Laser cat toy that randomly moves a laser pointer on the ground.
Randomly moves the laser left and right in a 140 degree window.
Randomly moves the laser up and down in a 55 degree window.
Holds the laser in place for a random amount of time between 1 and 3 seconds.
Will randomly “shake” the laser 1 out of every 4 movements, with a “shake” between 3 and 12 shifts back and forth.

Building instructions:

Necessary Materials:
Arduino nano: Link via Amazon
Laser Transmitter: Link via Amazon
MG90S Micro Servo: Link via Amazon
Micro or Mini USB Cable (depending on if you use the adapter below): Micro or Mini
USB plug: Link via Amazon
Zip Ties: Link via Amazon


Additional Materials that are helpful (but can be made without):
USB mini to micro adapter: Link via Amazon
Lever Nuts Connector: Link via Amazon
Junction Box (4.53×3.54X2.1): Link via Amazon
3M Mounting Tape: Link via Amazon
Arduino Screw Terminal Adaptor: Link via Amazon
Jumper Wires: Link via Amazon
Plastic Sheet: Link via Amazon

Optional and Helpful Tools:
Soldering Iron Kit: Link via Amazon
Hot Melt Glue Gun: Link via Amazon

Photos and directions:

1. Cut a small piece of connector material (such as the sheet plastic from above materials, or wood, or any waste plastic will work as well).
2. Dimensions for this should be about 2.5″ length by 1″ width, with a thickness of at least 1/8″.
3. Screw the fist servo (x/y servo connected to pin2) to one side of the piece using the screws supplied with the servos
4. Drill or melt two holes into the plastic to mount the second servo with a zip tie.
5. Attach the second servo to the plastic piece with a zip tie so it looks like this:

6. Drill/Cut/ or melt a box hole into the top of your box to fit the first servo like so:

7. Drill/Cut/Melt a hole in the side if you are using the micro to mini usb converter dongle and connect to the arduino. If not just make a hole for your usb cable to mount to the Arduino.

8. Use double sided tape to mount the arduino to the bottom of the box.

9. Drill/Melt/Cut a hole in the top for passthrough of wires into the box

10. Mount the Laser to the second servo arm with a screw and a zip tie

11. Wire the system according the the diagram below:

12. Push the first servo into the hold in the box and mount with glue or screws.

13. Screw the top of the box down.

14. Finish the system with double sided tape,zip ties and hot melt glue

15. Connect the system up to your computer and open the arduino software

16. Upload the code below to the arduino:

CODE:

//—-Code Begin—

#include <Servo.h>

Servo s1;
Servo s2;

int rn1 =110; //random number 1 for x/y movement, set to 90 intitially
int rn2=50; //random number 2 for z movement, set to 50 initially
int rnt=5000; // random time number set to 1000 initially
int rn3=3; // random number for shake
int rn4=0; // random number for count
int rn5=0; // random number to determin if there is a shake or not

int shake1=10; // change in degrees for shake left right
int maxl=35; // max left movement in degrees
int maxr=175; //make right movement in degrees
int maxd=20; // max down movment in degrees
int maxu=75; // max up movement in degrees
int minshake=3; // Minimum shake in number of shakes
int maxshake=12; //maximum shake in number of shakes
int randshake=5; //max number for determining if there is a shake or not, 5 is one in 4 movements, 10 is one in 9, 2 is one in 2
int mindelay=1000; // minimum delay between movements in ms
int maxdelay =3000; //maximum delay between movements in ms
int shakedelay=50; // delay between x/y movements in shake

void setup() {
// put your setup code here, to run once:

s1.attach (2); // attach pin number to servo 1
s1.write (rn1); // write angle to servo 1
s2.attach (3); // attach pin number to servo2
s2.write (rn2); // write angle to servo 2
delay (rnt); // delay

}

void loop() {
// put your main code here, to run repeatedly:

// get random numbers
rn1= random (maxl,maxr);
rn2= random (maxd,maxu);
rn3= random (minshake,maxshake);
rn4=0;
rn5=random (0,randshake);

//rn1= 90;
//rn2= 90;

rnt= random (mindelay, maxdelay);

s1.write (rn1); //write angle to servo1
s2.write (rn2); //write angle to servo2

if (rn5 == 0) // Check to see if there will be a shake
{
while (rn4 < rn3) //shake while loop
{
s1.write (rn1+shake1);
delay (shakedelay);
s1.write (rn1-shake1);
delay (shakedelay);
rn4=rn4+1;
}
}

delay (rnt); //delay random value

}

// CODE END

Testing:

Plug in the system and make sure it works. You may have to adjust the mounting brackets to make sure the servo is moving where you want it.