triple Axis Accelerometer and Gyro Breakout - MPU-6050

Adafruit Standard LCD - 16x2 White on Blue

Rotary potentiometer (generic)

jlcpcb

Slide Switch

Battery Holder, 18650 x 2

18650

Story

In class, I use to raffle the names of students and the "lucky ones" get to answer an assignment or quiz on the board. I usually just ask them to write their names on a small piece of paper or use a software on my computer. One day it dawned on me: what if I create a device that raffle the names by shaking it?

The device is powered by a WeMos D1 Mini and an MPU6050 IMU. I could have just used a vibration sensor to detect motion but I found it too sensitive. With the MPU6050, I could adjust the "shake sensitivity" and maybe, in the future, make the device respond to shakes in different directions.

Choosing the WeMos D1 Mini stemmed from the fact that I don't want the names or numbers to be hard coded. The names or numbers to be drawn should be entered by the user without having to change the code. So, I created a simple web interface that a user can access if he or she is connected to the WeMos D1's access point. The names or numbers are then stored in the microcontroller's EEPROM.

I know that EEPROM size is limited so the number of names that can be stored is small (4096 bytes so around 4096 letters). I plan to add an SD card slot in the future.

Code

Boo Nought Sketch

/*
 * Draw Lots Sketch
 * by Roland Pelayo
 * 
 * A random number/name generator using ESP8266
 * 
 * Number range and names can be generated using ESP8266 web server. The range of numbers and/or names are stored in EEPROM
 * 
 * Required libraries:
 *  > ESP8266 Arduino Core
 *  > MPU6050 for ESP8266
 *  > Liquid Crystal
 *  > EEPROM
 */


#include <Wire.h>
#include <ESP8266WiFi.h> 
#include <MPU6050.h>
#include <WiFiClient.h>
#include <ESP8266WebServer.h>
#include <EEPROM.h>
#include <stdio.h>
#include <string.h>

//#ifndef APSSID
#define APSSID "drawlots"
#define APPSK  "123456"
//#endif

/* Set these to your desired credentials. */
const char *ssid = APSSID;
const char *password = APPSK;

ESP8266WebServer server(80);

MPU6050 mpu;
int SCL_PIN=D6;
int SDA_PIN=D5;

#include <LiquidCrystal.h>
const int rs = D7, en = D8, d4 = D1, d5 = D2, d6 = D3, d7 = D4;
int sw = D0;

LiquidCrystal lcd(rs, en, d4, d5, d6, d7);
long randNumber,previousNumber;
bool stillShaking = false;
bool serverSetupDone = false;
int activity_counter;
int old_act_counter;
int sensitivity = 4;

byte page = 0;    //for checking which screen to display
byte _mode = 0; //for checking whice mode (names or numbers)
  
const char MAIN_PAGE[] PROGMEM = R"=====(
<!DOCTYPE html>
<html>
<body>
<style>
  div{
    text-align: center;
  }
  body{
    font-family: Helvetica, Sans-serif;
  }
  button{
    font-size: 12;
    margin: 2px,2px,2px,2px;
  }
</style>
<div id="header">
  <h1>Draw Lots</h1>
  <h2>by Roland Pelayo</h2>
</div>
<div id="form">
 <h3>Choose option:</h3>
 <div id="buttons">
  <form action="/number">
    <button type="submit">Random Number</button>
  </form>
  &nbsp;
  <form action="/name">
   <button type="submit">Random Name</button>
  </form>
 </div>
</div>
</body>
</html>
)=====";

const char NUMBER_PAGE[] PROGMEM = R"=====(
<!DOCTYPE html>
<html>
<body>

<style>
  div{
    text-align: center;
  }
  body{
    font-family: Helvetica, Sans-serif;
  }
  button{
    font-size: 12;
    margin: 2px,2px,2px,2px;
  }
</style>

<div id="header">
<h1>Random Number Generator</h1>
</div>
<div id="form">
 <form action="/save_numbers">
  <h4>Enter minimum number</h4>
  <input type="text" name="minNumber">
  <h4>Enter maximum number</h4>
  <input type="text" name="maxNumber">
  <p></p>
  <input type="submit" value="Save"></input>
 </form>
 </div>
 </body>
</html>
)=====";

const char NAMES_PAGE[] PROGMEM = R"=====(
<!DOCTYPE html>
<html>
<body>

<style>
  div{
    text-align: center;
  }
  body{
    font-family: Helvetica, Sans-serif;
  }
  button{
    font-size: 12;
    margin: 2px,2px,2px,2px;
  }
</style>

 <div id="header">
 <h1>Random Names Generator</h1>
 </div>
 <div id="form">
  <form action="/save_names">
   <h4>Enter Names separated by comma</h4>
   <input type="text" name="names">
   <input type="submit" value="Submit"></input>
  </form>
 </div>
 </body>
</html>
)=====";

void handleRoot() {
  String st = MAIN_PAGE;
  server.send(200, "text/html", st);
}

void handleNumber(){
  String st = NUMBER_PAGE;
  server.send(200,"text/html", st);
}

void handleNames(){
  String st = NAMES_PAGE;
  server.send(200,"text/html", st);
}

void handleSaveNumbers(){
  String minNum = server.arg("minNumber");
  int minNumber = minNum.toInt();
  String maxNum = server.arg("maxNumber");
  int maxNumber = maxNum.toInt();
  
  EEPROM.write(0,minNumber);
  EEPROM.write(1,maxNumber);
  EEPROM.write(2,1);
  EEPROM.commit();
  String s = "<a href='/'>Home</a>";
  server.send(200,"text/html",s);
}

void handleSaveNames(){
  String names = server.arg("names");
  Serial.println(names);
  int counter;
  counter = countCommas(names)+1;
  Serial.print("Names: ");
  Serial.println(counter);
  EEPROM.write(2,0);
  EEPROM.write(3,counter);  //store number of names
  EEPROM.commit();
  String _names [20];
  for(int i = 0;i<counter;i++){
    _names[i] = getValue(names,',',i);
    writeString((i+1)*10,_names[i]);
  }

  String s2[20];
  for(int j=0;j<counter;j++){
    s2[j] = read_String((j+1)*10);
    Serial.println(s2[j]);
  }
  String s = "<a href='/'>Home</a>";
  server.send(200,"text/html",s);
}

//Function to write string to EEPROM
void writeString(char add, String data){
  int _size = data.length();
  int i;
  for(i = 0;i<_size;i++){
    EEPROM.write(add+i,data[i]);
  }
  EEPROM.write(add+_size,'\0');
  EEPROM.commit();
}

//Function to read string from EEPROM
String read_String(char add){
  int i;
  char data[100];
  int len=0;
  unsigned char k;
  k=EEPROM.read(add);
  while(k!= '\0' && len<500){
    k=EEPROM.read(add+len);
    data[len]=k;
    len++;
  }
  data[len]='\0';
  return String(data);
}

//Function to count commas, and consequently, the number of names
int countCommas(String s){
  byte counter = 0;
  int stringLength;
  byte index,newIndex;
  stringLength = s.length();
 // Serial.print("The string is: ");
 // Serial.println(s);
 // Serial.print("The string length is: ");
 // Serial.println(stringLength);
  index = s.indexOf(',');
 // Serial.print("Index of first comma is: ");
 // Serial.println(index);
  while(index < stringLength){
      newIndex = s.indexOf(',',index+1);
      if(newIndex > stringLength){
        break;
      }
      if(newIndex != -1){
   //     Serial.println("Next comma found! "); 
        counter++;
   //     Serial.print("Index of next comma is: ");
   //     Serial.println(newIndex);
   //     Serial.print("Commas found: ");
   //     Serial.println(counter);
      }else{
        break;
      }
      index = newIndex;
  }
  //Serial.print("The number of commas is: ");
  //Serial.println(counter+1);
  return counter+1;
}

//Function to split string with separator (comma, in this case)
String getValue(String data, char separator, int index){
  int found = 0;
  int strIndex[] = {0,-1};
  int maxIndex = data.length()-1;

  for(int i=0;i<=maxIndex && found <=index; i++){
    if(data.charAt(i)==separator || i==maxIndex){
      found++;
      strIndex[0]=strIndex[1]+1;
      strIndex[1]=(i==maxIndex)?i+1:i;
    }
    if(i==maxIndex && found == index){
      strIndex[0]= strIndex[1]+1;
      strIndex[1]= maxIndex;
      return data.substring(strIndex[0],strIndex[1]);
    }
  }
  return found>index ? data.substring(strIndex[0],strIndex[1]) : "";
}
  
void setup() 
{
  lcd.begin(16,2);
  delay(1);
  Serial.begin(9600);
  randomSeed(analogRead(0));

  pinMode(sw,INPUT);
  
  lcd.setCursor(0,0);
  lcd.print("Initializing");
  
  EEPROM.begin(512);

  initMPU();
}

void initMPU(){
  while(!mpu.beginSoftwareI2C(SCL_PIN,SDA_PIN,MPU6050_SCALE_2000DPS, MPU6050_RANGE_16G))
  {
    lcd.print("IMU Error!");
    delay(500);
  }
  delay(1000);
  lcd.clear();
  
  mpu.setAccelPowerOnDelay(MPU6050_DELAY_3MS);
  mpu.setIntFreeFallEnabled(false);  
  mpu.setIntZeroMotionEnabled(false);
  mpu.setIntMotionEnabled(false);
  mpu.setDHPFMode(MPU6050_DHPF_5HZ);
  mpu.setMotionDetectionThreshold(2);
  mpu.setMotionDetectionDuration(5);
  mpu.setZeroMotionDetectionThreshold(4);
  mpu.setZeroMotionDetectionDuration(2);  
}

void serverMode(){
  lcd.setCursor(0,0);
  lcd.print("Server mode     ");
  delay(1000);
  lcd.setCursor(0,0);
  lcd.print("Configuring AP  ");
  /* You can remove the password parameter if you want the AP to be open. */
  WiFi.softAP(ssid, password);

  IPAddress myIP = WiFi.softAPIP();
  
  lcd.setCursor(0,0);
  lcd.print("IP: ");
  lcd.print(myIP);
  server.on("/", handleRoot);
  server.on("/number",handleNumber);
  server.on("/name",handleNames);
  server.on("/save_numbers",handleSaveNumbers);
  server.on("/save_names",handleSaveNames);
  server.begin();
  lcd.setCursor(0,1);
  lcd.print("Server started  ");
  serverSetupDone = true;
}

void loop()
{
  if(digitalRead(sw) == 1){
    delay(500);
    if(serverSetupDone == false){
      serverMode();
    }else{ 
      server.handleClient();
    }
  }else{
    delay(500);
    gameMode();
  }
}

void gameMode(){
  WiFi.forceSleepBegin();
  Serial.print("Page: ");
  Serial.println(page);
  int stage = checkMotion();
  if(stage == 1 && page == 0){
      startCheckMode();  
  }else if(stage == 1 && page == 1){
      startRandomizer();
  }else if(stage == 0 && page == 0){
    //lcd.clear();
    lcd.setCursor(0,0);
    lcd.print("Shake device to  ");
    lcd.setCursor(0,1);
    lcd.print("start            ");
  }else if(stage == 0 && page == 1){
    lcd.setCursor(0,0);
    lcd.print("Shake device to  "); 
    lcd.setCursor(0,1);
    lcd.print("draw             ");
  }else{;}
  
  delay(500);
}

int checkMotion(){

  Activites act = mpu.readActivites();
  
  if(act.isActivity == 1){
    activity_counter++;
    Serial.print("Activity: ");
    Serial.println(activity_counter);
    if(activity_counter > 1000){
      activity_counter = 0;
    }
    if(activity_counter - old_act_counter == sensitivity){
      old_act_counter = activity_counter;
      return 1;
    }else{
      return 0;
    }
  }else{
    return 0;
  }
}
/*
int checkMotion(){
  //Vector rawAccel = mpu.readRawAccel();
  int count = 0;
  bool doneShaking = false;
  Activites act = mpu.readActivites();
  
  if(act.isActivity == 1 && act.isInactivity == 0){
    delay(500);
    Activites act = mpu.readActivites();
    if(act.isActivity == 1 && act.isInactivity == 0){
      stillShaking = true;
      lcd.clear();
      count++;
      if(count < 3){
        lcd.setCursor(0,0);
        lcd.print("Shake & shake!");
        lcd.setCursor(count,1);
        lcd.print('.');
        return 2;            
      }else if(count == 3){
        count = 0;
        return 3;
      }
    }else{
      return 0;
    }
   }else{
      return 0;
   }
  /*
  delay(1000);
  while(stillShaking == true){
      Activites act = mpu.readActivites();
      delay(500);
      if(act.isActivity && !act.isInactivity){
        stillShaking = true;
        count++;
        lcd.setCursor(0,0);
        lcd.print("Shake & shake!");
        lcd.setCursor(count,1);
        lcd.print('.');      
        if(count==3){
          doneShaking = true;
          stillShaking = false;
          count == 0;
          break;
        }   
        
      }
      delay(200);
  }
 if(doneShaking == true){
  return 1;
 } 
}*/

void startCheckMode(){
  _mode = EEPROM.read(2);
  if(_mode == 0){
    lcd.setCursor(0,0);
    lcd.print("Drawing Names    ");
    lcd.setCursor(0,1);
    lcd.print("                 ");
  }else if(_mode == 1){
    lcd.setCursor(0,0);
    lcd.print("Drawing Numbers  ");
    lcd.setCursor(0,1);
    lcd.print("                 ");
  }else{;}
  page = 1;
}

bool startRandomizer(){
  if(_mode == 1){
    Serial.println("Draw random numbers");
    byte data1,data2;
    data1 = EEPROM.read(0);
    data2 = EEPROM.read(1);
    
    int minNum = (int)data1;
    int maxNum = (int)data2;
    
    randNumber = random(minNum,maxNum);
    while(randNumber == previousNumber){
      randNumber = random(minNum,maxNum);
    }
    lcd.setCursor(0,0);
    lcd.print("Lucky number is: ");
    lcd.setCursor(0,1);
    lcd.print(randNumber);
    previousNumber = randNumber;
 
    if(randNumber > 9){
      lcd.print("               ");
    }else{
      lcd.print("              ");
    }
  }
  else if(_mode == 0){
    Serial.println("Draw random names");
    byte count;
    count = EEPROM.read(3);
    
    String names[20];

    for(int i=0;i<(int)count;i++){
      names[i] = read_String((i+1)*10);
    }
  
    randNumber = random(1,(int)count);
    while(randNumber == previousNumber){
      randNumber = random(1,(int)count);
    }
    lcd.setCursor(0,0);
    lcd.print("Lucky Person is: ");
    lcd.setCursor(0,1);
    lcd.print(names[randNumber]);
    previousNumber = randNumber;
  }
    delay(5000);
    page = 0;
}

Credits

Roland Pelayo

6 projects • 11 followers

I am an electronics engineer working as a college professor and author of Teach Me Microcontrollers! - a blog about PICs, Arduino, etc.

Boo Nought (Raffle Device)

Things used in this project

Hardware components

Story

Schematics

Boo Nought Fritzing Diagram

Boo Nougth Eagle Schematic

Code

Boo Nought Sketch

Credits

Roland Pelayo

Comments

Embed the widget on your own site

Boo Nought (Raffle Device)

Boo Nought (Raffle Device)

Things used in this project

Hardware components

Story

Schematics

Boo Nought Fritzing Diagram

Boo Nougth Eagle Schematic

Code

Boo Nought Sketch

Credits

Roland Pelayo

Comments

Related channels and tags