ECE 110/120 Honors Lab Section : Automatic Pet Feeder

By: Kartik Mehra (kartikm3, ECE120), Mukhil Umashankar (mu9, ECE110), Aumkar Renavikar (aar8, ECE110)

1) Introduction

Statement of Purpose

Our group’s goal is to build an automatic pet feeder as two of our group members have a pet. Although automatic pet feeders are already available in the market, most of them are quite expensive and rarely come with a highly customizable and functional mobile app. Our goal is to make a pet feeder which is connected via the internet to your phone and allows you to have many customizable features like time of feed,  number of servings, etc. 

Background Research

We have found many such similar projects with different designs using either an arduino or a raspberry pi. With the arduino, we would need a crystal oscillator to measure the time whereas with the raspberry pie, the realm of possibilities is expanded through the functionality offered through an internet connection. We have seen automated mechanisms built into mechanical feeding machines and also into a mechanism which has been built from scratch. We want to use an on-the-shelf mechanical feeder and make it automatic as our focus is more on the circuits and software. There are many different mechanisms to release the food but we are leaning towards helical corkscrew as we think defining quantities using software will be most intuitive using that. A flap was also a possibility but that makes it harder to get precise quantities.

2) Design Details

Diagram / Flow Chart

System Overview

The power supply connects the two main components of the automatic pet feeder: the electric circuitry and the raspberry pi. All of the electric circuitry ensures that the pet feeder works as it is supposed to, allowing the servo motor to work seamlessly such that the food is dispensed at the correct time. The second crucial part that the power supply connects is the Raspberry Pi, which then connects to the internet. The internet connectivity allows the retrieval of real time which can be used to program when the food needs to be dispensed, and also can be used to access the information that the user provides on the mobile application, allowing the user high level of customization for the automatic pet feeder, such as setting a specific time to feed, the amount to feed and other such functionalities.

3) Parts

1. 1 RioRand Spring SM-S4303R Large continuous rotation servo -  https://www.amazon.com/gp/product/B00X7BPI1K | If unavailable on Amazon: https://www.pololu.com/product/1248. The above specific model as it fits with the food dispenser being used

2. 1 ZevrO Honey-Can-Do Dry Food - https://www.amazon.com/gp/product/B00013K8O4/ 

3. 1 Raspberry Pi 3 model B

4. 1 Raspberry Pi power supply

5. 1 16GB microSD card for the Raspberry Pi - https://www.amazon.com/SanDisk-Ultra-MicroSDHC-Memory-Adapter/dp/B073K14CVB/ref=dp_ob_title_ce

6. Breadboard 

7. 3 Male to female jumper cables 

8. Few 1’’ dowels

9. Wood glue

10. 1 2’’ Carriage bolts with nut for stand

11. Wood pieces to support structure where necessary

12. Resistors of varying resistances

13. Wires of varying lengths and colors

Estimated cost- $70

4) Possible Challenges

1. We feel the list of parts necessary for the automatic pet feeder could change over the course as we better understand the project. However, these additions should be very minor and should mostly concern supporting the physical structure.

2. We hope to control the pet feeder through an app and have various features on it that changes the food quantity fed, frequency of feeding etc. For some of us making such an app and establishing the connection to the feeder is something new, so we may find it challenging to implement the features proposed.

3. Specifications and sizes of the parts listed. Our parts for the mechanical part of the lab is based off another individual who had done an automatic pet feeder. We are hoping the sizes of the specific model of the parts he had used ‘fit’. Otherwise we will need to look for an alternative and make changes to the physical design ourselves with our own choice of specific parts and sizes. 

5) References

1. Rob's Raspberry Pi Powered Pet Feeders. (2017, November 27). Retrieved from https://www.robpeck.com/2017/11/robs-raspberry-pi-powered-cat-feeders/

2. Instructables. (2017, October 2). Internet Enabled Raspberry Pi Pet Feeder. Retrieved from https://www.instructables.com/id/Internet-Enabled-Raspberry-Pi-Pet-Feeder/ 

3. StorinoHi, S. (2019, September 16). Automatic Cat Feeder Using the Raspberry Pi. Retrieved from https://storiknow.com/automatic-cat-feeder-using-raspberry-pi/