Robokitty

Robokitty is a DIY cat (or dog, or human) feeder controlled over the web (though not over the public Internet for now). There are two different feeding methods: instant feeding with the click of a button, or scheduled feedings (using a command scheduler like cron).

The idea behind the project came about because over the past few years all of the feeders I've came across have had a level of complication that weren't very user-friendly to new coders, and I wanted to make something that is easy enough for everyone to use.

Let's get started!

Part list

Part Where to Buy / Price

• Particle Photon Kit (comes with breadboard and USB cable, you can get just the board if you have these other items handy)

• Particle.io / $29 / $19 for just the board

• Male to Male jumper wires

• Adafruit / $3.95 to $7.95 depending on length

• 4xAA Battery Pack with ON/OFF Switch

• Adafruit / $2.95

• 4xAA Batteries Buy these wherever. $4 - 8 Continuous Rotation Servo Adafruit / $11.95

• Dry Goods Dispenser Amazon / $20.99

• or Amazon / $16.14

• USB Cube Charger (like for an iPhone) Amazon / $8.29

Additional Needs

• Soldering Iron

• Solder

• Wire Strippers

• Heat Shrink Tube

• Method of attaching servo horn to feeder, I used Loctite plastic bonder which ruled.

How-To

Once you have all of your materials handy, you're ready to start.

Setting up your Particle Photon

A great guide can be found right on the Particle site, but I will walk you through it! I'm going to assume you're doing this from scratch and don't have anything installed on your computer. Make sure you've already set up an account and logged in on the Particle website before starting the tutorial.

First thing you need to do is power up the Photon, plug in the cable and connect it to your computer. Now you need to install Node, for sake of ease, go to the Node.js site and grab the latest version. Once you've gotten Node installed, the next step differs depending on if you're using Mac OS or Windows.

If you are on a Windows machine, please follow the steps on the Particle site called "Installing the Particle Driver" and "Opening the Command Prompt". If you are on a Mac, there are no additional steps to take before our next one. It's time to install the Particle CLI (Command Line Interface)!

Particle CLI

Open up your CLI of choice, and type:

npm install -g particle-cli

This command may require sudo access. Once it is done downloading, type:

particle cloud login

And answer the prompts with the login information you created earlier for the Particle site.

Claiming a Photon

The Particle site has a thorough guide to claiming and setting up a Photon.

Firmware

Now we need to flash the Photon with new Firmware. We're going to be using VoodooSpark.

If you have already claimed your photon correctly, you're going to need your Photon ID. Type the following, and keep track of what the number is because you'll need it shortly.

particle serial identify

The first thing you need after this is grab the latest version of the firmware.

Save that file locally, and navigate to the directory in the command line. Next thing you need to do is flash the firmware, if you are connected to your Photon you should be ready. Type the following:

particle cloud flash PARTICLE_DEVICE_ID voodoospark.cpp

Now you're ready to start working with the code for the feeder.

Feeder Code

Clone this repo into your directory of choice by typing the following:

git clone git@github.com:rachelnicole/robokitty.git

Navigate into the new Robokitty folder, you're going to have to install your dependencies.

npm install

This will pull down all of the dependencies you need. To configure the Photon Device ID & Token, you can either set it when you start the feeder with the following.

PARTICLE_KEY=your_particle_key PHOTON_ID=your_photon_id npm start

Or you can follow through with the rest of this section.

The next step is to update the config.js file with your Photon's Token and Device ID. The Device ID is the same one that you had used in the previous firmware step. Add that in the deviceID object on the line for device, make the device string no longer empty.

To get the access token, navigate to the Particle Build Site.

Click on the settings link on the left, and copy the access token and add it to the appropriate line in your config.js file. It will be the in the token object that asks for device with an empty string. Add it in so the string is no longer empty.

Before we can actually run the code, we need to set up the hardware part.

Hardware & Wiring Info

Detach the Photon from your computer if it's still attached. We'll connect it to an external power supply now. All you need is to plug the Photon cord into an A/C plug with a UDB port, the same kind that you plug your iPhone into to charge.

Next wire up your Photon according to this diagram.

The 4xAA battery pack wires need to be soldered to two of the MtoM wires that plug into the left rails of the breadboard. Cut off an end of each of the wires and solder the battery pack onto it.

Now, you need to connect your servo to the dispenser handle. Do this the best way you see fit. Even duct tape will work, or you can glue your servo horn to the handle (making sure you keep them parallel to each other so it doesn't break). Experiment with it to find the best way. I built a chassis for the servo out of cardboard and duct tape to support the servo while it's turning. You don't have to do the same. Do whatever you'd like! Acrylic, cardboard, or something else I haven't thought of. I also added a chute to the bottom of the feeder dispenser area that I used a cut up plastic bottle for, because the distance between the mouth of the dispenser and the base was too close. Moving it out further in front allows the cats to access it a lot easier.

Once you're all wired up, you're ready to run the code.

If you bought the same servo as me, you may have some tweaking to do which we will talk about in the next step.

How to run

In the command line, navigate into the main robokitty repository folder. Type the following:

npm start

A browser window should now open up at http://localhost:3000. You have two options, a button and a dropdown.

The button is for instantaneous feeding, while the dropdown is for interval feeding. For the alpha release the dropdown is only going to work while the browser is open to that page. I have added some feature requests to implement a better way of storing the session variables so even if you lose connection with your Photon, it will remember.

Push the button!

The servo should turn and stop. If it doesn't stop, you may need to tune your servo. If it has a trim pot, you can just turn until it stops. If it doesn't, you may need to open up the bottom of the servo and turn the little knob until it stops. If you can't figure it out, please feel free to leave a comment here and I'll try and help you out as best as I can. I'm probably just as new to hardware as you are.