Jonathan Tindal
Published © GPL3+

No Candy For YOU!

A prank candy bowl that senses when someone tries to reach for a piece and automatically empties before they can get one.

IntermediateFull instructions provided12 hours789

Things used in this project

Hardware components

Arduino UNO & Genuino UNO
Arduino UNO & Genuino UNO
×1
Ultrasonic Sensor - HC-SR04 (Generic)
Ultrasonic Sensor - HC-SR04 (Generic)
×1
Adafruit 9g Micro Servo
×1
SparkFun Piezo Speaker
×1
SparkFun Mini Pushbutton Switch
×1
General Purpose Transistor NPN
General Purpose Transistor NPN
×1
Resistor 1k ohm
Resistor 1k ohm
×1
Resistor 10k ohm
Resistor 10k ohm
×1
Breadboard (generic)
Breadboard (generic)
×1
Jumper wires (generic)
Jumper wires (generic)
×1
9V Battery Clip
9V Battery Clip
×1
9V battery (generic)
9V battery (generic)
×1

Software apps and online services

Arduino IDE
Arduino IDE
circuito.io
circuito.io

Hand tools and fabrication machines

Hot glue gun (generic)
Hot glue gun (generic)
Hobby Knife

Story

Read more

Schematics

Wiring Diagram from Circuit.io

So nice to have this auto-generated by circuit.io!
Circuit io wiringdiagram 5amxa7ubls

Code

NoCandy.ino

C/C++
My Candy Bowl prank Arduiono firmware code
// Include Libraries
#include "Arduino.h"
#include "NewPing.h"
#include "PiezoSpeaker.h"
#include "Button.h"
#include "Servo.h"


// Pin Definitions
#define HCSR04_PIN_TRIG	3
#define HCSR04_PIN_ECHO	4
#define PIEZOSPEAKER_PIN_SIG	5
#define PUSHBUTTON_PIN_1	6
#define SERVO9G_PIN_SIG	2

// Global variables and defines
unsigned int piezoSpeakerNNBBLength          = 6;                                                      
unsigned int piezoSpeakerNNBBMelody[]        = {NOTE_C4, NOTE_C4, NOTE_A3, NOTE_D4, NOTE_C4, NOTE_A3}; 
unsigned int piezoSpeakerNNBBNoteDurations[] = {4      ,4      , 4      , 4      , 2      , 4      }; 
unsigned int piezoSpeakerArmedLength          = 3;                                                    
unsigned int piezoSpeakerArmedMelody[]        = {NOTE_C5, NOTE_C5, NOTE_C5}; 
unsigned int piezoSpeakerArmedNoteDurations[] = {4      ,4      , 4      }; 
const int servo9gClosedPosition   = 20;  //Starting position - closed
const int servo9gOpenPosition = 110; //Trap door open position
const int triggerDistance = 10;

// Constructors
Servo servo9g;
NewPing hcsr04(HCSR04_PIN_TRIG,HCSR04_PIN_ECHO);
PiezoSpeaker piezoSpeaker(PIEZOSPEAKER_PIN_SIG);
Button pushButton(PUSHBUTTON_PIN_1);




// define vars for testing menu
#define TIMEOUT 10000       //define timeout of 10 sec
char menuOption = 0;
long time0;

/* This code sets up the essentials for your circuit to work. It runs first every time your circuit is powered with electricity. */
void setup() {
    // Setup Serial which is useful for debugging
    // Use the Serial Monitor to view printed messages
    Serial.begin(9600);
    while (!Serial) ; // wait for serial port to connect. Needed for native USB
    Serial.println("start");
    
    pushButton.init();
    servo9g.attach(SERVO9G_PIN_SIG);
    servo9g.write(servo9gClosedPosition);
    delay(500);
    servo9g.detach();
}

void loop() {

    bool triggered=false;
    bool armed=true;
    
    //Keep checking distance meter - if something close then open servo if not then back to wait
    while (triggered==false) {
        int hcsr04Dist = hcsr04.ping_cm();
        
        if((hcsr04Dist != 0) && (hcsr04Dist < triggerDistance)) {
          triggertrap(hcsr04Dist);
          triggered = true;
          armed = false;
        }
        else {
          //Serial.print(F("Distance: ")); Serial.print(hcsr04Dist); Serial.println(F("[cm]")); // print triggered distance for debug
          delay(100);
        }
    }
    

    //Wait for reset signal
    while (triggered==true) {
        bool pushButtonVal = pushButton.read();
    
    
        if(pushButtonVal) {
          resettrap();
          triggered = false;
        }
       else {
          delay(100);
        }
    }

    //Wait for second button press to signal that the trap is ready to arm again
    while (armed==false) {
        bool pushButtonVal = pushButton.read();
    
        if(pushButtonVal) {
          armtrap();
          armed = true;
        }
       else {
          delay(100);
        }
    }
}

// This section is used to trigger the trap and play music
void triggertrap(int triggerDistance)
{
    //Open servo trap
    Serial.print(F("Trigger Distance: ")); Serial.print(triggerDistance); Serial.println(F("[cm]")); // print triggered distance for debug
    servo9g.attach(SERVO9G_PIN_SIG);         // 1. attach the servo to correct pin to control it.
    servo9g.write(servo9gOpenPosition);      // 2. turns servo to open position. 
    delay(1000);                              // 3. wait 100 milliseconds
    servo9g.detach();                        // 4. detach the servo

    //Play Music- The Speaker will play the Nanny Nanny Boo Boo tune x2:P
    piezoSpeaker.playMelody(piezoSpeakerNNBBLength, piezoSpeakerNNBBMelody, piezoSpeakerNNBBNoteDurations);
    delay(250); 
    piezoSpeaker.playMelody(piezoSpeakerNNBBLength, piezoSpeakerNNBBMelody, piezoSpeakerNNBBNoteDurations); 
    
    delay(500);
}

void resettrap()
{
    //Close servo trap
    servo9g.attach(SERVO9G_PIN_SIG);         // 1. attach the servo to correct pin to control it.
    servo9g.write(servo9gClosedPosition);    // 2. turns servo to closed position.
    delay(1000);                              // 3. wait 100 milliseconds
    servo9g.detach();                        // 4. detach the servo
}

void armtrap()
{
    //Indicate trap armed
    piezoSpeaker.playMelody(piezoSpeakerArmedLength, piezoSpeakerArmedMelody, piezoSpeakerArmedNoteDurations);
    delay(500);                        
}

No Candy For YOU!! Arduino Project Code

Credits

Jonathan Tindal

Jonathan Tindal

3 projects • 3 followers
Telecom Software Engineer by day, maker and artist by evening before a reasonable bed time.

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