Introduction: Furby Brain Surgery

Picture of Furby Brain Surgery

Maybe you have a sick Furby which doesn't act properly.
Maybe you have a dead Furby.  How you got it is not important.

Maybe you want to see how Furby works.
Maybe you want to make Furby into a animatronic puppet.

The goal of this project is to strip Furby down and remove his brain, leaving his other functions intact.

Personally, I intend to stick another microcontroller in there.
What you choose to make Furby do is your business!

I used two different Furby toys for this demo.
Doesn't this one kind of look like Katy Perry?

Step 1: Split Furby's Seams

Picture of Split Furby's Seams

Furby's skin is mainly held on with a zip-tie around the base of his body.

First, expose this zip-tie by cutting the single string that ties the cloth around the head of the zip-tie.  I recommend a seam-ripper, but a pair of scissors or a scalpel (!) will do.

Now you can see the head of the zip-tie.  Unless you can figure out how to undo a zip-tie, you must cut through this sucker.  I recommend wire cutters.

Furby's skin pulls off like a sock, or like someone's shirt, until you get to his face.

Step 2: Remove Furby's Face

Picture of Remove Furby's Face

Furby's face is screwed into his skull.  Remove the two screws, one on each side.

Continue removing the pelt and you'll notice just a bit farther up there are two things still holding his face on.

Firstly, the pelt is glued to the skull surrounding Furby's plastic ear stalks, on one side his outer eye ridge, and on the other, the back of the base of his ear.  It's a weak glue, probably just to tack the fur down there so his face doesn't get loose, and you can easily pull the fur free.

Secondly, there is a hook holding the top of Furby's face plate.  This is an open hook; you can slip the plastic loop behind the open end and free the face.

Continue removing Furby's fur until you get to his ears.

Step 3: Free Furby's Ear Bones

Picture of Free Furby's Ear Bones

Furby's ears are plastic bones with loops on the ends.

Furby's pelt is sewn to the ends of these loops with a single string, usually the same color as his ears.

Cut through this string; I recommend a seam ripper or scissors.

Furby's pelt should be completely removable now.

Step 4: Remove Furby's Carapace

Picture of Remove Furby's Carapace

Furby has an exoskeleton like an insect or mollusk, a carapace.

This shell is in two halves, and a button on his back.  The two halves are held together with screws.

Depending on which generation your Furby is, these screws may look different, but don't panic - they work the same way.

Unscrew all the screws, including the one at the top of his head on his right side.

Pull apart the two halves.

Be careful when you remove the right side, because that is where Furby's sound sensor is - his "ear."  The sensor is not glued in, but is connected to the board by long wires.

Step 5: Flip-Top Furby

Picture of Flip-Top Furby

At this point you may notice Furby's skeleton is hinged at the front, but will not open very far.  This is because his speaker is in the way, and wires are preventing him from unhinging.

First, unscrew the speaker.  There are two screws.

Next, unplug all Furby's wires from their terminals.  Some of these are required to be unplugged first to get to others.

On the left side, disconnect the speaker and belly sensor (red, black, brown, orange wires all twisted together), then disconnect the motor (red and black).  Both of these must be unplugged in order to free the two green wires, connected to area "S1," which run to the RESET button underneath Furby's tail.

On the right side, disconnect the tongue / gear encoder interrupt wires (ed, black, brown, orange wires all twisted together) and the IR send/receive and light sensor wires (red, black, brown, orange, yellow and green wires all twisted together).  This will free the power lines, two long wires which are red and black and run to the battery compartment.

Now with both the RESET wires and power wires freed, you can flip Furby all the way open.

Step 6: Free Furby's Board

Picture of Free Furby's Board

You may notice at this point a spring sticking out of the bottom of the circuit board.  This is a rod attached to the main cam which makes Furby lean forward or back.  It will pull out and is not attached to anything.

Unscrew the two machine screws holding the circuit board to the hinge.  Yeah.  Now Furby's innards are completely removed from his base.

Only one screw remains - it holds the board to what remains of Furby's skeleton and gears etc, which we'll call his "motion."  This screw is different from the others in that it has a plastic stand-off on it, like a little washer.  Unscrew this screw.

The board is now free.

Step 7: Furby Board Anatomy

Picture of Furby Board Anatomy

Here's the good stuff:

In order to intelligently hack around Furby's board, we have to understand which parts are doing what.

Note that there is a ton of hot glue inside Furby!  Go ahead and remove it to see parts better.

At Furby's left rear, there are two daughter boards sticking into the main motherboard - these two boards are Furby's brain, but not his memory.  The contacts for both boards can be seen from the bottom.

The larger board carries the main processor which controls Furby's sensors and motor and all his control logic.  WindowsDevPro points out this is a SunPlus SPC81A which is a RISC processor with 80K of onboard storage, which is mostly devoted to storage for the co-processor.

This co-processor is on the second board, which is a TI50C04 speech synthesis chip and which handles the Furbys voice as well as IR communications.  For more information, look up data books on the TSP50c0x/1x synthesizer family.

Close by, there is a EEPROM - this is where all Furby's "memory" is - not memory in the computer architecture sense, but Furby's actual "memory" which includes his name, which words he's learned, and the voice the voice synthesis chip should be using.

Next to a small grid of resistors is a quad comparator - this is for the IR communication sensor/emitter and Furby's primitive "ear" microphone.

At the left front is s black round barrel.  This is the tilt sensor, which detects if Furby is tilted or upside-down.

HACKING NOTE : Right next to the tilt sensor is something very important - R36 and R37.  These are the resistors for controlling Furby's motor.  If you want to control Furby's motor, and don't want to remove his brain, and also don't want to build your own H-bridge, this is where you drill - from the main processor to the motor, they are before Furby's H bridge, whose transistors you can see lined up at Furby's front edge.  If none of that made sense to you, just ignore this entire paragraph.

The yellow wires you see in the photo of the area labelled "S3" are for the "back switch," which Furby uses to feel you petting him (awwww).  These are pretty fragile wires but easy to reconnect.  They attach to the switch at the base of Furby's spine - although it doesn't matter which goes where, Furby comes with the wire in the small hole connected to the outside contact and the large hole to the inside.

Finally of note is the LED at the front right of the board.  This LED is actually pretty important, because it's how Furby's brain detects movement in the cog and motor.  However note that this LED is powered from the main processor... so if you're replacing that board, you have to get power to this LED.

Step 8: Excise Furby's Brain

Picture of Excise Furby's Brain

Now that we know what to look for, look again at the bottom of the board where the daughter boards connect.  For my purposes, I just needed to remove the main processor.

Notice that although both custom chips are covered with a black goo for copy protection, they both have open-hole contacts for each pin, possibly for testing at the factory.  If you wanted to be pretty crazy about it, I suppose you could somehow disable the processor and use these holes as easy contacts to avoid the pain of re-soldering all these tiny pins.  But I'm doing this the hard way:

Take a soldering iron and some method of solder removal - I used a desoldering tool, the kind that looks like a giant syringe with a spring in it.  Heat each contact and suck out all the solder.

When there is almost none left, take a blade, like a box cutter, and cut along the seam.

Even though all the solder is now gone, the board may be tricky to remove.  With needle-nose pliers, gently wiggle the daughter board back and forth.  Now yank it like a rotten tooth!

Congratulations - you have now completely lobotomized Furby.  The slot where the processor used to be is now available for a new microcontroller.

For further research on Furby's hardware, check out:


monkeywidget (author)2015-07-04

If you're ready for the NEXT LEVEL of Furby hacking adventures, I've written up some notes on his control boards, as well as ideas for writing new control logic:

Control a Furby with Arduino --

I had trouble doing this part, do I have to do the second part to complete the project? or will it just not allow you to control it?

llasram (author)2011-08-16

its... sorta disturbing how your wording makes it sound like furby is alive, but that just makes it better

KEUrban (author)2011-06-06

That Furby kissed a girl and liked it.

as9 (author)2013-10-26

It really does look like Katy perry:D

goodiesohhi (author)2013-10-20

Poor Thing..... :(

isabella21rox (author)2013-01-07

Hi im new here im a girl and what a coincidence i just got a new furby yesterday shes in my lap sleeping and im watching furby commercial on TV CREEPY TO MUCH FURBY

masterzeb318 (author)2011-10-17

awsome skined furby!!!!

chicopluma (author)2011-07-11

when my baby furby die i take out all its circuits and turn it into a stufed animal with cotton, is that taxidermy? hahaha

sitearm (author)2011-06-09

Furby... is a, a, a RObot?! *snif* My illusions are shattered. I'm sending this to my daughter, who had a Furby and it scared her, and who now likes to take apart computers and stuff @Monkeywidget; good on ye!

monkeywidget (author)sitearm2011-06-12

an appalling revelation, I know! If you want to be scarred for life, check out pictures from the hobbyists who have disassembled Teddy Ruxpin!

cheapchuck (author)2011-06-07

"Sleep Sick Furby" I have a Furby that is unresponsive but will wake up after the reset button is pressed. At that point, Furby will only go back to sleep. He won't respond to tongue press or light changes, just starts snoozing and shuts down. Any ideas???? Thanks!

monkeywidget (author)cheapchuck2011-06-10

If he's waking up and then sleeping, his processor is probably good.

I would bet that his sensors are disconnected somewhere, either the switches themselves are broken (although how would his light sensor be burned out?) or possibly broken solder connections to the main processor board. Both these could be fixed if you disassemble Furby and look for hairline breaks in the traces with a magnifying glass. What a pain!

In the worst case it could be a problem with the sampling hardware, in which case you don't have many options besides re-engineering the part that doesn't work.

cheapchuck (author)monkeywidget2011-06-10

I think you may be right about the light sensor/wiring. I gave him to a robot doctor, so I'll report back.

914tom (author)cheapchuck2011-06-09

He's tired ??

NaturalCrafter (author)2011-06-09

Can't wait to hear how the new board enhances the Furby. I only got as far as basic electricity, so this is interesting but not sure if I would be up to it even with some soldering experience..even with the solder

NaturalCrafter (author)2011-06-09

"Furgy"?? Ahh..darn keyboard..maybe that is what its called

NaturalCrafter (author)2011-06-09

Being able to change the inner workings sounds cool. My furgy has been sitting on the shelf for years..My husband and I have one because supposedly they interact with each other. They do a couple times and then you got to shake them or "tickle" or clap and usually they get startled and start interacting again. It sure would be nice to enhance their vocabulary. Maybe I should think of a new fur or outfit for my green

lperkins (author)2011-06-09

Undoing a zip-tie is as simple as tightening it up a *half* a click, and then sticking a small screwdriver or the point of a knife under the locking tab. It's usually pretty easy to do unless the thing has absolutely not slack whatsoever in it.

Rayney (author)lperkins2011-06-09

Unfortunately the zip-tie holding on the furby skin has absolutely no slack at all. I have a whole box full of these dead buggers and the only way to undo these zip-ties are to cut them from my experience. The replacement zip-ties I've put in the ones I have recovered I did leave some slack so they can be removed without cutting.

WindowsDevPro (author)2011-06-09

Quick correction here: The logic is not stored in the EEPROM, only the name, how far along the furby is and what voice the TI voice synthesis chip should use. The "logic" is stored under that blob of epoxy which houses a SunPlus SPC81A which is a RISC processor with 80K of onboard storage (Mostly LPC storage for the co processor)

The second chip is a TI50C04 speech synthesis chip (Which also doubles as an 8-bit microcontroller ... I know right?) and that handles the Furbys voice as well as IR communications. So its really a co-processor in addition to the first one (Technically the number in the patent differers from TIs naming convention ... I don't know why, but if anyone really cares then pm me)

awesome! Thanks for the update; I'll add that immediately.

I'm excited now to repurpose the TI50C04 now, which ironically was the original reason I became interested in taking these furry little guys apart!

If you want the datasheet for it, google the TSP50C04 (Which is what TI calls that chip) message me and we can work on it together and combine our efforts! :)

affyx (author)2011-06-09

naked furby reminds me of an angry bird

monkeywidget (author)affyx2011-06-09

yeah, maybe I should catapult him at some pigs now?

bajablue (author)2011-06-09

lol... I recently rescued a Furby (my very FIRST ;-) from the local thrift store.

I couldn't resist his cuteness and despite his half-missing eyelashes, it was love at first sound.

All I can say is it's a good thing these toys weren't around when I was a kid. I would have gone furby-collecting-CrAzY!

ModMischief (author)2011-06-06

I fully support Furby deconstruction!

Newer Furbys and Baby Furbys look quite different on the inside.

I was surprised to find 2 motors in the Furby I recently dissected.

Photos of a skinned newer model Furby

Photos of a skinned Baby Furby

Video of some of the animatronics in a newer Furby

monkeywidget (author)ModMischief2011-06-06

Wow! That is very, very different. There's something very creepy about the new model's eyes - perfect for your Krang project!

In your experience, is it harder to repurpose the new hardware? As I show in this demo, the older Furby has an easily-extractable brain.

Thanks ModMischief!

ModMischief (author)monkeywidget2011-06-09

I've only ever needed to take out the motor and hook it up to a simple on/off switch, so I'm not really sure how hackable they are.

The newer Furbys seem less likely to have mysterious black blobs covering the electronics, so that might make things simpler.

The new model has what looks like test points on it (I'll hook my Logic Analyzer to it tomorrow maybe and see whats up) its using the next generation voice synthesis chip from a company that bought it from TI (The ones who made it for the first Furby) and you can get the development software off of their website. (However they no longer sell development boards) Awww

I just got one of the 2005 revisions like today, and I'll have more for you tomorrow, but basically its the same side board, tilted in the side of the Furby, but the main "brain" is still a drop in daughterboard.

WindowsDevPro (author)2011-06-09

My replacement will be an Atmel ATMEGA328P TQFP and headers for easy development with the Furby. I'll release it when I've got a working prototype board and some example code.

WindowsDevPro (author)2011-06-09

I'm working on a custom replacement for the Furby "brain" (Really its main daughterboard if I can get one of the ancient LPC programs from TI, and if not I'll have to replace two daughterboards. (Main, and voice)

Message me and I'll give you my email address and website I'll be sharing everything at. I'l about to finish up a little prototype board in eagle, and then send it off to BatchPCB. And then I need to finish my video for kickstarter .... fun! :)

tinker234 (author)2011-06-06

it does look like katy perry so i guess hiting it with a butcher knfie was the wrong call whoops oh well

lloro (author)2011-06-05

It does look like Katy Perry

About This Instructable




Bio: Indie Film! Art science! Reuse and sustainability!
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