Robot for halloween and more


I am interested to make a simple 4ft tall animatronic figure for Halloween, and then continuously develop it further with more capabilities. It will be outside my house in the dark on Halloween night.

I am fairly new to arduino and electronics but have a mech. eng. degree and have build rc things before.

I have been doing research over the past few weeks and doing many tutorials from the Uno starter kit and others online including Bluetooth coms.

So I've sort of figured out that I need to know everything about all the components to do it right even for basic functions, and I'm very pressed for time because Halloween is in 10 days and I don't have much yet. Electronic suppliers and distributors such as Digikey have been helpful.

I am looking for some help to expedite a simple robot for Halloween if you can recommend anything to me regarding the components that would work together it would be greatly appreciated.

What I would like to do is:

  1. Lighting: Figure is hollow plastic construction and lit from the inside by leds. I think I need about 2X 100 lm or 5w rgb leds. I want to control the brightness and color to whatever program I write. One effect I'd like is a rapid bright white strobe light.

  2. Sound: I would like the figure to emit a variety of sounds, some very loud, depending on the control program and sensor inputs. I think it needs to be as loud as a loud alarm clock. I would like to supply a large variety of MP3 sound files to play depending on conditions. However could get by with several short clips.

  3. Motion: I originally wanted this to be a mobile, rc controlled robot/figure, but I think that feature will have to wait due to development time and cost. So, the figure has a head, and at a minimum I'd like the head to rotate to positions determined by the control program. It's light-weight maybe 1 lb, I might have a motor for it already, I don't know the voltage it's pretty weak but has a gearbox. I could also use a medium servo I think if I could control the speed of rotation (slower). Ideally, I would have sound and motion detection and it would turn it's head to look at passersby.

  4. Control: One feature I really want to implement is a reaction to an event, the event being when a certain object is briefly brought near or physically impacts the figure, I want the figure to react with light and sound effects and possibly motion. But I want it to react only when this particular object is near (has made contact) with the figure in any location. So I think the object has to have some small device in it that is detected by proximity, or maybe a shock sensor in the figure that detects contact. This feature is an important one.

  5. Logistics: What I'm shooting for is the simplest way to implement as many of these features as possible before 10/30/15 and at reasonable (low) cost. Because it's my first time doing this I am really hopeful that someone may offer some guidance or recommendations for some simple I/O hardware systems I can implement easily. Then I will refine it greatly in the future, and report results!

Basically I need to select leds, power supply/control/sensors/shields/motors/speakers/amplifiers to do the things listed as quickly simply and easily as possible.

If anyone has had success implementing some similar features and capabilities and is willing to share I'd greatly appreciate it. Sorry for the short notice! I just need something that will work at a minimum now and I'll improve it later!

Thanks. Stephen

No takers ??

I know there is a lot of knowledge out there! :)

Recommendations for driving high-power 500mA (5w) leds?

A good way to drive a small stepper motor, and 2 "260" drive motors?

How about a good way to set up a MP3 playing sound system, board, speaker and amp?

A good way to set up detection of proximity between 2 objects and detecting impact shock vibration?


You have set a very unrealistic timeframe. If today was the 23rd of September I would still worry that I could not get half of that done.

For the LEDs, get the strips that have controllers built into them WS-something-or-other. You can give them commands from the Arduino very easily.

For motors, the Adafruit motor shield is good. It's not ideal for driving steppers but it can do a good-enough job.

MP3 Yes, you have some good ideas there.

Proximity between two specific objects? Not just a motion detector that detects 'anything' in front of it? That's a tricky one. There's a couple of ongoing threads in Programming Questions at the moment trying to solve that one.

Shock, vibration yes. What did you have in mind?

No takers ??

Your project is large complex, and somewhat vague. Probably best you use google to find Halloween projects others have made and duplicate those efforts. I think I remember the below eyes being developed a long time ago. Big glowing spooky eyes with eyelids might be a a doable project.


First thanks for replying. Here are more specifics:


  1. waitfunction() controls system outputs while waiting for inputs. Will call headmotion(), bodymove(), lights(), and sounds().
  2. headmotion() to control head rotation.
  3. bodymove() to control robot translation.
  4. lights() to control LED lights.
  5. sounds() to play mp3 files.
  6. shocksensor() to monitor shock sensor for activation.
  7. humansensor() to monitor human sensor for activation.


  1. Run waitfunction() routine until either input is activated.
  2. If shocksensor() activated, call shockfunction(), which sends a series of commands to the output for a period of time. Humansensor() is ignored whie running.
  3. If humansensor() activated, call humanfunction(), which which sends a series of commands to the output for a period of time or until the human is no longer detected. Shocksensor() can be activated while this runs, and will stop the humansensor() routine and run shockfunction() instead.


  1. "Shock Sensor" When the robot plastic skin (1/16" Makrolon polycarbonate) is impacted over a certain threshold I want the controller to respond by running a function that will varying the outputs, and ignore further inputs until the "shock detected" output function is complete. I have the piezo that came with the uno starter kit for use with the "knock lock" program I thought I would try that affixed to the robot skin, if not try an accelerometer, what do you think is the easiest approach?

  2. "Human Detector" I got a Parallax 555-28027-RT PIR motion sensor _rev_b (passive infrared) which outputs a high or low digital output on one pin. I want to run different routines (functions?) depending on the activation of the sensor.


Motion: 1. "Body Translation": I want the robot to move back and forth via a small tank chassis that has two 3V Mabuchi RE-260 motors in it. I think I would apply a selected voltage/current for about 10 seconds in each direction and repeat until one of the sensors is activated. From the data sheet each motor has maximum ratings of 2.7 amps stall 350mA full load and 5 volts, but I probably won't actuate it at the highest speed. I have the Arduino brand motor shield but I don't know if it will handle it. Working on that tonight. When the shock input is detected I want to run a different motor routine, vary the actuation direction and duration, simple commands.

  1. "Head Rotation": I want the robot head to turn back and forth, slowly, between random positions in a certain range, I have already implemented this by setting the angle and it works with a std. micro servo. I think I need a medium size one though, and need to control the servo speed because it rotates too fast when just commanding positions. I am trying to write code to actuate the servo as an arbitrary function of time right now (ie. position = sin(wt)) or something. When the Human Detector sensor is activated I want the servo to turn to a preset location. When the shock sensor is activated I want the servo to run a different position routine.

Lights: 1. "Internal LED Lighting:" I think I need about 2 x 3w RGBW LEDs that output 100-200 lm each They are 350mA LEDs that run up to 3.4V. I found some online and multi-channel current controllers I wonder if I can do it with some MOSFETS if that would be cheaper or easier or simpler, recommendations? I want to control the light brightness and color to any arbitrary setting based on the inputs and controls.

  1. OPTIONAL "Strobe light:" I found a mini fast-firing strobe light I thought I could use, to activate at certain points in the program depending on the inputs.

Sound: 1. I want to get an "mp3 board" that will output sound to a speaker on the robot, and play selected sound files depending on conditions. I haven't figured out yet which boards to get. I am looking for something cheap and reliable and easy to implement. I want to get ~90dB sound at 1 meter, I think about a 5w speaker would work good. This part I am less clear on, I have found mp3 playing sound boards but I don't understand what their output is, they don't have headphone jacks or other audio connectors, so how do I use the output from them? I would like to output the sound directly to a powered speaker if possible with a headphone-type jack. Or should I use an amp:

So these are some of the things I'm interested in and some I've found, just looking for input on things to serve these functions easily that will work well together. I am most concerned about the code structure and handling the inputs as that seems like it could be tricky. What do you think?

Thanks for your suggestions so far, I am just looking into them because I have so much to do.

BTW how do you post an active web page link??

Thanks! Stephen

Looks like you are making good progress.

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