"Skilled Chimp" - Halloween Arduino Project

Do you want to spook up your house for Halloween using an Arduino, some LEDs ands cardboard? Look no further! With this project, you can create a rather creepy-looking sign that turns from a rather inoffensive "SKILLED CHIMP" to "KILL HIM" once you get close enough. By modifying some of the internals, you could get it to say other random things such as "ILL CHIMP", "LED IMP" and many more!

Electronic Components:

• Arduino UNO Board. By adapting the code, you can make it work on other boards too, but UNO is the most used and you can repurpose it for many other projects!
• USB Cable to program the Arduino UNO
• Breadboard
• Breadboard Jumper Wires
• Red LEDs (in our project we used 6, but the more you add the brighter it will appear!)
• 1 resistor for every LED used
• HC-SR04 Ultrasonic Sensor (alternatively, you can also use a button although how that would function is not explained in the Instructable)

Note: you can buy a kit that has all of these electronic components (Amazon) or buy them at your local shop.

Materials:

• Cardboard (regular packaging cardboard for a quick model or grey cardboard for a sturdier model. We used grey cardboard in our own).
• Tape
• Glue

Tools:

• Laser cutting machine (or alternatively pencil, ruler and a cutter)
• Computer to program the Arduino (with Arduino installed)

The green lines show female to male breadboard jumpers and the black lines show male to male breadboard jumpers.

For the whole thing to work without making any changes to the code, this is how you need to wire it. Note that as long as you have the pins in the right numbers, you can place the resistors and the LEDs differently on the breadboard. Of course, bearing in mind how the connections in a breadboard function. We have placed them this way simply for clarity purposes.

As it's a little hard to see, the HC-SR04 is wired the following way:

• Vcc goes to the power line in the breadboard (any slot along the top red strip).
• Trig (short for Trigger) goes to pin 12.
• Echo goes to pin 13
• GND (short for Groud) goes to the ground slot in the Arduino (or to any slot in the bottom blue strip of the breadboard).

You can solder the wires for extra safety, but we've used regular Breadboard Jumper Wires and it works prefectly fine.

Of course, you can change pins around as long as you also change them on the code (below).

You will need to power the Arduino board at all times (we recommend using the same computer used for loading the code into the Arduino for powering it during use).

Very important! For the program to work, you must do the two following things:

1. Download the Arduino file attached and place it within a folder with the same name as the file.
2. Install the library "HC-SR04" by Dirk Sarodnick. To do so, head to Sketch - Include Library - Manage Libraries in the Arduino program, search for it on the seach bar and install it.

Use the Arduino USB Cable to upload the code to the board you've built in the previous step and check that it works as expected.

As stated before, there are two main ways you can do this: using a laser cutting machine or by doing it manually. If you are using a laser cutting machine (what we did), we recommend grey cardboard as it is thinner and sturdier than packaging cardboard. If you are doing it manually, cutting grey cardboard is likely to be a pain, so we'd recommend packaging cardboard.

We have attached a .dwg file that you can use to cut the pieces needed and SolidWorks Part files for all the neede pieces. Nonetheless, the measurements are the following:

• A: 1x 700x150mm with the "Skilled Chimp" letters.
• B: 2x 155x50mm. These pieces are used for the sides.
• C: 2x 150x47.5mm. These pieces are used to isolate the letters "S" and "P" from either end of the words.
• D: 2x 150x72.5mm. These pieces are used on either end of the central "ED C" section (i.e. "KILL" | "ED C" | "HIM")
• E: 2x 700x150mm with 250x25 and 250x24mm cuts on two corners to form a "podium" shape. These are used for the base and the upper cover.
• F: 1x 252.5x155mm. This piece is the back cover of the letters "HIMP".
• G: 1x 242.5x155mm. This piece is a back cover of the letters "SKILL".
• H: 1x 210x155mm. This piece is the back cover of the letters "ED C".

Recommendation: build the whole structure (A-E) using glue and leave F-H open to install the electronics and only attach it using tape.

And once you have wired the whole thing and put it inside the box, you only need to poke a hole through the back for the cable to the computer to be attached and start spooking everyone that comes into your house!

This project was done by Yana Kuznetsova, Pau Padrós and Eirene Zhen Pérez.