Training Fish to feed Themselves

We’ve featured quite a few aquarium and fish feeder hacks on our blog. [RoboPandaPDX] thought of taking it up a notch and make an interactive fish feeder. He built a Fish feeder that train’s them to feed themselves.

A copper bar hangs from the middle of a metal cylinder – much like a bell. The end of the bar has a fish lure. When a fish pushes the lure, the copper bar touches the metal cylinder and  closes the circuit. This signal goes to an Arduino. To catch the attention of the fishes and to “teach” them, an RGB LED is used. The fish need to figure out that the feeder will dispense food only when the LED is ON and the Lure is pushed. If the fish figure that out, and push the lure when the LED is on, a servo is activated which pushes the feeder to deliver 1 unit of fish food. While at it, he added a couple of bells and whistles. A buzzer to indicate when the Lure switch is closed and a 2 line LCD shows how many times the switch has been activated and how long the program has been running.

A Sparkfun  open logger stores the hit count and the minutes and seconds of the hit for data analysis later on. The good news is that it seems to be working. The current code activates the feeder for 30 to 60 minutes every day, which is indicated by the LED. At the end of 9 days,  [RoboPandaPDX] found that the goldfish would hit the Lure when the LED turned on, and then turn around to face where the feeder would dispense food in to the tank. His next plan is to put up some obstacles along the path to see if the fish learn some new tricks. His schematic looks a little iffy (the Lure switch is connected to the RST pin of the Arduino), and it seems he cannot remember why he ever did that. He’s happy that it works though, but we’re sure that’s not the right way to wire it up.

[RoboPandaPDX] is looking for suggestions on improving his interactive feeder, so if you have any, do add them in the comments below.

If you need some more fish feeder ideas, check out this and this that we blogged about earlier.

3D Printed Fish Feeder

[Helios Labs] recently published version two of their 3D printed fish feeder. The system is designed to feed their fish twice a day. The design consists of nine separate STL files and can be mounted to a planter hanging above a fish tank in an aquaponics system. It probably wouldn’t take much to modify the design to work with a regular fish tank, though.

The system is very simple. The unit is primarily a box, or hopper, that holds the fish food. Towards the bottom is a 3D printed auger. The auger is super glued to the gear of a servo. The 9g servo is small and comes with internal limiters that only allow it to rotate about 180 degrees. The servo must be opened up and the limiters must be removed in order to enable a full 360 degree rotation. The servo is controlled by an Arduino, which can be mounted directly to the 3D printed case. The auger is designed in such a way as to prevent the fish food from accidentally entering the electronics compartment.

You might think that this project would use a real-time clock chip, or possibly interface with a computer to keep the time. Instead, the code simply feeds the fish one time as soon as it’s plugged in. Then it uses the “delay” function in order to wait a set period of time before feeding the fish a second time. In the example code this is set to 28,800,000 milliseconds, or eight hours. After feeding the fish a second time, the delay function is called again in order to wait until the original starting time.

Microbial Fuel Cell with a Side of Betta Fish

Move over, potato batteries: DIY microbial fuel cells are here to stay! A microbial fuel cell (MFC) is a device that uses bacteria in an anaerobic (oxygen-poor) environment to convert chemical energy into electricity. [drdan152] posted steps on how to make a soil-based MFC  with a neat twist: it’s also a fishbowl for a betta fish.

[drdan152] used soil from the wetlands, referred to as “muck.” This nutrient-rich soil provided a hearty supply of bacteria, especially Geobacter species, known for their uncanny ability to transport electrons outside their cells using bacterial nanowires. The proton exchange membrane (PEM) was made up of salt, water, and agar. After some initial runs, [drdan152] determined that flat char cloth made the best anode, while red copper wire served as the cathode. Assembling the MFC was as simple as surrounding the anode with a thick layer of muck on all sides, adding the PEM on top, followed by water. The cathode was situated halfway out of the water.

After a couple of days, the voltage increased in proportion to the amount of bacteria growing on the anode. The betta fish can happily live in this habitat for a short period of time(it still has to be fed, of course), and the bacteria certainly won’t mind – the fish’s excrement provides an additional food supply. As a bonus, the water is kept clean. However, like any aquarium, the water will need to be changed periodically as carbon dioxide byproduct accumulates from the fish’s respiration and the MFC (high carbon dioxide levels = dead betta fish).

The MFC generates 725 mV. [drdan152] is not satisfied with that number, and is testing out charge pump circuits to generate as much as 3V. We are looking forward to seeing the results. We also wonder if a small aquatic plant could help make it a more self-sustaining environment for the fish. In the meantime, [drdan152] is encouraging others to try larger-scale versions of this MFC. Perhaps MFC-powered carnivorous robots doubling as mobile aquariums are in our near future.

DIY Auto Fish Feeder Feeds Fish Automatically

[Brian] has a fairly large 400 liter aquarium and loves the fish that call it home. Unfortunately, sometimes life gets in the way of keeping those fish fed on a regular basis. There are automatic fish feeders out there on the market and [Brian] gave one a try. Although it worked, it dropped one huge clump of food in at a time (rather than sprinkling it in), the food hopper held a very small amount of food and the unit drained a new set of batteries in less than a week. Fifty euros were spent on purchasing that auto feeder and in the end it wasn’t any more convenient than just feeding the fish.

Faced with a tough decision on whether or not to buy another product he may not be happy with, [Brian] decided to make his own automatic fish feeder system out of parts anyone can find lying around the house. The main housing is a small Tupperware bin, inside of which 3 pieces of plastic were glued together to make a v-shaped hopper. The fish food is loaded into the hopper and as it falls to the bottom it meets a reverse-spinning drill bit that acts like an auger, pushing the food out of the container. The drill bit is powered by a small stepper motor connected to the drill bit by an improvised coupling made from a silicone sealant cap!

The control system is an Arduino and a stepper motor driver chip. Through trial and error [Brian] figured out that 100,000 half steps of the motor dumped a good amount of food into the tank. The drill bit delivery method even sprinkles the food nicely for total fish enjoyment. To keep the food flowing at regular intervals, an AC timer unit controls how often the Arduino is powered on and subsequently feeds the fish.

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The Abovemarine

Over the course of a few weeks, [Adam] trained his betta fish, [Jose], to jump out of the water to snatch food off his finger. An impressive display for a fish, but being able to train his small aquatic friend got [Adam] thinking. What’s stopping [Jose] from interacting his environment even more? The abovemarine was born.

The abovemarine is a robotic platform specifically built for [Jose]’s aquarium. Below, three omni wheels drive the entire aquarium in any direction. A computer running OpenCV, a webcam, and a few motors directs the abovemarine in whatever direction [Jose] wants to go. Yes, it’s a vehicle for a fish, and that’s awesome.

[Adam] put a lot of work into the creation of the abovemarine, and was eventually able to teach [Jose] how to control his new home. In the videos below, you can see [Jose] roaming the studio and rolling towards the prospect of food.

Because [Jose] is a Siamese fighting fish and extremely territorial when he sees other males of his species, this brings up the idea of a version of Battlebots with several abovemarines. They’re in different tanks, so we don’t know what PETA would think of that, but we do expect it to show up in the Hackaday tip line eventually.

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18-Channel PWM Aquarium Lights Provide Habitat-Like Life for Fish

Aquarium with variable LEDs

Whether you want to keep your fish happy or just need a good light show, this aquarium light fits the bill. It is the second iteration, but [William] calls it v1. That’s because v0 — which used a few loops of LED strips — never really met his requirements.

This build uses just six LEDs, each a 30 Watt RGB monster! To source about 350 mA for each, and to control brightness with 18-channels of pulse width modulation, he had to plan very carefully. This meant a proper aluminum project box and a beefy, fan-cooled power supply.

The driver board is his own design, and he etched a huge board to hold all of the components. Everything is driven by an Arduino Mega, which has 16 hardware PWM channels; two short of what he needed. Because of this he had to spend a bit of time figuring out how best to bit-bang the signals. But he’s putting them to good use, with fish-pleasing modes like “sunset” or the “passing rainbow” pattern which is shown in the image above.

If you need something a little less traditional why not house your fish in a computer case, complete with LED marquee for displaying data.

Yo Fish, We Pimped Your Tank

fishie

[Studio Diip] a machine vision company based in The Netherlands has created fish on wheels, a robotic car controlled by a goldfish. The idea of giving fish mobility on land is nothing new, but this definitely is a novel implementation. A Logitech 9X0 series camera captures overhead images of the fish tank. The images are then fed into a BeagleBoard XM, where they are processed. The image is thresholded, then a centroid of the fish-blob is determined. With the current and previous blob locations known, the BeagleBoard can determine the fish’s swim direction. It then and commands the chassis to drive accordingly.

The system appears to work pretty well on the video, however we’re not sure how much of the input is due to the fish swimming, and how much is due to the water sloshing and pushing the fish around. We definitely like the chrome rims and knobby tires on the fishes’ pimped out ride.  This could become a trend. Just make sure no animals or humans are hurt, and send your animal powered hacks to our tip line!

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