Motion Sensor Cat Toy (endless Fun... Literally)





Introduction: Motion Sensor Cat Toy (endless Fun... Literally)

The Motion Sensor Cat Toy uses parts from an old VHS player and other odds and ends to make a cat toy that never stops as long as your cat wants to play! It also starts moving as soon as your cat in near. Big fun for your cat and big fun for you!

Step 1: What You Need

$0.00 Recycle fake fur, wood, integrated circuit board, old tripod, old power brick ,
old leg weights
$0.00 Voltage meter, microcontroller chip, and microcontroller board (my brother's stuff)
$5.99 Motor, capacitor, and wires from an old VHS player bought at Goodwill
$0.00 Motion sensor which requires 3.3-5 volts
(in our electrical stuff box at home; these go for about $8)
$0.00 Solder and soldering iron with fine tip (Dad's; always us goggles)

Step 2: What Each Part Does

" Motion sensor: Detects motion from 20 feet away. When motion is sensed, a single bit output (electrical current) is created. This goes to the microcontroller chip.

" Microcontroller chip: When 5 volt message comes from the motion sensor, the microcontroller says turn on the motor for 5 seconds. My brother helped me with the code and we used his board to put the code on the microcontroller chip.

" Capacitor: This is between power and ground to smooth power to the microcontroller. The capacitor should be as close to the chip as possible.

" ET Tiny 25 chip: The chip holds the code. The code is the brains operating the motion sensor and motor based on electrical impulse.

" Voltage meter: The meter is used to measure how much DC voltage all the parts (motion sensor, motor, and resistor) take. If the voltage isn't correct, things burn up.

" Power brick: The power brick plugs into the wall and sends electricity to the unit (+ and  charge).

" Solder: The solder is fusible metal which connects wires and keeps the current flowing. I used a soldering iron to melt the solder on the VHS board to remove the capacitor. I used solder to attach the wire needed to make the circuit. Always us goggles.

Step 3: Steps to Make This Invention (1 Through 11)

1. Draw the design.
2. Check the voltage of the motion sensor, the microcontroller, and the motor.
3. Solder the microcontroller and solder it in place. (Use goggles when soldering.)
4. Solder the motion sensor output pin to the microcontroller.
5. Solder the microcontroller to the motor.
6. Create pseudo code, write the C code, then load the code on the microcontroller.
7. Solder the power bricks + and - ends to bring electrical power to the motor, motion
sensor, and microcontroller.
8. Build the tripod and wood structure for the moving parts.
9. Mount the parts.
10. Add a box around the motion sensor so it doesn't sense everything in a 20 foot radius.
Or, place the unit in a spot where people don't pass it a lot.
11. Plug in and call... Here kitty, kitty kitty! When the cat goes under the motion sensor, the
kitty toy spins.

Step 4: Step 6 More Info on the Code

Here is the pseudo code and commented C code:

Microcontroller pseudo code

Delay 42 seconds in the beginning (7, 6 second delays)
Port 4 (motor) is the output
Port 3 is the input (motion sensor)
If the motion sensor = 5 V, spin the motor for 12 seconds
Then turn it off

The C code

#include <avr\io.h> // include input and output instructions
#define F_CPU 1000000UL // processor speed is 1 MHz
#include <util\delay.h> // include delay function

int main(void)

_delay_ms(6000); // delay 6 seconds
_delay_ms(6000); // delay 6 seconds
_delay_ms(6000); // delay 6 seconds
_delay_ms(6000); // delay 6 seconds
_delay_ms(6000); // delay 6 seconds
_delay_ms(6000); // delay 6 seconds
_delay_ms(6000); // delay 6 seconds

DDRB |= (1 << 4); // define PORTB 4 as an output, rest inputs

if (PINB & 0x08) // if motion is sensed on PORTB3
PORTB |= (1<<4); // turn motor on
_delay_ms(6000); // delay 6 seconds
_delay_ms(6000); // delay 6 seconds
PORTB = 0x00; // turn motor off

Step 5: Step 8 More Info on the Structure

I used an old tripod for the base, but you could use anything that would hold the parts. I later added Mom's leg weights since our cats could pull over the tripod.

You just have to play around with this, so it is a good idea to keep the arms and height of the invention adjustable.

In the picture, the fur on a string is on one arm of the unit and the motion sensor is on the other.

When the cat goes by, the motion sensor starts moving the toy. While the cat plays, the motion sensor keeps sensing the cat to move the toy. When the cat leaves, the motion sensor stops moving the toy.

After I mounted the parts, I played around with a box around the motion sensor and moved the motion sensor arm around to see where it worked the best to allow the cat to keep the motion sensor working while the cat was still playing.

My motion sensor covers a pretty large radius but yours may be smaller.

Step 6: Moonlight Having Fun!

Here is a picture of one of my cats in action. It is lots of fun to watch them across the room playing with their new toy!
This would be a great toy for someone w
ho is elderly and likes to watch their cat play but can't get around so well.

Step 7: See the Cat Sin Action!

Click a link to see how much fun the cats have!

This link shows how the motion sensor slows and starts the play toy. This is the latest video with the tripod weighted.

This link shows both cats in the action!



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    Please be positive and constructive.




    Great job! And extra points for doing it with your son!


    You teased us with a promise of

    step 7See the cat sin action!

    ... but there was no dirty cat sinning action in the video at all!

    Guess I'm going to have to go to for my kicks...

    1 reply

    Or, if you have an old VHS player in your basement collecting dust (like me), $0.00!

    i just take a string, attach a toy and then attach that to my ceiling fan...:D


    Thats Really cool!

    my cat has gotten caught in these spinning things BE CAREFUL FOR YOUR CATS SAFTEY

    1 reply

    I was going to say keep the string long enough if the cat gets ties up in it he will still land on the ground and be stuck in the air. Cats are 10x quicker than humans so they can get stuck in a rope that is twisting.

    Steven scrabble help fun

    A simpification suggestion for others not wishing to purchase or program a microcontroller. Replace its function with a monostable multivibrator. See Monostable Multivibrator. At its simplest, it is a handful of resistors, a cap, and a pair of transistors, although you will likely want to add a beefy one as a buffer to drive the motor.

    Just a thought. Instead of having the toy spin at a constant speed, which I think is a bit to fast for a cat toy, you should use a stepper motor, say, off of an old floppy drive. That way you could send random pulses to the motor which would add to the randomness while making it a lot safer.

    What a cool project! Nicely done. Mini-Instructable: In the past I have made a much lower tech, quick toy for my cat that is still a riot to watch. Take a regular 1/4" wide rubber band and tie a 8-9' piece of string to it. Stretch the rubber band around a ceiling fan blade (near the tip of the blade). Then cut the string off maybe 4-6" past (longer) where it hits the floor. Tie a second rubber band (or 2) to the end of the string so that when the fan is running at the lowest speed the dragging rubber bands grab the floor a little and hops around the circle as the string pulls it along. Play with string length so it doesn't stay still long enough for the cat to get a solid grab on it. Use a thin, light string (not yarn) so the dragging rubber band(s) catch the cats attention, not the string. The cat will run circles till she is exhausted. Then she will rest and do it again. Really fun to watch. !! CAUTION: Watch out for your cat's safety! Don't run the fan at high speed! Don't leave the rubber band/string on the fan blade when you are not there to watch the cat. My cat has never gotten tangled up in the string, but I imagine it is possible. Great job on the project and the Ible Kateham!

    D'oh, someone beat me to this idea, I've been planning something like this in the back of my head for a long time. The motion sensor part is the crucial piece that has been missing from all motorized cat toys in the stores. My cat won't stay interested in a mechanical cat toy usually because the motor is too loud or the motion is too predictable. She figures out right away that it's a repetitive motion and gets bored quickly. Also, it has to be super dangly with chaotic movement. Nice job.

    2 replies

    The cool thing about using a microchip is that you can build in as much repetitive motion or randomness you want. I could even get really crazy and let the cat have it after a number of seconds or minutes. That could be random too, like those crain machines that only grip enought to give you a toy after a certain numbe of tries. Humm... someone should market one of these.

    We have one of those that has the mirror in it and reflects the laser. The cat likes it for a while - more if it gets in her cube or box. But you're right - she wants it (the light) back in it's own house before long....

    If there's a rubber band in the string holding the lure, it will jump away when she lets go.

    1 reply

    Good idea. That would make the toy a bit more random.

    Please embed the videos in the Instructable. Oh, and your cat seems to be having lots of fun. Maybe if the motor moved more random (see Twitchy, Your E-waste Friend). That would get the cat's attention, that and a laser pointer. Attach the laser pointer at an angle to the motor, then let the cat-fun begin!

    3 replies

    Cool! I'll look at that. Randomness makes for more code. We've messed at home already and found a way to slow and speed the motor. I don't think a project like this is ever really done. There are so many other ideas. On the laser... I'm always afraid with my laser the cat will look in the laser and I will hurt his eyes. At least I've been told not to point the laser at the cat. They are laser lovers, though.

    laser pointers are about Milliwatt and the more powerful ones are 5milliwatt and it takes a mere milliwatt or so laser to blind a human,and thats temporary the reason people say they're blind when a 1 milliwatt laser gets in they're eyes is because your eye will try to adjust to the high amount of light then when you take it off it takes your eye a minute or so to adjust the darkness