OUR NETWORK: TechLore Explore3DTV MyOpenRouter MediaSmart home TiVoCommunity See all... About UsAdvertiseContact Us

Learn about scoring Forum's Raw Score: 1.59445E7
October 16, 2008 12:45 PM

Categories: Robot Hacks and Mods

Rating (1 votes)
  • 1
  • 2
  • 3
  • 4
  • 5
Rate This!

Member Avatar


Joined: 03/07/2008

First let me warn you, if you have small children that love Elmo with all their heart, you may not want to let them view this thread. :)

For all the help Sevik has given me while working on reverse-engineering the Elvis bust, I decided I needed to send him a thank you gift. I was originally going to send him a bust since he didn't even have one, but he isn't so much into that anyway. So I stumbled on the Elmo Live (which actually JUST hit the stores...) After showing him some videos he decided he must have one. So, I pre-ordered two of them and one will be shipped off to the Ukraine to meet its new happy owner.


But... one of them had to be opened up. And this is the story...

First of all, let's go over his movements.

Elmo Live can stand or sit, and can cross his right leg in the sitting position.

Each of his arms move up and down. His right arm also is also articulated at the elbow to allow him to bring his hand to his mouth.

His neck moves back and forth and his head can rotate upwards

Finally his mouth opens and closes

There are only 3 motors and 3 encoders to provide all of the movements. There is some trickery in how the movements are done and what must be some very interesting cams and clutches inside the two gearboxes within the torso. Obviously, I was a little disappointed about this, but it still has some potential, I think.

Unbelievably, as much as I find Elmo annoying, this toy is actually pretty entertaining (he is just a little too loud, though.) He has some cute stories, games, and animations. This generated a small amount of sympathy while I was skinning the fella.

Elmo has four switches that allow you to interact with him.

Left foot, back, belly, and his nose.

He also has a tilt switch in his left foot, which is weighted by the batteries.

While fully fur-clad, it really looks like he has a ton of articulation and his movements are very fast, springy, and life-like. The illusion is well done and all of the stories, etc... are programmed to make great use of his limited movements. Overall, a very well engineered toy that looks hard to break.

I will be "toying" around with this for a bit to see what kind of mayhem I can wrought. This thread will detail my adventures.

So far, I have managed to remove all of his fur without damaging it and will be posting the pictures and a how-to soon. I took 22 pictures just for the process of removing the fur, so it might be a little long for a forum thread.

For now, I present:

Elmo Live Dissected

Discussion:    Add a Comment | Comments 1-15 of 228 | Latest Comment | 1 2 3 416 Next »

October 16, 2008 1:18 PM

Just a warning before anyone runs out and buys this from my description above. I just got into the electronics and there are only three motors, three encoders, and some engenious mechanics. Might be very difficult to hack.

October 16, 2008 1:20 PM

That's pretty sweet, RetroPlayer. The thing that has impressed me the most about elmo live is how fast he can move (especially his mouth).


October 16, 2008 1:39 PM

Agreed. It really is what makes him seem so alive. Even if it will be tough to hack, this is some awesome engineering, programming, and animation work.

October 16, 2008 1:40 PM

Egad, it's the Elmo-nator!

October 16, 2008 1:45 PM

murmured in my best, thick, Austrian accent....

"Come with me if you want to laugh."

ScottE -- collecting and building robots for 40 years - details in profile

October 16, 2008 1:48 PM updated: October 16, 2008 1:48 PM

MrScott... HAHAHAHAHA! Thanks!

If I hack him, THAT will have to be one of his phrases.

October 16, 2008 2:45 PM

Thanks for posting this... I love how he looks skinless with his eyes kinda popping out the top :)

Looking forward to the full gallery and maybe a hack too, it sounds like!

Have fun, Pete

Peter Redmer
Blog | Twitter

October 16, 2008 8:26 PM updated: October 16, 2008 8:30 PM

RetroPlayer, After seeing the movements of Elmo Live on an ad, I was curious to see what this new Elmo looks like without the fur. Now seeing it, It looks like a good chassis for a robot. Thanks for sharing your pics.

October 16, 2008 9:32 PM updated: October 16, 2008 9:32 PM

"Come with me if you want to laugh."

Great MrScott, very funny but you beat me to it!

The cure for this disease is lack of money. It doesn't stop the itch though.

October 17, 2008 5:23 AM

I have started to do a more in-depth tear-down. As mentioned, Elmo Live consists of three motors, three encoders, 4 pushbutton switches, a tilt switch, and a main controller PCB.

There are 3 gearboxes each with a motor and a mechanical encoder. The three gearboxes are: Head, legs, and arms. The way he works is that movement through a certain range will perform one action, while moving beyond that range, it performs a different action. I started working with the head a little and will describe that. But first, let's look at some pictures:

All the main pieces of Elmo separated.

Head Mechanism

Arm Mechanism

Leg Mechanism

Main PCB top

Main PCB bottom

October 17, 2008 6:23 AM

Alright, I am going to try to explain how the head mechanism works. This might be tough to put into words. I will try to get some video after I breadboard a simple controller.

There are xxxx ranges of movement. Normal position is with the neck centered and mouth closed.

To make Elmo talk, it moves the neck forward and back with a small range very quickly.

If the neck is extended past the "talking" range, Elmo's mouth opens all the way very quickly in kind of a snap motion. It looks like he is screaming or yelling.

If the neck is extended backward beyond the normal centered position, it hits a stop and converts the movement to rotating his head upwards (looking straight up. The mouth opesn during this movement as well. Like the other way, his mouth snaps open all the way once it reaches a certain point in the motion and it looks like he is screaming, yelling, or jaw agape in awe. He uses this motion during a story about a giant where he is looking up at the giant and screaming.

Since all of these ranges open and close his mouth, he can basically "talk" in all of these positions except the most extreme where his mouth snaps open all the way. All you need to do is switch directions of the motor very quickly and move it within the desired range.

The encoders tell the CPU which range of movement the gear box is in.

October 17, 2008 6:31 AM updated: October 17, 2008 6:34 AM

I am currently looking a little closer at the electronics and found some interesting things I will be working with:

First up is the ROM daughterboard. As you can see, the connections are labeled. It should be possible to get a dump of this.

Next up is the top-side in the logic area of the board. There is an interesting jumper labeled Rx. It is connected by a trace on the board to the other side of the jumper and this goes to one of the speaker pins. The other speaker pin goes to a via directly under the CPU blob. Just a theory here, but this configuration looks like it is meant to cut the trace and use the line for serial, maybe? And then the connection could be replaced by filling the jumper.

Between the CPU and the IO Extender (educated guesses) there are two test points. If these are sunplus chips, then these test points are probably the I2C interface between the two chips. My logic analyzer should answer that question.

Also, near what appears to be an IO Extender, are four unpopulated jumpers. If filled, each one would be pulled to VSS (ground.)

The function of those jumpers are unknown. But not for long.... :)

October 17, 2008 6:37 AM

One possibility of hacking this Elmo is that it should be pretty simple to put this inside of any of the numberous stuffed hand puppets you can find at the toy stores and give it your own personality.

October 17, 2008 6:43 AM updated: October 17, 2008 6:46 AM

Anyone want to place bets on how quickly Fisher-Price contacts me after I dump the ROM and show how to make your own messages? I know this information will be used for evil.

October 17, 2008 6:43 AM updated: October 17, 2008 6:44 AM

Heh :))

I think we will have something like this weird thread if nobody will stop us early :))

Free RoboPanda!!! :)

Yes! If something has a dump, it must be hacked :))

Discussion:    Add a Comment | Back to Top | Comments 1-15 of 228 | Latest Comment | 1 2 3 416 Next »

Add Your Reply

(will not be displayed)

Email me when comments are added to this thread


Please log in or register to participate in this community!

Log In


Not a member? Sign up!

Did you forget your password?

You can also log in using OpenID.

close this window
close this window