A couple weeks ago Charles sent me a link to a video from a company that makes a bunch of animatronic products. They’ve got a remote-controlled bird puppet that moves its beak and turns its head side-to-side. It sells for… NINE HUNDRED DOLLARS!? And that’s their cheapest product. I suggested that maybe, if you weren’t that interested in the wireless aspect of it, it might be possible to do something a bit cheaper. Like, oh, $800 cheaper…
My first thought was to use a nunchuk from a Nintendo Wii. It’s cheap and interfaces to an Arduino microcontroller fairly easily. I did a bit of poking around and worked out that a single Arduino can control up to 8 servo motors. I figured I could control one servo per button, and one for each joystick axis.
That would use up 4 servos, leaving 4 free. I decided to add an audio jack to see if I could drive a servo based on recorded vocals. That would use up 2 of the remaining ones; one for each audio channel.
I wired up a protoboard with connectors for a nunchuk, 8 servos, an audio input and a power supply for the servos.
…and wrote some code to read the inputs and translate them into servo data.
Here’s a test with a nunchuk driving 4 servos.
To test it out in a practical situation, I built a puppet stand out of PVC pipe and strapped the electronics to it. Here’s the result.
I’m only using one servo there but you could conceivably use a bunch on a single puppet, say, to move the head side-to-side or make the eyes blink. Maybe even assign a sequence of movements to a single button press.
Oh, and the total cost of the rig shown in the video?
- Arduino – $30
- nunchuck – $15
- servo – $12
- connectors & components – $10
- PVC pipe – $10
- 9V supply – $7
- protoboard – $6
- 6V battery pack – $2
So, $92. You could even throw in another servo for moving the head and still come in just over $100. Add some felt and foam, and you could make a whole flock of birds for $900.
Back when I used to sell puppets, I happened to be wearing a very realistic dog puppet while hanging out by the door to the store. Two women spotted me from about 40 feet away and came running over. This happened often, because the dog looked so real.
They ran up to me and were surprised to find that it wasn’t real. One woman said that her son would love it and asked me how much it was. I said it was $40. She was surprised that it was so inexpensive, which surprised me because usually it was tough to sell a $40 puppet for children. We went inside to ring her up and she asked how many batteries it took. I told her none and showed her how to hold it so that it looked real. She huffed and said she had no interest in buying her kid something he’d have to work to operate.
That is all.
Fake robot dogs are the worst.
I think I said it on Twitter: Wil Wheaton may be able to throw out a comment to the internet and somebody will make it, but we can put a bug in Steve’s ear and “boom” results!
This has some great potential once I get more eye blink/move manipulation worked into some designs.
If not for the sound, I wouldn’t be able to tell the difference between that “robo puppet” and a normal one that you can controlled with your hand.
Rebecca’s story depresses me for reasons that I can’t quite identify.