Arduino animatronics- make your awesome costumes more awesome!

Here's how to add lights, sound and action to your favorite Halloween project using the open source Arduino microcontroller. Arduino is easy to learn to use and it opens up a whole new world for costume builders and creature creators. If you want to learn how to connect wires, servos, LEDs and use sound effects to add that something special to your latest project then this is for you.

I'll show you how to make a neat little compact Arduino servo controller board with built in servo connectors that is perfect for costuming and haunted house applications. There are multiple code examples, wiring diagrams and I'll show you how to connect sensors and even how to connect two controllers using wireless radios.

Here's a little movie clip of what is easily possible- an animatronic Predator cannon with laser sight, cannon firing sound and head tracking motion control.




Here's an Iron Man hand repulsor with servo to open the forearm missile compartment. Follow along and find out how to make your awesome costumes more awesome...
 

Update: My instructable for showing how to make an animatronic Stargate helmet is here-
http://www.instructables.com/id/Animatronic-Stargate-helmet/

Note- While this instructable is written for the beginner, this tutorial assumes you know how to use a soldering iron and other assorted tools like wire strippers and wire cutters. Please be sure to take proper safety precautions, wear safety glasses when using cutting tools and have adequate ventilation when soldering. If you aren't yet comfortable soldering small surface mount components don't fret- I've posted links in the reference section that will help you become a soldering champ in no time.

Step 1 First you need an Arduino

Arduino? What exactly is Arduino?

Arduino is an open source microcontroller- essentially it is a small computer with an easy to use cross platform programming language. It allows you to create interactive objects based on sensory inputs (physical computing.) You can use it to do something simple like make an LED fade or have a servo move when you push a button or have it do something very complex like control a robot by processing sensor inputs, send the inputs to a computer over a wireless network and then send commands back to the robot. The applications are really limited only by your imagination and there are thousands of examples of cool projects all over the Web. There are several books about Arduino and its capabilities and I've listed a few in the reference section.

Which Arduino to use?

There are several variations of the Arduino controller available so which one do you use? It depends on your application. Some have more input pins than others if you need a lot of sensor inputs. For the purposes of this instructable you really can use any Arduino you like as the information presented applies to most every version. Here is a spreadsheet that shows most of the current variations available-
https://spreadsheets.google.com/ccc?key=0AsCUiP6WbJIvcG8xalA3QVdmb3JVT0ptWE9VNC02WEE&hl=en#gid=0

If you are going to use an Arduino Uno or Mega or any Arduino that has built in USB then you can skip to the getting started section.
 

Building a servo board

Since my focus is mainly on costume building I decided to use the Sparkfun Arduino Pro Mini and then build a compact servo application board for it that has multiple servo outputs, analog inputs and digital outputs. I also added a socket for an Adafruit Xbee wireless radio adapter as well as a charging circuit for a single cell LiPo battery to power the controller.

The reasons I really like the Pro Mini are its very small form factor, low cost and low power requirements. It operates on 3.3V, which means it can be powered by a single LiPo cell and that makes it easy when connecting sensors that run on 3.3V.

The latest version servo board has eight servo outputs, four digital outputs and six analog inputs. The servo outputs are also digital outputs- they're just configured to make it really easy to connect hobby servos. The earlier version seen in the photos has six servo outputs. Each servo output has three pins- ground, power and signal. The analog inputs are configured the same way- each input has three pins- ground, power and signal. This configuration makes it super easy to connect individual sensors. The board measures 1.75" x 2.30" so it's pretty small.
 

The board has a circuit for charging the LiPo cell that powers the controller. There is a mini USB port for 5v input power. Simply connect the battery and then plug in a USB cable and the battery will automatically charge. There is a charging indicator- the LED is on when the battery is charging and then it will automatically turn off when the battery is fully charged.
 

The mini USB port will also power the controller, even without a battery connected. The mini USB port is only used as a power source connector while charging or during times when a LiPo battery is not available- there is no data transmission using the mini USB port and you are limited by the amount of power a USB port can provide.
 

Code is uploaded to the controller using a USB to serial adapter (more on this later.) This adapter can also power the controller over USB without the need to connect the battery. This comes in really handy when you're testing code and you want to power the controller without having to connect the LiPo battery.

I'm providing all the necessary EAGLE files so people can modify the design to suit their own needs.

EAGLE can be downloaded here- http://www.cadsoftusa.com/

Comments

[ConcordStud733]

Hey there Honus.
I was just wondering, im getting into micro controllers now I know how to solder but my main goal is to just have a couple flex sensors control a couple servos and possibly integrate an lcd screen in at some point in time. Is the controller and mini you have in this instructable able to use an lcd?
and if I just bought an Uno, would I need a controller board and circuit like you built or would I just be able to hook the flex sensors and servos straight to the unoo?
I hope u can help me out I've searched for a few days to answr these questions and haven't found an answer. Thanks alot for ur help

[Honus]

You can add an LCD screen to any Arduino- have a look here:
http://www.ladyada.net/learn/lcd/charlcd.html

You don't necessarily need a controller board (or shield) but it makes hooking up sensors and servos a lot easier. You can also use a breadboard if you just want to plug stuff in and try it out and that's what I would recommend if you're just starting out. If you look at the examples you can see diagrams how to hook up a servo and flex sensor directly to the Arduino using a breadboard.

Hope this helps- let me know if you have any other questions!

[ConcordStud733]

Thanks alot for help.

Did you actually make a forearm missle compartment? Im trying to figure out how I can make an arm mount without buying an expensive medical bracee and not out of paper lol

[Honus]

No I haven't made the compartment yet but it's a pretty simple mechanism. For an idea as to how to make one have a look here-
http://www.siwdat.com/forum/viewtopic.php?f=227&t=208

[thepred2012]

Would you be willing to do another one and sell it? I am no electrical genius, even the code confused me...I am trying to put a good predator outfit together for 2014 Comicon. Any help is appreciated. You are truely gifted!

[Honus]

Once my friend gets the backpack and cannon finished kits will be offered. No idea on pricing yet but hopefully soon.

[c_Dub1082]

First I want to say I love your project. I have been wanting to do something similar for a very long time. Love the movie as well. I am currently doing the project for my senior project and things are going ok. We are haveing some issues with the x-axis on the accelerometer. It seems that in order to pan the x-axis we have to do a barrel role with the accelerometer. We tried all kinds of orientations but it will not work any other way. Any suggestions??

[c_Dub1082]

Thanks man, we finally got the orientation right. You were right that it takes a little getting used to. We appreciate it.

[Honus]

Cool- if you have any other questions just let me know!

[Honus]

Accelerometers only work with respect to gravity so that is why it works the way it does. There is further explanation in the FAQ section.

[cpaternoster]

do you sell this mechanism? i dont understand if you control it or if it has a motion sensor. Thansk, its awesome

[Honus]

Not yet- I'm waiting for the complete backpack to be finished. The person wearing the costume controls it. You have two fingertip buttons- one activates the cannon and the other "fires" it. When the cannon is activated it raises into the firing position and tracks your head movements.

[uj_boy]

Hi There Honus,

Apologies for potentially silly question - i'm very new to this!

I'm looking at building the War Machine Cannon; I have an Arduino UNO (but have no need for the sound, so don't have adafruit). I also have the Pan/Tilt you suggested (powered by the 2 Servos motors). Looking At your diagram, will i need an Arduino Mini Pro Also? Or can i just use the UNO? i must admit, i'm a bit confused :s.

Thanks!

Andy

[Honus]

Sorry- I should clarify that- you use the Arduino UNO in place of the Pro Mini board.

[Honus]

You can just use the UNO if all you want is the pan/tilt.

[jackjackattack]

how long did it take to build the cannon?

[Honus]

If you mean just the cannon resin casting my friend makes them. As far as the cannon arm design goes I'm in the middle of redesigning it right now.

[the cage]

Hi Honus.
First of all: Your work is absolutly great!
I'm working on a Iron Man arcreactor + 1 lower arm with hand repulsor, like seen in one scene of the first movie. in the beginnings I experimentated with some low budget solution: Soundmoduls of greetingcards. Perhaps a tip for people with very low budget. But i want to synchron the lighteffects with the sound, so your instructable is perfect for me.
My first question:
Is it right, that you need an Arduino uno under the wave shield? Is there nothing to programm onto this Arduino?
Second question:
Can i put 2 different sounds on the waveshield, wiche are played with different input pins high?
Third question:
Why do you power the two arduinos with two 9V Blocks?
My planed setup: 2 x Arduino uno, 1x wave shield , 2 bend senors, two led circuits (open the hand -> repulsor starts glowing; spread thumb away from forefinger -> second led circuit with blast sound), powered by 9v blocks + step down voltage regulator.
Thanks again for your awsome instructable!
Felix

[Honus]

Thanks! Yes, the Wave shield fits on top of an Arduino Uno. You program the Uno to play the sound files. There is a link to the code used that will allow you to play six different sound files. The diagram just shows 9V power to both Arduinos- it's doesn't have to be two separate batteries.

[the cage]

Oh sorry, missed that...
I just looked a little bit closer into the programming. With another if condition in the first one, it should be possible to use one bend sensor as tricker with two threshold, right? open hand -> threshold 1 -> glowing repulsor, finger straight -> threshold 2 -> blast effects.
By the way, I changed the power setup: I will use 3V batteries for the LED instead of the step down regulator. If theres no energy for the Arduinos left, there will be still energy for the LED's of the Arcreactor.
Thanks again for your instructable. Without your great instruction, I would never start the project with Arduinos. But the potential of the Arduinos is just huge!

[Honus]

Yep- you just set individual threshold limits for the two different bend sensors and treat them as two separate inputs. Make sure to post your project when it's done!

[the cage]

Hi Honus,
i have a problem: Have to finish the project today. but I forgot to buy the 1k Ohm resistors infront of the tip120, and i won't get them here. What are they for? Are they just protecting the transistors? Would it work withou them?

[Honus]

Those resistors protect the Arduino output pins- without them you could fry your Arduino. I wouldn't hook up the transistors without them.

[the cage]

found 2 until now in my dvd player. One to go for the second led ciruit. But to much smd everywhere ;-)

[the cage]

Hi Honus!
Thanks for your fast repley yesterday! Saddly, I didn't made it: Found a third 1k resistor in the dvd player (broken by the way): a 102 SMD. But it was so tiny that it always broke before I was able to coat it with epoxy.... No chance without a board, just soldering the wiring. So I went to bed, had a good sleep and a good idea to optimize your circuit:
I read that the wave shield doesn't use the analog input pins, and that they could be used as output, too. So what i will try next: Just one arduino uno with waveshield, one flexsenor with two triger values (trigerglow & trigerblast) on Analog 0, the blue "Glow" Led circuit ond A1, and the white "Blast" Led Circuit on A2. Should work i gues, and i need just one arduine and, very important, 2 1k resistor on the transistors ;).
Heres a picture of my selfmade repulsor board, I made with my laserjet and "Natriumpersulfat". Quite good for the first try :)

[the cage]

Having another problem :(. i connected the led with tip120's (everything without the waveshield). but the leds are not nearly as bright as connected directly to the power source. how could that be? I think it's even brighter if i connect them directly to the arduino! Are there different TIP120's or are they all the same?

[Honus]

The PCB looks great! As far as I know all TIP 120s are the same. What LEDs/resistor values are you using?

[the cage]

The LED's are 3,2V SMD LED's:
http://www.conrad.de/ce/de/product/180958/LED-SMD-PLCC2-BLAU-DDB-UJS-RS1-1/SHOP_AREA_17320
and
http://www.conrad.de/ce/de/product/180966/LED-SMD-PLCC2-WEISS-DDW-PJG-WX1-1/SHOP_AREA_17320
with 100 Ohm resistors.
If i measure the voltage between Emittor and Collector i just get about 0,9 V! That's not okay, isn't it?

[the cage]

Wait, at the transistor shouldn't be any V... measuring my board, theres just 2,1 from the 3 v battery.

[Honus]

Are you sure you have the transistors wired correctly so that when the Arduino output pin is high the transistor turns on? What is the voltage at the LED when the transistor is on?

[the cage]

Transistor Base with 1k Ohm to the arduino output pin., Collector to the PCB, Emittor to - of the Battery.
If the transistor is on, i just get the 2,1V at the led. I'm loosing the 0,9V somewhere in the transistor?!?

[the cage]

and emittor to the ground....

[Honus]

Are all grounds connected together and the LED has it's own power supply?

[the cage]

All grounds are connected and the led has a own 3 V power supply. If the transistor is on i have 2,1V at the LED and 0,9 V at the transistor between E and C. If i bridge E & C at the transistor, I have 3 V at the LED, but logically the transitor is out of function... this thing is killing me!

[Honus]

Here's what's going on- TIP 120s will have a voltage drop and that is what is affecting the brightness. The LEDs I used were rated at around 4V and I used a single cell LiPo battery, which is rated at 3.7V but actually measures just over 4V on a full charge. That's why I never had any brightness issues. Try using 3 AA rechargeable batteries that are rated at 1.2V each and see what that does to your output voltage at the LEDs.

[the cage]

Thanks, that's what I thought, too. The Datasheet of the TIP 120s says something about 60V. A drop of 0,something V wouldn't count there, but at 3V...! I just tried the complete setup as planed, but without the transistors: getting the led power from the arduino. I don't know why, but with the waveshield on A2 and A3 i get enough power for the full brightness. Wasn't the case at my first try with the naked arduino. But looks quit cool now, hehe. I didn't want to use another powersupply, because i have allready the 3 V for the arcreactor, and the 9 V for the arduino in my pocket. Another advantage is, that I don't have to wire the Arcreactor with the repulsor arm, so I'm quite happy with it.
Now I'm in the programming stuff. With some testsounds its working fine:
1. Open hand-> trigger 1 -> blue led circuit high and start up sound
2. hand still opend -> blue led circuit high and a electronic waving loop sound
3. complet open hand -> blue and white led circuit high and a looping blast sound
4. closing hand a bit -> white led circuit of and Modus 3
5.closing hand completly -> everything off.

Now i will ad some dimming effects. That for, I have to look over the playing procedure, because I took the playcomplete, which causes, that the arduino will do nothing until the sound is completly played. But not a big problem i think.
the glove is waiting for the electronic components to be glued together and the arm waits for its production. Looks quite good at the moment. I will post some images when its done.
Big thanks for your help!
Regards, Felix

[Honus]

Felix,

Cool- glad everything worked out. Make sure to post a video!

[nobodysktr]

Doing an Irongman build and plan on having quite a few animatronics/lights etc. Do you think i could run the electronics for the eye lights, faceplate movement, and maybe voice changer on one controller or would I need a few?

[Honus]

You could easily run all your lights and movements from one controller. Having sound effects would require a separate sound board.

[nog3]

Hi Honus,

I'm a relative newbie to Arduino here and thought this tutorial was very helpful.

I'm just curious if you've contemplated using either the Arduino Stamp or the Seeeduino Film for animatronic projects?

I've got a very space sensitive project (Animatronic enlarged fist) which will mostly be consumed by the control glove, servo and mechanics and the Film looks perfect for this.