kears_shot8.png
kears_shot6.png
kears_shot2.png
kears_shot7.png
  I saw the demo video for the neurowear "necomimi" brain controlled cat ears and I thought they were pretty awesome.  I'm just starting to learn electronics and I thought a fun project to start out would be making my own version.  Sadly, I don't think I'm adept enough yet to take on making my own EEG and I don't think the EEG's that are available are very reasonably priced, so I settled for having a button input to control the cat ears.

  I wanted to build something that wasn't too expensive and was easy enough to be done in a sitting or two.  I picked out some cheap servo motors, some craft supplies, spent a weekend or two developing code to control the servo's from a microcontroller and after much trial and error, I built some kitty ears that I think are pretty decent.

  Here's a video of my lovely assistant using the Kitty Ears:



 
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Step 1: Tools and materials

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Tools:
  Safety glasses
  Face mask
  Hot glue gun (and hot glue): I picked one up for under $5 at a local Michaels Craft store.
  Dremel:  $18.99 at Harbor Freight Tools (http://www.harborfreight.com/professional-4-speed-rotary-tool-kit-40457.html)
  Drill: $18.99 at Harbor Freight Tools (http://www.harborfreight.com/3-8-eighth-inch-variable-speed-reversible-drill-3670.html)
  AVR Programmer: USBtinyISP AVR Programmer Kit from adafruit.com $22.00 (http://www.adafruit.com/products/46)
  Soldering Iron
  Wire strippers
  Wire cutters
  Flex tubing: $2.88 from WalMart

Materials:
  ATTiny13: $1.09 from mouser.com (http://www.mouser.com/ProductDetail/Atmel/ATtiny13V-10PU/?qs=sGAEpiMZZMvu0Nwh4cA1wUVlLgw9m2DPt6IffusRY5Y%3d)
  4x micro servo motors (hxt900 compatible): I found a few different places to get these.  I've had good luck with hobbyking, but there's also dealextreme.com, suntek.com and ebay.
    http://www.hobbyking.com/hobbyking/store/__9549__Turnigy_TG9e_9g_1_5kg_0_10sec_Eco_Micro_Servo.html
    http://www.hobbyking.com/hobbyking/store/__662__HXT900_9g_1_6kg_12sec_Micro_Servo.html
  Proto Board:  $3.19 from Radio Shack (http://www.radioshack.com/product/index.jsp?productId=2102846#)
  Wire: Black and Red are good choices for colors
  Pushbutton:  I like the sub mini pc mount pushbuttons (4 for $1.00) (http://www.allelectronics.com/make-a-store/item/PB-126/SUB-MINI-PC-MOUNT-PUSHBUTTON/1.html)
  1k resistor: (brown black red)
  Solder
  LiPo battery: Anything that will be able to supply 3A worth of current.  Here's a good choice from hobbyking for $5.33:
   http://www.hobbyking.com/hobbyking/store/__9276__Turnigy_800mAh_2S_20C_Lipo_Pack.html
  LiPo battery charger:  You might want to shop around on ebay, but Hobby King sells one that I've used and seems to do the job here: http://www.hobbyking.com/hobbyking/store/__8247__Turnigy_2S_3S_Balance_Charger_Direct_110_240v_Input.html ($11.44)
  DC-DC regulator: $4.90 from hobby king (http://www.hobbyking.com/hobbyking/store/__10312__Turnigy_5A_8_26v_SBEC_for_Lipo_.html)
  Stiff plastic headband: preferably black.  I found one at a garage sale, but here's a cheap source I found for them online ($7.49 for 12) (http://factorydirectcraft.com/catalog/products/2346_1302_2533_2297-21165-1_black_plastic_headbands_12pcs.html)
  Black fur, white fur and grizzly black fur cloth:  I found these three at Joanns for about $5-10 a yard each
  Glue for glue gun
  Sheet of acrylic (1/8" should do): Picked one up for around $5 at the hardware store
  Metal brackets:  I used mailbox brackets that I picked up at the hardware store for $7 or so
  Gorilla glue
  

Optional Materials:
  Grinder
  Sewing Machine
  Black insulating tape
  Sand Paper

1-40 of 72Next »
OngakuShima says: Mar 11, 2013. 1:11 PM
Thanks for the link. I may be needing some help, but it will be some time... Right now I don't have m4 installed on my ancient Ubuntu. M4! That's a blast from the past.....
abetusk (author) in reply to OngakuShimaMar 11, 2013. 2:23 PM
Yeah, sorry about that, I just picked the first thing that I found worked for coding in assembly. I had to go to assembly because the C was getting too big for the ATTiny13.

m4 is only used to replace some variable/register names. Feel free to update it!
OngakuShima says: Mar 11, 2013. 6:26 AM
Very cool. Wondering where I might get the source code to the hex file.
abetusk (author) in reply to OngakuShimaMar 11, 2013. 7:21 AM
Whoops, sorry about that, I have a link to the ihex file but not the source tree. The source is here and all open.  PM me if you run into any problems and I'd be happy to help.

Happy hacking!
DividersMaker says: Jan 18, 2013. 10:35 PM
One word: awesome!
dario.massaro says: Dec 21, 2012. 7:45 AM
@Abetusk: Your build is awesome. I think it looks nicer and appears more functional than the commercial alternatives readily available. Do you think you could adapt it to function and look the exact same way but with an EEG/Mind Read spec instead of push-buttons??
abetusk (author) in reply to dario.massaroDec 21, 2012. 12:55 PM
It is possible and actually already been done. See here: http://paperbits.net/cat . I don't have any plans on hooking up an EEG to it, but you're welcome to experiment!
dario.massaro in reply to abetuskDec 21, 2012. 1:12 PM
Thanks for the details and the awesome project. :)
Luziviech says: Oct 4, 2012. 12:54 PM
Did i mention that this instructable is awesome? It's the first project, i try to use for my own project of a catsuit using my abilities of chainmail, taylorship and tinkerer (she's got a cat-notion and wants sumthin to strip).

I find the ears get more structure, if you make em from the top-part of a plastic-bottle. We got this Orange-juice from Lidl here in Germany and its bottles are made of thicker plastic and on top is a big button. I used the dremel to grind the cone of the bottle and cut into three pieces and took two of them as ear-bases. The bottles cone is formed round and so i got ears that are pointing forward. I put rubber foam on the back, cut it out for the motors and cut the edges down. Now i got sum garfield-like ears...
abetusk (author) in reply to LuziviechNov 16, 2012. 1:04 PM
Do you happen to have a picture of the plastic bottle you're using? Maybe a link to a picture of the container?
goldenshuttle says: Nov 14, 2012. 11:18 PM
neat work. and your assistant is hot cat.
pensativo says: Apr 26, 2012. 9:55 AM
There is an option that will keep you from having to do some of the wiring. I found this a few months ago and I'm loving it for things like this.
http://www.pololu.com/catalog/product/1350
It's a tiny servo controller that lets you run scripts. It can run up to six servos, so two of headers on it can be converted to inputs for hooking up switches. :)
pensativo in reply to pensativoJun 22, 2012. 10:21 AM
Okay, so this is what you want to do:
You get your little maestro board. It has six servo slots, which is perfect for this project. Use the first four slots for the ears (0 and 1 for the left ear and 2 and 3 for the right ear). Next you will designate the remaining two slot for the control switches. Buy the "partial kit" and just populate the first four servo header positions and the two pin power header. Reference the manul http://www.pololu.com/docs/0J40 for the locations and specs on these. You designate servos and inputs like switches in the sofware http://www.pololu.com/docs/0J40/3.a . Once you connect the board to your PC via the USB you will see how to configure it pretty easily. I say to leave the last two headers of so you can solder the switch wires right to the board. Te me that would be easier. All you need to set up the switches is two 1-100k resistors for pull-ups in order to keep from getting false signals. Check here for info on hooking up the switches. Now, all you have to do is plug in all your servos and the battery. Just make sure that you don't plug in a battery that is of a voltage that is too high for your servos, they won't last you very long if you do. I suggest that you write down what channels you use for what as in 0-left ear up/down, 1-left ear left/right and so forth. Now you can center all your servos and save those settings. You are now ready to start scripting your cat gestures. It's all loop based, so what you want to do is write subs for each gesture and have the button events jump you into the appropriate sub. Let me know how it works out for you. Tweaking the scripting is my favorite part, so I won't spoil that for you. :)
Owlflight in reply to pensativoNov 1, 2012. 8:56 AM
Thanks for posting this! I liked his use of servos, but I had a different project in mind. Your link looks like an excellent place to go.

Thanks!
JCLSD says: Aug 27, 2012. 8:05 AM
Hello there,

I found your k-ears pretty sweet, so I gave it a try!
But I have no response from the push button, and the servos are only moving when puutting the power ON, kind of random, and they don't come back in a "home position"...
I checked the circuitry several time, continuity and all, and as it's very simple I was asking myself: could it be a program error?, I'm very new at controllers, but I had the very same message than on your screenshot when putting the .ihex files on the t13...

any idea would be more than welcome, I can't wait to have those on my head :-)

cheers
abetusk (author) in reply to JCLSDSep 23, 2012. 8:50 AM
JCLSD,

Sorry for the late response. I hope you worked everything out. If you didn't, feel free to message me and I'd be happy to work through the problems with you.

If you do message me, if you could provide some pictures of your setup so that I can see what you're doing, along with the specific pars you're using (servo motor model, avr chip, etc.), I'd appreciate it.
Luziviech says: Sep 21, 2012. 1:08 PM
hm, i rather neglected buying brackets. I used steel band, left over from my scissor-hand-projects. You can find it at any building site, just look out for material spaces: the palettes are mainly secured with such bands and it's lying around after the workers opened the palettes with metal shears.
G1rlsgotrhythm says: Jun 24, 2012. 7:11 AM
Awesomesauce! :3 I'm trying to make this in half term as I want to learn electronics. It's very cute, I love it!
pensativo says: Jun 22, 2012. 10:42 AM
Hey, check page 2 of this doc. Feline facial expressions.
www.azhumane.org/PDFs/behavior/cats/felinebodylingo.pdf
You and your beautiful model hit it out of the park!
I love this project.
tbraywater says: May 30, 2012. 9:00 AM
You have a target board hooked up to the USBTinyISP (see http://www.instructables.com/files/deriv/FTT/KLK6/GYUY0IJZ/FTTKLK6GYUY0IJZ.MEDIUM.jpg ).

I'm trying my hand at this, but I have *no* electronic skills... could you please point me to a diagram for this target board?

Many thanks.
abetusk (author) in reply to tbraywaterJun 1, 2012. 4:41 PM
The target board is just mapping the appropriate pin on the ATTiny13 to a 6 pin header. I've found this page to be quite good for a general description and help:

http://www.evilmadscientist.com/article.php/avrtargetboards/print

That page has the standard 6 pin header layout and the pinout (with the appropriate pins) for the ATTiny13 chip.

You might also want to check out this instructable:

http://www.instructables.com/id/Ghetto-Development-Environment/step3/The-Programming-Cradle/

It looks like he made a cradle for the ATTiny13 that's small and you could probably deduce how to make one of your own from that.

One note of caution: The programmer from ladyada, that you have to assemble, needs a jumper instead of a resistor in order to work properly. In her 'Solder it!' instructions here:

http://www.ladyada.net/make/usbtinyisp/solder.html

There's a step where she says:

"If you are using the UsbtinyISP with a SpokePOV kit, install R4 and R7 (1.5K) as well. If not you may want to switch these resistors for jumpers (see the second photo for a 'finished' shot) as it will mean that target boards with loaded pins can be programmed."

Since you'll be using the UsbtinyISP as a stand alone programmer and not for the SpokePOV, you'll need to replace those resistors for jumpers.

If you have any more problems, feel free to private message me and I'd be happy to help if I can.

Good luck and remember to post pictures!

PhantomX999 says: May 20, 2012. 5:12 PM
ok, this is my first electrical build ever and i need to ask. how do you charge the power pack?
abetusk (author) in reply to PhantomX999May 21, 2012. 12:27 AM
You'll need to get a LiPo battery charger. The above build uses a 2s 7.4V batte
ry pack, so you'll need a charger that can handle a 2s battery pack. Hobby King
has one here:

http://www.hobbyking.com/hobbyking/store/__8247__Turnigy_2S_3S_Balance_Charger_Direct_110_240v_Input.html

but you can always shop around yourself by putting in 'LiPo battery charger' in
either Amazon or Google.
PhantomX999 in reply to abetuskMay 21, 2012. 5:44 PM
ya, might have wanted to added that in ''JIC''. the only other thing i might change is put all the stuff together that you got from hobby king. so when people order the parts as they go, not to put out multiple orders and having to pay for more than one shipping price.
ReCreate says: May 15, 2012. 11:15 AM
Even though I'm a furry, I have a little bit of difficulty getting what this is for... What is this for? O_o

Pretty brilliant regardless. c:
Hom3rSimpson says: May 15, 2012. 11:01 AM
You list where i can find everything but an assistant? Where can I find one like yours and how much do they cost? (Can they be persuaded with animatronic cat ears?)
Dusk Shadows says: May 12, 2012. 7:21 PM
wow these will go great with my brothers cat bell i have to make these for his birthday he will love them and maybe he wont beat me up for an hour yayayayayayayay!!!!
thanks
p3av8or says: Apr 25, 2012. 3:56 PM
This is my first time using perfboard, and I'm having trouble figuring out what bridges you've made on the other side of the board. Sorry for the noob questions, but I don't have an electronics background. Thanks!
abetusk (author) in reply to p3av8orApr 26, 2012. 8:48 AM
I used the proto board I got from RadioShack (online here: http://www.radioshack.com/product/index.jsp?productId=2102846# ) and not perfboard. The main difference is that the copper traces on the proto board model a breadboard whereas the perfboard has isolated copper pads per hole. I've found perfboard to be messy and clumsy so that's why I used the proto board.

I would suggest getting a simple setup running on some breadboard, i.e. connecting the power to the regulator, the regulator to the circuit, wiring at least one servo out of the micro, connecting the button and testing before proceeding further. Once that's done, you'll have a good understanding of how to connect components together. You can use either protoboard or perfboard for connections, I just prefer protoboard as I find it easier to work with.

Send me a private message if you get stuck and I'll do what I can to help.
rhoult says: Apr 5, 2012. 12:13 PM
I'm a little confused here. Is there a simpler diagram for wiring this? i'm building this for a friend and am stuck on this step. Is there any help you could offer?
abetusk (author) in reply to rhoultApr 5, 2012. 6:34 PM
The above is a simple circuit showing the connection between the microcontroller, the servos and button. It doesn't include the regulator, battery or connection thereof. There should be four lines coming out of the ATTiny13, each going to the signal line of the corresponding servo. One line out of the ATTiny13 is attached to a button with a pullup resistor.

Each of the servos needs to be connected to the power line and grounded, along with the button, pullup resistor and microcontroller. The power should be from the regulator that provides a steady 5V from a lithium ion battery. The analogy is a wall wart: You plug in the wall wart into the wall socket then plug in your device from the wall wart to provide the power you need for your device. The 2 cell lithium ion battery is like wall socket power and the regulator is like the wall wart.

The 2 cell lithium ion battery is needed to provide the amperage necessary for the servos and the regulator is needed to provide a steady 5v and service the amperage draw needed by the microcontroller and servos (mostly the servos). Using a 9v or AAs might work (through the regulator, of course) but I've run into problems, I think because the amperage requirements of the servos is too heavy.

To figure out what color wire from the servo corresponds to power, signal and ground, I found the following web site useful: http://www.societyofrobots.com/actuators_servos.shtml .

I take it you're a beginner to electronics and so this stuff might be a little confusing. I hope the above addressed the confusion you had, but if it didn't, feel free to send me a private message to discuss this further.

Good luck and make sure to show pictures after you're done!
MountainBlueFoxJoe says: Mar 18, 2012. 10:08 PM
Wow ' but I had this technology for years and the parts I use don't exist . There all hand built drivers and are in all of my suits plus the tail even moves and lights up at tip also I'm glad there's others out there who are in to animatronics and just not me , Keep up the good work . Mountain Blue Fox Joe also crazyjoe1952 .
rhoult says: Feb 28, 2012. 6:40 PM
This might sound a little noobish, but what's the black box that you hooked the microcontroller up to to calibrate it?
abetusk (author) in reply to rhoultFeb 28, 2012. 10:31 PM
I'm sorry, I don't know what you mean. The calibration step that appears in this instructable whereby the servos are aligned on the headband? Or do you mean some other type of calibration?
rhoult in reply to abetuskMar 4, 2012. 9:04 PM
sorry, i found out what it was i was inquiring about, but how did you wired the micrcontroller? I'm a little inexperienced in the whole microcontroller thing...
Uptonb says: Mar 2, 2012. 4:26 PM
Congrats on being a finalist, and good luck!
jeanlafete says: Mar 1, 2012. 12:59 AM
A+ on Innovation! Your assistant is a doll and loves the expressions she does with the ears. Love to see more and how well the ears hold up. I would love to built, unfortunate I don't have the free time:-( Keep up the great work!
Thank-you!
Oscar1986 says: Feb 25, 2012. 1:22 PM
This looks awesome. I went to buy the USBtinyISP AVR Programmer Kit, but it says it may or may not work with Windows 7. I have Windows 7 Home premium do you know if it'll work? or should I look for another one? and if so which one do you recommend?
abetusk (author) in reply to Oscar1986Feb 27, 2012. 7:59 PM
I believe that Adafruit is just hedging their bets and that it's not so much that it might or might not work on Windows 7, but that they haven't tested it on Windows 7 and can't cofirm it's functioning as expected. I just did a brief search on the forums to see if anybody had any problems with Windows 7 functioning with their USBtinyISP and it looks to be alright. You should do your own homework to confirm but I would bet that it would function fine on your system.


If you do end up going with Adafruit's USBtinyISP, make sure to follow the build instructions here ( http://www.ladyada.net/make/usbtinyisp/ ) with special attention to step 11 here ( http://www.ladyada.net/make/usbtinyisp/solder.html ) where you need to replace the resistors R4 and R7 by a jumper (see also http://forums.adafruit.com/viewtopic.php?f=20&t=15045 ). When I first bought the USBtinyISP, I found this instructable to be helpful as well ( http://www.instructables.com/id/Ghetto-Development-Environment/ ).


There are alternatives but I haven't used them so I can't attest to their reliability. Here are some li
nks, in no particular order:


http://www.seeedstudio.com/depot/avr-usb-programmer-p-696.html
http://www.pololu.com/catalog/product/1300
http://www.sparkfun.com/products/9231


You will need to make a target board for the target chips. You can see my very rough one in the 'Programming the ATTiny13' step of this instructable. You might be able to find premade target boards, if you wanted, by searching around. Just make sure that they're ATTiny13 compatible.


Here are some links that I found helpful when first starting out:


http://www.evilmadscientist.com/article.php/avrtargetboards
http://www.ladyada.net/learn/avr/programming.html


And just for completeness, a link on avrdude and programming:
http://www.ladyada.net/learn/avr/avrdude.html


and a tutorial on avr-gcc:
http://iamsuhasm.wordpress.com/tutsproj/avr-gcc-tutorial/


I've had good luck with the USBtinyISP. Adafruit is really good about responding to problems on their f
orums and I've been happy with mine. It may seem a little daunting at first but all you're really doing
is solerding a kit (at worst) and connecting point 'A' to point 'B'.


There is also the route of using an Arduino with an ISP shield to program your AVR's. EvilMadScience has one here ( http://evilmadscience.com/productsmenu/tinykitlist/253 ). There's also some instructables on the subject here ( http://www.instructables.com/id/Turn-Your-Arduino-Into-an-ISP/ ) and a tutorial here ( http://arduino.cc/en/Tutorial/ArduinoISP ). If you're feeling more adventurous, here's a HackADay article on it as well ( http://hackaday.com/2009/07/15/avr-isp-programming-via-arduino/ ). I haven't done this myself but maybe this would be easier for someone more familiar with Arduino's.


Good luck!
ignatzart says: Feb 26, 2012. 8:20 AM
My granddaughter and I are building these for her next Anime-con. I truly appreciate your clear instructions. We wondered if we could use submicro servos to cut down the bulk? We are new to this stuff so I don't know how to match the bits. What are the specs we would look for to substitute servos?
One thing though, the source you give for the ATTiny13 has a minimum order of 940 pieces YIKES! So we got one from Digikey.
Jen
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