Cat Sprayanator 9000

Have you every had a cat that wouldn't stop getting on the counter. My cats love to do that when we are not around. This poses a problem, especially around Thanksgiving. On the other hand, it is fun to torment cats. If you have a micro-controller, a servo and a few extra PIR sensors... you could make it motion tracking. Don't get any ideas.

How to:

Things you will need:

Everything you need for this project can be bought at local stores. You can try out Radio Shack, Walmart, ect. Estimated cost is about $30.

• PIR motion sensor with a 3.3 volt or 5 volt output/input
• 2 1.0 uf capacitors
• Solder
• Soldering iron
• Philips screwdriver
• Hot-glue gun
• Small piece of cardboard
• Drinking Straw
• A breadboard and proto-board
• Wire, 22 gauge works best with the breadboard and proto-board
• 5 volt regulator IC (L7805)
• 9 volt battery
• 9 volt battery clip
• Raid Max Bug Barrier with Auto Trigger (I've found these at Walmart, Walgreen's and hardware stores)
• A relay or transistor (If you use a transistor, you may need resistors to pull down the voltage going into the auto-trigger
• A switch
• 220 ohm resistor
• 3.3 volt LED
• Toilet paper tube
• Cardboard

Step by step......

Make a 5 volt regulator. If you have any questions about 5 volt regulators, click to visit this web page.

Image from instructables.com

5 volt regulators are very simple. This one takes 9 volts and brings it down to 5 volts. This is a diagram of one connected to an LED. You can test your 5 volt regulator with an LED or voltmeter.

Test the PIR motion detector by attaching it to an LED like so. The P0 goes to the risitor and LED. The VSS goes to ground and the VDD goes to the 5 volt output of your 5 volt regulator. Click here to see Radio Shack's PIR datasheet.

After the test circuit is built, wave your hand in front of the motion sensor. If everything is working, then the light will turn on when it senses motion. You now have the circuit you need to detect motion and activate the auto-trigger. The next step is to get the auto-trigger ready.

Begin to take the auto-trigger apart. Be sure not to loose screws because they will be re-used later.

Here is the battery case. It sends current to the motor when the blue button is pressed by the trigger. What you want to do is remove the button and solder two wires to the leads. Then, these two wires need to go to a switch of some sort. You can use a MOSFET transistor or relay. Transistors are cheaper and smaller. I would recommend the transistor, but be careful you don't send too many volts to the motor by accident. I used a relay because that is all I had.

You can test the soldering job by putting the batteries in and then completing the circuit. Test this before you put the whole thing back together.

Hot glue a straw like so. Make sure that the seal is airtight. Any leaking water could cause problems.

Stick the wire through the hole that was originally meant for the safety. Re-assemble the spraying nozzle and put the screws back in. If you want to reuse the bottle it came with, you can attach the yellow screw on piece. But, make sure the bottle is washed out well. Whatever bottle you choose, make sure that it doesn't shake while it pumps water. This will cause it to constantly sense motion and it will never stop shooting.

Test the circuit to and make sure everything is working properly.

Solder your circuit onto a proto-board. Attach the motion sensor to the inside of a toilet paper tube. This will make it so that it will only sense motion directly in front of the spay gun. Some motion sensors come with dials to adjust the sensitivity. You can play around with this and the tube to tune it to your needs.

Mount everything using hot glue. Put the battery on the opposite side of the circuit to keep it balanced. Put the tube on top pointing in the direction that it is going to spray.

The last step is to test it. Adjust anything that you need to including the sensitivity of the motion sensor. Then place the device in a spot to spray your cats. This will keep your cats off a certain part of the counter. Although, it will spray a lot of water depending on how often your cat gets on the counter. So, be careful that it does not spray anything that you don't want to get wet.