This is a automatic dog feeder that is driven by a Arduino Uno. The dispensing mechanism is a 3D printed archimedes screw driven by a continuous servo motor.
The feeder has two feed times programmable to the user, it also has a programmable quantity allowing the user to customise the amount fed to the dog. A override button is also included to allow the user to feed outside of the set times. The hopper to the feeder is designed to hold 3Kg's of dry dog food
Step 1: Materials
1 x 1200mm x 1200mm sheet of MDF
2" PVC Pipe
-1 x T Bend
-1 x 90 degree Bend
-1 x 45 degree Bend
-1 x Length of pipe (desired length)
2 x 600mm x 400mm 3mm acrylic
1 x Arduino Uno
1 x Continuous Servo Motor
1 x Bread board
1 x RTC DS1307 (Real Time Clock)
1 x Rotary Encoder (Potentiometer with push click)
1 x 10k Potentiometer
1 x 3D printed Archimedes' screw (3D CAD File uploaded)
1 x 10k ohm Resistor
2 x 220 ohm Resistor
1 x Push Button
1 x LCD Display (compatible with arduino)
2 x 47µF Capacitors
Step 2: Cutting and Drilling
Cut panels from MDF - 12mm
2 x 130 x 224mm
2 x 280 x 224mm
2 x 280 x 118mm
Cut panels from Acrylic - 6mm, this will be your hopper.
2 x 350 x 250mm
2 x 250 x 150mm
2 x 350 x 150mm
2 x 138 x 130mm (these will angled panels placed inside the acrylic box)
Now you will drill the holes needed in both the MDF and Acrylic boxes.
Mark and cut on your MDF box, 56mm holes on the front and top panel of your MDF box, positioned according to your particular 'PVC T Joint'.
Using PVA glue, glue all sides together to make a smooth rectangle box. Don't glue the back panel.
Mark and cut a 56mm hole in the bottom panel of the acrylic box, aligning it with the one cut on the top panel of your MDF box.
Using Liquid cement, construct the acrylic box. Don't Glue the top panel.
Now using Liquid Cement, glue in the angled panels to your preference.
Step 3: Hopper Base
Using the off cuts from your sheet of MDF, cut...
1 panel, 238 x 138mm to rest at the bottom, inside the acrylic box
4 sloping pieces using your own judgment. These pieces will help direct the food to the hole and into the feeder.
Glue these pieces as seen in the image.
Step 4: Prep, Spray and Glue
Using a Jig saw, you will need to cut three squares from your chosen side of the feeder. These may be positioned according to your preference.
1 x 80mm x 36mm square to house the LCD display
1 x 35mm x 20mm square to house the Rotary Encoder
1 x 5mm x 5mm square to house the Click Button
Now spray or paint your MDF box!
This completes the construction of both boxes, now align the hole in the Acrylic box(hopper) with the one on the top panel of the MDF box and glue.
Step 5: Print Archimedes' Screw
Using a 3D printer, and the file provided, print the Archimedes' screw.
Step 6: The Circuit
Copy the above image and/or Fritzing file to assemble the circuit needed for the feeding mechanism.
The Push element to the Rotary encoder enters and navigates the customisable times and quantities. You will see a blinking tile on the LCD showing where the cursor is.
The Potentiometer element of the Rotary encoder alters the numbers/quantities.
The 10k ohm Potentiometer controls the brightness of the LCD.
The Click switch allows the user to feed at anytime upon click.
Step 8: Final Assembly
Fix the Servo to the base plate of the Archimedes' screw. Insert the screw into the pipe in the box and bix to base of box.
Insert the LCD, Rotary Encoder and Push Button into the appropriate openings of the MDF box
Place cut Pieces of Acrylic appropriately over the face of each component and fix using screws.
Depending on the particular models of these components that you're using, these fixing will have to be modified to their specific design.
Fix rear panel of the MDF box encasing the electronics.
Assemble your tubing made from your PVC pipe and joints. Cut down pipe to dispense from desired height.
AND YOU'RE DONE!!