Introduction & Showcase Video
Idea
Landscaping
RGB LEDs
Monsters
Rocket
Capacitive Touch Sensors
Code
Result

Published September 15, 2019 © CC BY-NC-SA

Space Monsters - An Interactive Painting

Also tired of hearing "NO!" when you want to touch a painting? Let's make one you CAN touch!

IntermediateFull instructions providedOver 1 day587

Space Monsters - An Interactive Painting

Things used in this project

Hardware components

Raspberry Pi 3 Model B

Adafruit Capacitive Touch Sensor Breakout - MPR121

SG90 Micro-servo motor

Adafruit Flora RGB Neopixel LEDs- Pack of 4

Monster Fabrics

Plenty of googly eyes

Canvas

Paint

Popsicle stick

duct-tape

Glue

Copper Tape

Software apps and online services

Autodesk Tinkercad

Hand tools and fabrication machines

3D Printer (generic)

Scissor, Electrician

Sewing needle

Story

Introduction & Showcase Video

Also tired of hearing “NO!” when you want to touch a painting? Let's make one you CAN touch!

Idea

The idea is to make a painting you can touch using a Raspberry Pi and an Adafruit capacitive touch sensor. When you touch certain parts of the painting, things will light up & move. In this case, the painting is space themed, because space is awesome. Let's do it!

Landscaping

The first step is to get a canvas and start painting! We'll start by painting it all black, it's outer space after all, and then adding a moon-like landscape.

Painting a space landscape

To add some more planets to the imaginary galaxy, I 3D modelled and printed two blobby planets, one in neon green and one in orange.

3D model of a blobby planet

3D printing the previously mentioned planet

RGB LEDs

We'll be using RGB LEDs to add some light to the painting. We still had some Adafruit Sewable Neopixels laying around, so I used those. Make holes in the canvas where you want to place them. To do this, I first used a large needle and then a pencil. Very high tech!

Poking holes in the canvas!

After adding the holes, the painting itself is complete. To make it durable and also stop the holes from fraying and ripping, add some coats of protective varnish. I added two layers of a very glossy varnish, making it feel nice to the touch.

Varnished canvas with holes

Once the placement of the LEDs is set, you can wire the Neopixels by following this guide.

Note that I didn't actually sew them to the canvas, I used some quick and dirty duct-tape. Yes, I know... I'm still figuring out a more permanent solution, I think I'll just superglue them in place.

Neopixel!

To diffuse the light and cover up the holes, I 3D modelled and printed some LED covers in transparent PET, which I then glued to the painting.

LED covers

Monsters

Sadly, I'm not the next Picasso so I won't be attempting a difficult painting. As I would also like the painting to be fun to touch, I decided to cut two space monsters out of fluffy fabrics and added googly eyes. I glued them into place on the previously painted and varnished space landscape. Perfection!

Fabric Monsters

Rocket

No space themed thing is complete without a rocket!

The idea is to add a rocket that moves around the green planet using a servo.

I sketched a rocket on paper, cut the pieces out of felt and sewed it all together by hand. I glued a Popsicle stick to the servo mount and added a bit of Velcro to the rocket and the end of the Popsicle stick. The servo was added to the back of the painting using... you guessed it.. more duct tape!

Rocket science using felt

Capacitive Touch Sensors

Now it's time to add some magic: the capacitive touch sensor!

You set it up by following this tutorial.

After the sensor is ready, you'll need to wire it to the places you want to make interactive. I added copper tape to the back of the painting, in the four spots that you can touch to interact with the painting (monster on the left, the monster on the right, the orange planet and the green planet). Believe it or not, it actually works really well, even through some thicker surfaces! It's really magical!

Adding conductive copper tape

The one thing that wasn't mentioned in the tutorial but is very important, is that you need to re-calibrate the sensor when adding things to it, for instance when you're wiring it to a certain spot using conductive tape. It might seems quite obvious but it wasn't mentioned anywhere and I spent a full day trying to figure this out...

I wired the pins of the capacitive touch sensor to the four copper touchy parts using some alligator clips.

Code

The last part: sprinkling in some code to get the magic working!

The full code is added in the code segment, but I'll roughly outline it here:

If you touch the fluffy blue monster on the left, the LEDs turn light blue for 3 seconds.

If you touch the purple monster on the right, the LEDs turn purple for 3 seconds.

If you touch the orange planet, the LEDs turn orange for 3 seconds.

If you touch the green planet, the LEDs turn green and the servo with the rocket on it moves back and forth.

If you don't touch anything at all, the LEDs are a dark blue.

Result

Tadaaa! A magical interactive painting of two monsters in space!

Magic!

Space Monsters

Code

SpacePainting.py

import board
import busio
import time
import os
import json
import RPi.GPIO as GPIO
from random import randint
import board
import neopixel

# I2C setup
from adafruit_cap1188.i2c import CAP1188_I2C
i2c = busio.I2C(board.SCL, board.SDA)
cap = CAP1188_I2C(i2c)

# Setup servo
servoPIN = 17
GPIO.setmode(GPIO.BCM)
GPIO.setup(servoPIN, GPIO.OUT)

p = GPIO.PWM(servoPIN, 50)  # GPIO 17 for PWM with 50Hz
p.start(2.5)  # Initialization

# On a Raspberry pi, use this instead, not all pins are supported
pixel_pin = board.D12

# The number of NeoPixels
num_pixels = 4

# The order of the pixel colors - RGB or GRB. Some NeoPixels have red and green reversed!
# For RGBW NeoPixels, simply change the ORDER to RGBW or GRBW.
ORDER = neopixel.RGB

pixels = neopixel.NeoPixel(pixel_pin, num_pixels, brightness=0.2, auto_write=False, pixel_order=ORDER)



# Recalibrate the capacitive touch sensors 
for i in range(1, 9):
    cap[i].recalibrate()
    time.sleep(1)
    print(i)



while True:
    pixels.fill((0, 0, 255))
    pixels.show()
   
    p.ChangeDutyCycle(0)
    for i in range(1, 9):
        if cap[i].value:
            print("Pin {} touched!".format(i))

        # Green planet that launches rocket           
        if cap[1].value:
            print('Cap 1 Touched, moving servo')
            ##            os.system('mpg123 /home/pi/Desktop/music/rocket.mp3')
            pixels.fill((255, 0, 0))
            pixels.show()
            p.ChangeDutyCycle(12.5)
            time.sleep(3)
            p.ChangeDutyCycle(2.5)
            time.sleep(3)

        # Hairy monster on the left        
        if cap[3].value:
            print('Cap 3 Touched')
            ## os.system('mpg123 /home/pi/Desktop/music/monster.mp3')
            pixels.fill((66, 239, 245))
            pixels.show()
            time.sleep(3)

        # Blobby monster on the right       
        if cap[5].value:
            print('Cap 5 Touched')
            ##            os.system('mpg123 /home/pi/Desktop/music/robot.mp3')
            pixels.fill((242, 66, 245))
            pixels.show()
            time.sleep(3)

        # Orange planet        
        if cap[8].value:
            print('Cap 8 Touched')
            ##os.system('mpg123 /home/pi/Desktop/music/space.mp3')
            pixels.fill((128,255, 0))
            pixels.show()
            time.sleep(3)

Space Monsters - An Interactive Painting

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

Introduction & Showcase Video

Idea

Landscaping

RGB LEDs

Monsters

Rocket

Capacitive Touch Sensors

Code

Result

Custom parts and enclosures

LED Cover

Planet

Code

SpacePainting.py

Credits

Comments

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Space Monsters - An Interactive Painting

Space Monsters - An Interactive Painting

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

Introduction & Showcase Video

Idea

Landscaping

RGB LEDs

Monsters

Rocket

Capacitive Touch Sensors

Code

Result

Custom parts and enclosures

LED Cover

Planet

Code

SpacePainting.py

Credits

Comments

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