Lots of people celebrate Halloween by making pumpkin sculptures most of them only just carve a scary looking face from the pumpkin and place. in this tutorial, I am showing how to give a more awesome effect to your pumpkins. here I added human/obstacle detection, smoke and lights. let’s scare them all

Step 1: Components Needed for Making

  • Arduino *1
  • mist maker using 555( or you can buy)
  • relay module*1
  • IR module*1
  • neopixel led*2
  • 3D printed pumpkin enclosure
  • battery

Step 2: The 555 Mist Maker Circuit

The main component of a mist maker is a piezoelectric disc the working of the piezo is very simple. Every piezo has its own resonance frequency In our case that is 113kz. So if we apply a 113kz signal With suitable voltage piezo disc will start to vibrate with a 113kz frequency. If we place the piezo on top of a water surface the water will also start to vibrate. mist or fog will form due to the high vibration of water+air

component needed for making mist maker

  • Piezoelectric disc
  • NE555
  • 220uH inductor
  • 10nf capacitor
  • 2*100nf capacitors
  • 10ohm resistor
  • 5k variable resistor

you can check the mist maker tutorial from this Instructables

Step 3: Circuit Diagram of Smoking Pumpkin

this is the circuit diagram here I used an IR module to detect the obstacle/motion. I connected 2 neopixel LEDs to Arduino and a relay. then the mist maker power supply I connected via relay.

Step 4: Building the Cicuit

first I connected wires to their module then I connected the ground and VCC of IR module to Neopixel VCC and ground. Next, I connected the common positive to 5v and common ground to the ground of Arduino, I connected IR output to pin 3 of Arduino and neopixel data into pin 6. Finally, I connected the ground and VCC of the relay module to Arduino and relay input to pin 2.Now let’s set up the mist maker I connected the battery through the relay module

Step 5: Arduino Programming of Smoking Pumpkin

the code is very simple first i included the fastled library for controll the neopixel leds and then i defined the led pin, total number of led etc.


#define NUM_LEDS 2

#define DATA_PIN 6

#define CLOCK_PIN 13


in the setup section i defined the pins and leds

void setup()


pinMode (3,INPUT);

pinMode (2,OUTPUT);

FastLED.addLeds(leds, NUM_LEDS);


in the loop section first I read the state of the IR module and stored it in x. then I gave if condition according to it state.

void loop()


int x=digitalRead(3);

if (x==0)



leds[0] = CRGB::Red;;

delay(500); leds[1] = CRGB::Red;;


leds[0] = CRGB::Black;;


leds[1] = CRGB::Black;;








you can download the code from here

Step 6: The Pumpkin Enclosure

you can either use normal pumpkin or you can download the .st file from here and 3D print that. if you are going with the second option then use orange colour filament.

Step 7: Finishing

finally, insert and fix the IR module and neopixel LEDs inside the pumpkin enclosure . after that I placed piezo on the surface of some water and finally I placed the pumpkin on the top of the water. you can refer to the video If you have any doubt.

Step 8: Tutorial Video


About The Author

Muhammad Bilal

I am a highly skilled and motivated individual with a Master's degree in Computer Science. I have extensive experience in technical writing and a deep understanding of SEO practices.

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