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:
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:
Remove these ads by
Signing UpStep 1: Tools and materials
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
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
Visit Our Store »
Go Pro Today »
m4 is only used to replace some variable/register names. Feel free to update it!
Happy hacking!
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...
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. :)
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. :)
Thanks!
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
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.
www.azhumane.org/PDFs/behavior/cats/felinebodylingo.pdf
You and your beautiful model hit it out of the park!
I love this project.
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.
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!
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.
Pretty brilliant regardless. c:
thanks
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.
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!
Thank-you!
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!
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
You have to be careful with the sub micros, they're really awesomely tiny but I think their torque is significantly reduced. Either the HXT900 or the TG9e have 1.5-1.6 Kg-cm torque whereas the SO361 sub micro that hobbyking sells ( http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=3715 ) has only .3 Kg-cm torque (or so). That's 5 times as less!
I've used the SO361 sub micro in a bunny mask costume with movable ears out of paper and fur (and glue), It mostly worked but I found that sometimes the motors weren't powerful enough to overcome the momentum of a moving ear, causing it to overcompensate and then start to go back and forth effectively making the ear 'wobble' (at least that was my theory on why it was wobbling).
If you are feeling adventurous and want to try the sub-micros, I would suggest at the very least using some sort of plastic arm instead of the metal bracket and either taking out middle portions of unused acrylic or just making the top front facing ear out of wire. I think the code should work without any change.
If you guys run into any problems and need help feel free to give me a message and I'll do what I can to help! If you could post some pictures after your build is complete, I would also appreciate it.
Good luck!
Maybe I'll do this for "version 2.0".
Depending on what servos you actually get, their torque rating may be different than the value given for the HXT900, so you might need to experiment.
any experience with this?
what kind of battery life have you been getting?
built any moving tails yet?
thanks!
-matt
its difficult to do anything serious with.
Efficiency is only like 0.5%, and
you have to use up a bit of it fighting a return spring.
You must use a return spring to get push pull action, otherwise
it only pulls.
Thats why you dont see a lot of serious apps out there for it.
We gave up and went to a small hobby motor / gearbox.
abetusk went the right way.
The servos that I use are reported to draw 750mA maximum (check out some analysis done here: http://homepages.paradise.net.nz/bhabbott/Servo.html ). Assuming all four servos are drawing at maximum continuously, that's 3A (thus why I chose the 3A DC-DC regulator). The battery I use is 900mAh so that gives an approximate lifetime, if all four servos are in continuous use, of 18 minutes. So, at worst, lifetime should be about 20 minutes, at best maybe an hour or two? I have not done real testing in this regard so I'm not sure what kind of battery life you can expect.
As to the moving tails, all the videos online that I've seen don't give the amount of expressiveness that I would want and I don't see how to make them any better.
I have the hardware ready, just needed some inspiration on how to actually build the ears!
it would be really awesome to do something like this on a fursuit!
I was wondering do you sell this? if so How much? I'll buy you one.
http://frontiernerds.com/brain-hack
Arduino code for the Neurosky Mindset.
http://makezine.com/26/primer/
Enjoy!
I also found this project which actually does connect to a MindWave:
http://www.thingiverse.com/thing:13390
http://paperbits.net/cat
Maybe there are higher prices servos that aren't as loud?