Introduction: VNC Connected Scratch Visual Interface Raspberry PI Powered IOT Pet Feeder

About: I'm a tool maker that likes to tinker.

My son and I decided to make this project because we love our dog, our raspberry pi, our scroll saw, and coding with scratch. I have been doing scroll saw projects for a long time and we have been designing games in scratch for almost a year. It was a lot of fun to bring these two things together and see them do real work.

Step 1: Supplies Software and Tools



  • win32 disk image win 32
  • Real vnc app for your phone vnc
  • noobs for raspberry pi website noobs
  • The scratch program that we wrote scratch for dog or a cat


  • drill press
  • scroll saw
  • table saw
  • computer (with the ability to write on a micro SD card)
  • UV glue amazon
  • cordless drill
  • drills and bits
  • usb mouse
  • usb keyboard
  • staple gun

Step 2: Getting You Raspberry Pi Set Up

  • Download both the win32 and the noobs"NEW OUT OF BOX SOFTWARE" all you have to do is write the image on your SD card
  • Insert Micro SD into the PI.
  • Insert the USB Mouse and the USB Keyboard
  • Now your ready to connect your PI to the internet you have 2 options
    • Directly connect to your router with your ethernet cable
    • Select your WiFi and put in your WiFi password
  • Select Raspbian OS and download it to your pi.
  • Download our scratch dog or cat or you can even make your own for whatever kind of pet you have. I included pictures of all the scripts and costumes that make it work.
  • Hook up your gpio with female to female wires using pin2 (5v) pin 3 (gpio2) pin 6 (ground) pin 16 (gpio23) pin 22 (gpio25) pin 39 (ground).

Step 3: Woodworking

Time to start up the table saw and cut out your pieces.


  • one piece 2'x10"
  • four pieces 8 1/2"x5"
  • one piece 17 3/8"x5"

3/8 plywood

  • three pieces 2"x5"
  • eight pieces 3/8"x5"
  • two pieces 7/8"x7/8"
  • three pieces 1 1/2"x5"
  • one piece 1 1/2"x1 1/2"
  • two pieces 5 1/2"x5 1/2"
  • two pieces 3"x3"
  • two pieces 3/8"x1/2"


  • one piece 2'x10"

1/4 oak dowel

  • one 5 3/4"
  • one 1 3/4"
  • two 2"

Now head to the drill press

  • Drill the center in all the gears use a H drill witch is .2660. That will let your 1/4" dowel spin smooth and was right about the shaft on our motor.
  • Drill the starter hole for your food to flow and for your vibrator motor.
  • Drill 1/4" hole in the center
  • Two of the 2"x5"
  • Both 3/8x1/2"oth 7/8"x7/8".
  • I also drilled 1/4" hole to mount my water container on two dowel rod but I could not find a link to order one like the one we had so yours might be different. Drill the mount for the motor we just used the motor as a guide.
  • Glue the gear patterns to our 5 1/2" and our 3" squares. We got our patterns here.
  • I used 15mm tooth spacing and a contact angle of 20 degrees
  • Both Gear Ones (5 1/2") have 18 teeth
  • Both Gear Twos (3") have 9 teeth
  • Now blow both Gear Ones up so it was just under 5"
  • Now blow both Gear Twos to 2 1/2".

Next use your scroll saw

  • Cut the gears and the holes for the food to flow through. These pieces are made out of 3/8" plywood both the 5 1/2" and 3" squares.
  • The holes we cut out of the gears and the bottom of the shoot where 1 3/8" x 1 3/8" but the bottom was only 5/8" wide in the center and then that goes up 1/4" refer to the picture above. This will prevent food from coming out when it is closed.
  • Cut out the hole for the vibrator motor in the 1 1/2" square and then drill a 1/4" hole in each side for the dowel rods.
  • Out of 1/4" plywood cut the two trapezoids pictured above 3"x4"x1".
  • Put a small notch (like the picture above) in the 17 3/8"x5" piece. This will be the door, the notch is to run your wires through.
  • We also cut out what was like a key-way in our small gears so our motor would fit nice and tight.

Step 4: Assemble and Wiring

Time to assemble your pile of wood and make it a working IOT!

To start lay it all out and figure out what goes where refer to the picture above for guidance.

  • Stable one 3/8" x 5" to the end of each 8 1/2" x 5" piece.
  • Now on the other side stable one 3/8" x 5 3/8" away from the other end of the 8 1/2" pieces.
  • Next take the two 2" x 5"parts that make up the bottom of the shoot and drilled a H hole in the side where the food will sit. The piece for the left chute got a hole in the right and the piece for the right chute will get a hole in the left.
  • Drill both pieces in the center of the hole you cut out earlier with the scroll saw.
  • Now that the holes are drilled and you know which piece goes where sand the top of both pieces so the food would have nowhere to sit and settle.
  • Drill the pilot holes on the large 1/4" piece (the red X's in the picture above that is not to scale).
  • Drill the holes in all the 5" pieces that hold it all together. To do so line up each part were it will be on the large 1/4" piece drilled one hole put a screw in it.
  • Then if the part required two screws line it up and drill the second. When driving the screws have your clutch set on its lowest setting so the plywood does not split.
  • Take out the two 2"x5" pieces that the motors mount to to mount the motors.
  • Run the wires for the motor on the right behind where the trapezoid will end up covering on the chute.To do so drill small holes about an inch above the bottom and as close to the back as you can of the two 8 1/2"x5" pieces that make up the left chute.
  • Run the two wires through the hole.
  • Then use wood glue and glue the two small gears to the motors making sure they spin even and true.
  • Put your door on the top with your small hinges.
  • Now that our main part is all together lay out your wires to where they need to be.
  • Solder them in place.
  • Run the wires to the relay they went to and hooked them up like shown above.
  • Hook up the pi like shown in the same picture using the female to female wires we attached to the pi early.
  • Use a C drill bit hole in your water container and counter sink it a little bit with your H drill bit.
  • Thread in your 1/4" push tube quick connect to a 1/4" thread.
  • Next use your uv light glue and seal up around the connections.
  • Sand one end of both the 1 3/4" and the 5 3/4"dowels so they will not get in the way of the food but will still keep the food from settling by vibrating when the gears open up the chute.
  • Put the 5 3/4" long dowel in the chute on the right after putting the 3/8"x1/2"piece on the end so that the wide part is up and down.
  • Sand the 1 1/2" squares so it will not rub on the gear as it spin and glue with wood glue so the motor is secure .
  • Put the other 1/2" x 3/8"on the end of the 1 3/4" dowel and put it in the hole on left chute and put the vibrator motor mount in between.
  • Slide both 3/8" x 1/2" pieces out so their is just a little bit of wiggle room for the whole vibrator assembly.
  • Sand the top of the large gears so the food will not jam and flow smoothly like the picture above.
  • Put your 2" dowels in the holes on the bottom of the shoot that the large gear will ride on.
  • Carefully put on the gears and then the 7/8" square loosely. Line them up so when it is opens the edges won't get in the way of the food.
  • Spin the gears so both chutes are closed.
  • With wood glue glue in the trapezoid like in the picture above.
  • Use epoxy on the front edge of all the parts and carefully lay down your Plexiglas and set weight on it.

Step 5: Get It Connected

  • Download the app Real VNC on your phone.
  • Find your IP address on your pi. To do this just hover your mouse over your wifi signal in the top right corner. Here is a link to tell you all about VNC.
  • Then with you pi plugged in, open up the app on your phone enter your ip address.
  • The default username for your pi is pi.
  • default password is raspberry.
  • Now if your phone and your pi are on the same network it will connect. If you plan on using your pet feeder from out of the house you will need to do some research on port forwarding. All routers are different so you will have to look up how to do it with yours.
  • I hope you enjoy building and using your pet feeder as much as my son and I have.I hope your pet enjoys it as much as our dog has.
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