This instructable is designed to not only build from mostly house-hold items a fish feeding flux capacitor in a book that is powered by Arduino, rather it also serves a purpose in showing that anything is possible and that often-times the simplest things can be combined into something beautifully complex.
I have used a variety of my own knowledge, information from online, and some other instructables which I will properly give credit to throughout this instructable.
You can also see this project featured on EternityAthletics.com
DISCLAIMER: Some of the links within this instructable may correspond to affiliate relationships. I will provide alternative locations to purchase, and if you choose to purchase through the links I may receive a small commission however you will not be charged extra for said purchase.
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Step 1: Materials
- (1) Sheet of 8" x 10" acrylic, 0.080" thick (I purchased mine from Lowe's, also available at Home Depot)
- (1) 9V Battery
- (1) Plastic drinking straw (I had some thicker ones, but regular restaurant straws will work)
- (1) Motor (any small one will do, but I had some of these Hubsan replacement motors around)
- (3) Water bottle caps
- (3) 3-4" pieces of yellow 20awg wire
- (3) 1-2" nails
- (1) Book
- (1) Arduino Pro Mini MEGA328P (also available from Fry's Electronics and some local electronic stores)
- (1) Breadboard power supply module compatible with Arduino (you could wire your own, or purchase similar ones from Fry's Electronics)
- (3) 5mm Blue LED bulbs (I used round as it was easy to mount into the water bottle cap, these are also available on eBay, at Radioshack, and at Fry's Electronics)
- (1) 9V Battery Lead with Electrical Wire (Also availabel at Radioshack, Fry's Electronics, and possibly Walmart in some areas)
- (3) Wing nuts (preferably orange or red to more closely match the Flux Capacitor look)
- (1) Resistor, 270 Ohm
- (1) Transistor, PN2222
- (1 - optional) Diode, 1N4001
Step 2: Tools
- Power drill
- Drill bits (sized for the diameters of the LED and motor)
- Hot glue gun
- Soldering Iron and Solder
- Table saw, Band saw, or similar saw to cut the Acrylic Sheets
Step 3: Hollow the Book
For this part I browsed through this instructable:
Here is the process I followed:
- Tape the inside front cover of the book completely so that the wood glue does not adhere to the cover.
- Close the book and spread wood glue all over the sides of the pages.
- Clamp the book shut and use your finger to wipe the glue clean for a more "book-like" appearance of pages as if there weren't glue there (it will look better when it dries)
- When the glue has completely dried (I let it sit in direct sunlight for 2-3 hours), open the front cover. You may need to use a box cutter or other fine blade to release the taped area from the wood glue.
- Mark the area you want to clear out with a pencil, and then start using the box cutter to cut out 5-10 pages at a time. This was extremely time consuming and it requires a lot of patience. I'll be honest in saying that about 20-30 minutes in I started switching between a dremel, a drill, an angle grinder, and the box cutter in order to get the rest of the pages hollowed out.
- Once the book is hollowed remove all tape and excess materials, use sandpaper to clean the cut areas and form more perfectly the inside of the box.
Step 4: Create the Feeder Tank / Electronics Holding Panel
This step will have to very calculated as the workable volume inside your book may be different than the volume I had in mine. The concept as seen in the picture is that the tank will fit to the right of the electronics sitting on a panel that covers the entire back area of the book, which allows the electronics to then sit on that panel to the left of the tank. The tank has an angled section so that the food or other contents will be allowed to drain properly towards the exit.
- Determine the height and width of the area hollowed in your book. Cut 1 acrylic piece to those dimensions.
- Measure the thickness of the book when closed and subtract the thickness of the covers. This will give you the inside thickness that your tank will be able to consume.
- Using the measurements from step 2 you can then cut the sides of your tank from the remaining acrylic sheet.
- Now you'll need to cut the front side of your tank out. The top and left side of these will be the same as your tank size, however the right and bottom will change as there is a slant. See image for more details
- Assemble the tank together using hot glue. Either leave a space open at the bottom or drill a hole once the tank is assembled.
- Once you have this completely assembled, place the tank inside the book and drill a hole directly under where to tank feeds out of. It might seem weird because you are drilling against the side of the pages but if you clamp the book tight the drill will go through fine without ruining the pages.
Step 5: Mount Motor
As seen in the image above my motor is mounted with a small piece of scrap wood I found lying around. I drilled a hole at the edge of this wood the diameter of the motor so it would slide right through and sit flush against the acrylic when mounted.
Using the motor I linked, this will allow you just enough room to mount it touching the acrylic while still having space for a rotating disc to control passage of food.
Take the measurement of the thickness of your tank (maximum allowable thickness inside of the book) and cut a square of acrylic that size. Then taking a dremel or some sandpaper you'll need to round out this square so that it creates a circular acrylic piece.
Drill a hole the size of the motor shaft into the center of this acrylic, and drill a larger hole (mine was around 3/8" diameter between that hole and the outer edge.
Push the motor shaft through the center hole and secure with hot glue if needed. Then use hot glue to mount the motor and it's wooden mount to the side of the tank as seen in the image. Make sure that when you do this the disc can freely rotate even when the book is closed (you'll have to sort of eyeball this).
NOTE: At this point you will want to play with the tank/motor fit-up because the disc must rotate to the point where it allows food to pass through the drilled holed yet not allow it to pass through the sides. The feeder will still function if it does, however it will be messy and it's a better design to have the food pass only through the desired hole.
Step 6: Electronics
See the attached schematic image for reference to the wiring of the electronics. I apologize for the messy schematic, but I am doing an overhaul on my main computer at the time and do not have access to my schematic software.
- Connect the arduino to the LEDs in parallel as shown in the schematic.
- Connect the motor using the transistor and resistor shown above. You can use the diode, but I opted not to because I'm using the last one I have in another project. The motor still worked fine.
- Connect the power supply module to the arduino
- Finally add the 9V adapter to the power supply adapter board.
- Plug in the 9V and you are almost ready to go.
Step 7: Design the Flux Capacitor
To make this part I wanted to go for the most cost effective option as possible and resorted to using things I could find around the house. Honestly I'm quite pleased with the way that it turned out, especially for using such rudimentary items.
- Drill 3 holes into the book cover where your LEDs will be pushed through completely.
- Drill 3 holes the exact size of the LED diameter in the side of each of the 3 bottle caps.
- Push the LEDs through the bottle cap holes from the inside to the outside.
- Use hot glue to glue the three bottle caps down over the 3 holes in the book cover with the LEDs all facing inward.
- Cut 3 lengths of your straw to 1" and 3 pieces to 1/2" length.
- Use the 1" pieces to glue onto the book cover making 'tunnels' for the LEDs to shine through.
- Glue the 1/2 straw pieces vertically onto each bottle cap.
- Hot glue a 1" nail to each of the vertical straw pieces so they face inward as seen in the picture. If you get longer nails you can have them point closer together to resemble more of the look of the real flux capacitor.
- Hot glue one strand of yellow wire to the top of each wing nut (these won't be live wires)
- Hot glue each wing nut to the top of a vertical piece of straw. The top to should face down and the bottom one should face to the right.
- Then hot glue the free-floating piece of wires down to the book cover as shown in the image
Step 8: Programming the Arduino
This was actually the easiest part of the whole instructable.
Use the code seen in the image to control the frequency of motor turns and the LEDs as well. In this code I have the LEDs constantly on, but you can have them go on or off while the food is being delivered or even have them on for a certain time after the food has been delivered.
The shown code has the motor run every 60 seconds for a period of one second. This is obviously too much food for a fish, but I did this for testing purposes. If you want to feed your fish twice a day then you should change the number "60000" to "43200000" which is the number of milliseconds in 1/2 a day.
If you'd like to learn more about programming Arduino there are plenty of instructables on this site, and also a vast library at the Arduino tutorials page here: https://www.arduino.cc/en/Tutorial/HomePage
I used this USB to TTL Serial Converter Adapter to program my Arduino via USB.
Step 9: Enjoy!
Now that you've got everything together you can fill the plastic tank from the top and turn your device on so that your fish will be fed every so often automatically while your fish tank and/or book shelf are decorated with a new Flux Capacitor book.
Please leave comments below on things you liked and suggestions you have for improvement. I accept constructive criticism, however I ask that you be respectful about it.
Also please vote for this instructable as I have combined ideas for 5 of the current contests and have displayed a great creativity and innovation in doing so. These are the 5 contests this instructable is categorized for:
- Tech Contest
- Animal Innovations
- Make it Glow
- Book It!
I was going to do Back to the Future but I didn't make the deadline, which is unfortunate because this whole design is based on the flux capacitor! Please vote!
Participated in the
Animal Innovations Contest
Participated in the
Make It Glow! Contest
Participated in the
Book It! Contest