DIY Cat & Dog Feeder Using Raspberry Pi

Our pets, especially cats and dogs, get hungry very often. You may sometimes feel too lazy to refill their food. This is quite normal. I too often feel lazy to keep refilling my beloved cat Oslo's food bowl :).

That's why I decided to prepare a very useful project both for myself and for you: raspberry pi cat feeder.

If I were to list the features of our amazing robot:

1. Thanks to its automatic timer feature, it automatically refills the food compartment at the intervals you set.
2. The robot detects when the food is finished thanks to HC-SR04 (LDR), and a warning appears on the OLED screen and the robot makes a beep sound.
3. Your pet can develop a placebo effect as it makes a beep sound while dispensing food.

Great features, aren't they? Let's then learn step by step how to make a DIY automatic cat and dog feeder.

Wiring Diagram

Step 1: Let's Print with a 3D Printer

One of the best aspects of this project is the opportunity for 3D printing. This way, you can create your own pet feeder at home for free. 

Don't worry, I have shared the necessary STL files below:

Download 3D STL Files

Let's Load the Codes onto Our Raspberry Pi

You can easily load the codes I will share below from BricksIDE or any application that supports Raspberry Pi. If you don't know how to do it, you can read our article:

How to Use PicoBricks with Micropython?

Here are the codes:

# time_tracking.py

import time
from machine import Pin
from machine import I2C
from picobricks import SSD1306_I2C
from machine import PWM
from math import fabs
import utime

i2c = I2C(0, scl=Pin(5), sda=Pin(4), freq=200000)
oled = SSD1306_I2C(128, 64, i2c, addr=0x3c)
pwm_1 = PWM(Pin(21))
pwm_1.freq(50)
buzzer = PWM(Pin(20))
trigger = Pin(15, Pin.OUT)
echo = Pin(14, Pin.IN)
  
def getDistance():
   trigger.low()
   utime.sleep_us(2)
   trigger.high()
   utime.sleep_us(5)
   trigger.low()
   while echo.value() == 0:
      signaloff = utime.ticks_us()
   while echo.value() == 1:
      signalon = utime.ticks_us()
   timepassed = signalon - signaloff
   distance = (timepassed * 0.0343) / 2
   print("The distance from object is ",distance,"cm")
   return distance

def CalculateAngle(angle):
   angle = fabs((angle * (6000 / 180)) + 2000)
   angle = round(angle)
   return angle

# Configure the hardware timer
timer = machine.Timer()

# Define a global variable to store the elapsed time
elapsed_time = 0
# Function to be called by the timer interrupt
def timer_callback(timer):
    global elapsed_time
    elapsed_time += 1

# Configure the timer to call the callback function every second
timer.init(freq=1, mode=machine.Timer.PERIODIC, callback=timer_callback)

# Main loop
while True:
    pwm_1.duty_u16(CalculateAngle(0))
    # Print the elapsed time every 5 seconds
    oled.text("It'll give food",0,0)
    oled.text("in every",0,10)
    oled.text("12 hours?",0,20)
    oled.show()
    distance = getDistance()

    if distance < (5):
        oled.fill(0)    
        oled.text("FEEDING TIME",10,30)
        oled.show()

    else:
        oled.fill(0)
        oled.text("{}".format("Mama Bitti"), 0, 0)
        oled.show()
        #buzzer.freq(300)
        #buzzer.duty_u16(100)
        time.sleep(0.25)
        
    if elapsed_time % 10 == 0:
        pwm_1.duty_u16(CalculateAngle(30))
        time.sleep((5))
        print(elapsed_time)
        
    time.sleep((1))        
    oled.fill(0)

    # Sleep for a short duration to reduce CPU usage

And... that's it. Now you can fill the food bowl and give your happy cat a belly rub.

If you have any questions, don't hesitate to ask. Take care :)