Final Assembly

After a thorough analysis of the advantages and disadvantages of each feeding mechanism, it was decided to use the endless screw since it allows more precise control of the amount of food that is being served to the pet. The screw is driven by a servomotor that allows 360-degree rotations. Therefore, establishing a relationship between the number of turns and the amount of food served is possible. Establishing this relationship was critical since, based on this relationship, the pets will be fed according to the size and species determined by the user.

Another key feature of the Smart Feeder was the integration of two independent containers. It was determined that there would be two containers in order for the prototype to provide more flexibility to the user. In this way, the user can feed more than one type of pet of the same or different species. It is important to note that each container has an HC-SR04 ultrasonic sensor, which is placed on the top of the container (attached to the lid). These sensors were used to measure the distance to the closest point and make the correlation between distance and level of food in the tank through this value.

The prototype’s design and the mechanisms were based mainly on the flexibility of the system, ergonomics, and the possibility of being printed in 3D. The final design consists of CAD models published under a free license as well as parts designed especially for this prototype.

The render of the final design is seen in the figure below. As can be seen, the prototype has two cylindrical containers on the top, a complete case that has two slots on the front for mounting the Raspberry Pi Camera, and another ultrasonic sensor HC-SR04. Additionally, the outer case has two slots for the feed outlet. On the outside, there are two bowls where the food is served. Finally, the prototype has a base on which the Raspberry Pi 4 and the electronics were mounted.

The pieces that make up this design were printed in 3D to assemble the prototype. The finished and assembled prototype can be seen in the picture below.