This repo contains code supporting home projects that I worked on in my free time over the years.
The purpose of this project was to find a way to feed my dog on a regular cadence, as well as verify that she had been fed. This involved the use of a Raspberry Pi, a Servo Motor, a camera, and some creative assembly of hobby wood, PVC pipe, and a breakfast cereal dispenser.
The servo motor was attached to the rotating part of the cereal dispenser in the place of the handle that would be normally used by a human to manually dispense food. When my program ran, it would cause the servo to rotate, which would cause the dispenser to rotate, thus dispensing food for the dog. The food would then travel down a PVC pipe and into the dog's bowl for consumption.
The code that handled the servo operation was invoked by a cron job on the Rasbperry Pi, which was scheduled 4x a day, so that my dog would be fed equal servings at each meal.
The first iteration of the dog feeder can be seen in action here. Below are two still photos of all the components, and the assembled final version.
As you can see, getting the food into my dog's bowl was a challenge, since I had to use a slow feeding bowl for my dog. Sometimes the food would hit the ridges in her bowl as it tumbled out of the PVC pipe, causing it to bounce out of her crate, or get buried under her crate liner. In addition, there was the possibility of power outages and other issues, which would have impacted my dog's feeding, that I was unable to know about without SSH-ing to the Raspberry Pi and looking at the logs. So, in addition to making modifications to the PVC to increase accuracy of the delivery of the payload, I also added on a process that would take a picture of the food in the bowl immediately after it was delivered, and then email that picture to me, so I could know how well she was fed (or not fed).
The code for this project can be located in the dog-feeder directory.
crontab.txt shows the relevant invocation parameters, as well as starting the necessary daemons to ensure proper operation of the dog feeder from the Rasbperry Pi. As you can see in crontab.txt, the process was invoked by a shell script feedDog.sh. This shell script then invokes the feed-dog.py script, which handles all the logic around operating the servo, taking a photo after the food has been dispensed, and emailing the result to me.
The dog-feeder/test-scripts directory contains "scratch code" that was used to test various options for connecting to the servo, or the camera, etc. This represents iterative testing that ultimately resulted in the final product described above.
Supplies:
- D645MW Digital Super Torque servo from HiTec
- TIP120 transistor
- 10,000 Ohm resistor
- USB Micro power adapter (5V) for a breadboard
- Y-Power Adapter (to power the Raspberry Pi and the Servo separately from the same outlet)
- small breadboard
