
Build your own hackable automated cat feeder for $20 - pweissbrod
https://nachonachoman.svbtle.com/how-to-keep-hungry-tigers-busy-in-the-early-morning
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StavrosK
Friends don't let friends use Arduinos. Please use a Wemos D1 Mini, which
costs $3, has WiFi, runs your Arduino code almost unmodified, and is amazing.

~~~
solidr53
Please recommend the real product (ESP8266) so the guy can choose a dev board,
they are plenty, all with different options.

And for those who dont know ESP32 came out erlier this year and has much
better specs, power consumption, Bluetooth, etc. You'll want that.

~~~
StavrosK
I don't think someone who's using an Arduino will want to go to the bare MCU
directly, and WeMos is the best breakout, so why recommend anything else?

~~~
mplewis
NodeMCU is a contender for best ESP breakout too. It's good to know
alternatives.

~~~
StavrosK
What do you like about it? I have a few, but I don't like how many
redundant/unusable pins it has and how big it is.

I generally find it better to recommend one thing to new people than to
inundate them with options that they can't differentiate between and that,
ultimately, won't matter to them. If you don't know what you want to get, what
service am I doing you by showing you many different options that are more or
less the same, and which you don't know enough to choose between?

~~~
solidr53
Here is a nice article about dev board comparisons.

[http://frightanic.com/iot/comparison-of-esp8266-nodemcu-
deve...](http://frightanic.com/iot/comparison-of-esp8266-nodemcu-development-
boards/)

wemos has a smaller form factor, but lacks breakout, has the ch34 and is
headless so maybe not suitable for beginners like i think of the nodemcu.

edit: also I'd like to add that the nodemcu and sparkfun thing already have a
esp32 upgrade available where the wemos has not.

But hey, just my opinion.

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anotherevan
Reminds me of this recent HN post on cat-proofing a cat feeding machine:
[https://news.ycombinator.com/item?id=13230904](https://news.ycombinator.com/item?id=13230904)
[http://quinndunki.com/blondihacks/?p=3023](http://quinndunki.com/blondihacks/?p=3023)

And the older one on making Monkey the cat hunt for his dinner:
[https://news.ycombinator.com/item?id=10021268](https://news.ycombinator.com/item?id=10021268)
[http://benjaminmillam.com/cat-geek/monkey-the-cat-hunts-
for-...](http://benjaminmillam.com/cat-geek/monkey-the-cat-hunts-for-dinner/)

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mbernstein
From what I've read / discussed with animal nutritionists, you want to feed
your cats pure protein wet food. They get more water from wet food than they
do from drinking water. Plus you avoid a ton of crappy things they put in a
bunch of dry foods.

I feed mine Wellness Core and they love it.

~~~
ianai
I had a lot of success switching a cat to a wet diet. It cleared up many
health issues for her. Dry food is their junk food.

~~~
digler999
what about their teeth ? I've heard, at least for dogs, that the crunchy dry
food helps keep their teeth healthy

~~~
idunno246
thats an old wives tale. And if my cats teeth are any indication, a dry diet
didn't prevent any problems

Granted, there's no proof that wet is better, there's just a ton of anecdotal
evidence that dry food leads to dehydration and kidney issues. I had to switch
entirely to wet due to diabetes. Surprisingly, fancy feast classic is one of
the most recommended foods.

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StavrosK
My cat is completely blind, making her an ideal test subject for a homemade
cat feeder, but she also doesn't overeat, so I just leave three days' worth of
cat food in her bowl and she eats a bit every so often.

~~~
fn42
I'm surprised to see this is the only comment mentioning leaving a bowl of
food out 24/7\. This is how it's done at every shelter I have volunteered at
(and how I do it at home) - the cats should always have access to water and
some form of food. The wet (canned) food is what you have to be more careful
with because the cats will compete for it.

~~~
pweissbrod
Yep. We tried this before making the automated feeder. Gave it a 2-week trial
period. The initial reaction was surprise and delight with the abundance of
food. Initially they decided to eat 3-4X what I normally feed them twice a
day. I was hoping once the initial party tapered down they would get sensible.
Two weeks in I had 2 happy tigers and two very sluggish fat sad tigers that
did pretty much nothing but eat and poop. And Oh man the litter boxes were a
nightmare. I needed to clean them 3x day to keep up. I never figured out a way
to get _all_ tigers to be responsible with open buffet policy.

~~~
mahyarm
It depends if they went hungry at some time in their life.

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Tempest1981
What is the code trying to do?

Sweep left (food starts falling), wait on average 90 sec (food gone?), sweep
right, wait 85ms.

Then does it stop, or repeat the loop (until the outlet timer turns it off)?

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rrauenza
I think left is closed. So it starts by issuing the close command, waiting a
random amount of time, opening, delaying 85ms, then restarting the loop by
closing.

The random sleep seems unusual, though -- I would have normally done
delay(random(180 _2)_ 1000) -- is this a particular idiom with a benefit I
don't know about?

~~~
Tempest1981
So the intent is an 85 ms burst of food, every couple of minutes -- that makes
more sense.

The initial "close" threw me. Is the door initially open? Or are we just
jamming it shut and stressing the servo?

~~~
rrauenza
I assumed it was some kind of fail safe... Always start the loop in the closed
position. In case the Arduino got reset mid cycle...

~~~
Tempest1981
I wonder how often power shuts off during the delay(85 ms) time window.
Statistically maybe a 1 out of 1000 chance.

Probably more likely to shut off while opening/closing the door -- in those 2
loops (2 out of 1000?). Assuming an average main loop of ~85 seconds.

Kitty jackpot!

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agentgt
I would love to build more devices but the thought of installation always
bothers me. I always hate having to hang things on a wall. It requires either
finding a stud that is close by or using a crappy dry wall screw or molly
screw.

I'm particularly unlucky because I live in an ancient house so studs are never
ever close by and all the walls are plaster so that means 1 inch hole with a
molly screw (with chips of plaster and dust and follow up vacuum job... god
forbid you ever take the thing down because now you have to patch the hole
back up).

There has to be better solutions to attach things to the wall (and yeah I have
done the whole velcro command strip thing as well).

~~~
cr0sh
If you had real drywall, an alternative to a toggle or molly screw would be to
drywall anchors; there are two types.

One type is fairly common (and might be able to be used with plaster - maybe)
which has a plastic insert you install into a drilled hole, then when you
thread the screw into it, it expands to wedge itself in the hole. IIRC, the
largest of these can hold about 30-50 lbs in drywall (probably less in
plaster).

The second type uses a large threaded insert; the hole you drill for this is
typically larger than the screw which threads into it, but the anchor can hold
much more weight (up to 150 lbs per anchor in drywall). I don't think they can
be used in plaster, though, as they are meant to thread into the drywall.

I've used both successfully for a number of projects in my house; I have an
entire wall (about 12 x 8 feet) of bookshelves (using shelving standards and
melamine shelving) held up by the threaded anchors (hundreds of pounds of
books). I have used the expanding anchors for heavy items like large pictures
and mirrors, among other items.

The major downside with any of these anchors, though, just like molly or
toggle bolts they leave larger holes which need to be filled if you move the
item. Hence, you typically only use them for items which will rarely, if ever,
be moved.

~~~
jaclaz
For drywall, for lighter weights, let's say pictures, mirrors, not book
shelves, there are actually self-drilling and self-threading anchors, you
don't need a drill, only a power screwdriver, there are both metal and nylon
ones:

[http://www.colfert.com/Public/img/catalogo/products/zoom/img...](http://www.colfert.com/Public/img/catalogo/products/zoom/img_205201011526.jpg)

[https://admin.abc.sm/upload/1115/catalogodinamico/prodotti/H...](https://admin.abc.sm/upload/1115/catalogodinamico/prodotti/HZ.jpg)

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Waterluvian
Is foraging actually natural? Don't cats kill their meal, leaving it all in
the same place?

Sounds more like an excuse I'd give my wife for why I solved the tampering
problem by introducing a mess problem.

~~~
pweissbrod
Actually making cats employ more hand/eye coordination to get their food is
considered a healthier alternative to just laying it in a bowl. For example:
[https://www.google.com/search?q=cat+challenge+bowl&ie=utf-8&...](https://www.google.com/search?q=cat+challenge+bowl&ie=utf-8&oe=utf-8#q=cat+challenge+bowl&tbm=shop)

~~~
Waterluvian
Makes sense. Pulling the nutrients out of a rodent carcass would take
considerably more effort and paw eye coordination than just eating kibble from
a bowl.

I was more focused on the "foraging" concept with regard to cats. I don't
think cats forage.

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Zachery
In nature, the cat would wonder and "forage" to find prey to eat.

Years ago we rescued a barn cat, she would wonder all over the area to find
food (few mi radius): birds, mice, etc.

~~~
Waterluvian
Yeah. I guess now I'm just being pedantic on foraging vs. hunting. =)

Barn cats are so cool! Little murderfloofs with their instincts well intact.

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elif
Cats will get cat acne if you don't clean their food dish... or force them to
eat off of the floor.

~~~
milesokeefe
Interesting, I had never heard of that. Here's some more info on it:

[https://en.wikipedia.org/wiki/Feline_acne#Causes](https://en.wikipedia.org/wiki/Feline_acne#Causes)

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leot
(Shameless plug)

CleverPet Hubs work with cats, too!
[https://www.youtube.com/watch?v=lzXwrXEkmHM](https://www.youtube.com/watch?v=lzXwrXEkmHM)

Also, there have been rumors that the Hubs will be user-hackable in short
order. And they use Particle Photons in any case ...

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mplewis
OP said he got "sticker shock" from shopping for automated cat feeders, but...
how? The link he posted shows plenty that are $30. And the really well-
reviewed gravity feed ones are $60 at most.

~~~
pweissbrod
Yeah that was lazy work on my part. These pet feeders are quite reasonably
priced. But i was looking for something with programmability. I still want to
feed my tigers breakfast. I just want them to be OK with me sleeping in. So
the compromise is to have something that disperses very small amounts of dry
food at unpredictable intervals to keep them entertained and have a light
appetizer while dad gets another 45 mins sleep. The feeders capable of doing
that level of configurability started at $150 and they were quite impressive
but I personally felt compelled to make something fully programmable for the
way my house works. But youve got a good point here so I will update the link.

EDIT: the link I was talking about was thhis: [http://www.super-
feeder.com/](http://www.super-feeder.com/) It is very cool if money is not an
object to you

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BlytheSchuma
If only he had another less creepy pet name for his cats.

"Eat it up! Eat it ALLL up my little Tigers!"

~~~
pweissbrod
Sorry I creeped you out man. My cat strongly prefers the word tiger as his
reference. I think is cousin is an ocelot or something

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pweissbrod
OP here. As my friends have pointed out this wont work so well if you have a
dog :(

~~~
jaclaz
Well, it won't work with cats either, it will take anything between one
nanosecond and 15 seconds to rip open the thingy after having taken it out of
the wall (high as you might hang it). Compare with this recent post (the OP
there maybe overdid it a tad bit, still...):

[https://news.ycombinator.com/item?id=13230904](https://news.ycombinator.com/item?id=13230904)

~~~
jasone
I went through a similar process in 2003 with two cats that begged incessantly
for food. I had to bolt the feeders (of different manufacture and style) down
to a sheet of melamine and add thin metal shielding at the front to prevent
the cats from reaching up the chute to the auger, but IMO Furiosa's feeder is
grossly over-engineered due to leaping from various half-baked initial
anchoring attempts directly to a doomsday device. In any case, our collected
experiences suggest that cat feeder manufacturers do not adequately field test
their devices.

~~~
jaclaz
Yep, or maybe we have _smarter_ or _more persistent_ cats.

Anecdotally, once I had two cats that I "trained" to use a catdoor I had just
installed.

Cat #1 learned to use it in like three times I guided him thought the thingy.
Cat #2 simply couldn't grasp the idea and after like 100 attempts I gave up.

Later I heard "boom, boom, boom, boom, boom, tlatlac!", cat #2 never learned
to use the catdoor "properly", or maybe he had some vision defect, cannot
really say, but he got that it was a way in so it simply went head in on the
whole door (from left to right in 15 cm steps) until he got through the cat
door.

One way or the other, he got in.

~~~
mattkevan
One of our cats thought velocity was key when entering through a catflap. He'd
use most of the garden as a runway, hitting the door at full speed with a
BLAM! that could wake you up at night.

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wcummings
Hope it doesn't kill your cat. Doesn't seem like something I'd want to "hack".

~~~
pweissbrod
Dropping dry food on the ground stands little chance of killing tigers.

In the event of a malfunction and all the food is dropped I believe the tigers
will actually throw a party.

In the event the tigers die from overeating then I am a terrible tiger dad and
they die a happy death.

I do not know how to hack a tiger per se but I like tigers. Which is why I
built this. So I dont see myself intentionally putting them in any form of
danger.

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Fnoord
I prefer to drop the food in their bowl instead of on the ground. Less messy.

