Recently, I held an workshop event for introducing

Arduino and 3D printing and most important of all –The maker culture which is sharing the enthusiasm of making things with their own hands. A couple of friends of mine and I designed a project that is easy but fun that can be finished in a couple of hours by people without learning anything in advance.(In order to make it as simple as possible we replaced many of the welding process with easier methods, it’s up to you if you want to soldier)

We called it Devil-headed Minion(you can know why we call it from it's appearance)

so let's get started !!

Step 1: Step 1: Parts List :

Electronics & Tools:

Arduino Nano w/ATmega328
LED 8x8 matrix (1088as) with MAX7219 IC board
single needle jump line caps short circuit connection blocks*2
Dupont cables (female to female)*5
3d printer and filament (approx. 40g estimated by UP Plus 2 with 0.4mm/s)
Wire stripper(any will do)

Step 2: Step 2: Wiring the Led Matrix to Arduino Nano :

1. Cut of the connectors of three dupont cables and strip of the plastic in the edges

2. Bind one of the dupont cables that had just been cut off to pin DIN on the LED matrix board

3. Bend the pin headers on the side that DIN is in and connect the other edge of the cable(with dupont connectors) to D12 on Arduino

4. Take the other two dupont cables that have been cut and bind the edges to Arduino PIN 5V and GND and cap the two pins with the jump line caps. Then, plug in the dupont connectors to corresponding PINs (the unbent side)on the led matrix board

( 5V -> VCC GND -> GND )

5. Connect the rest of the cables( CS -> D10 CLK -> D11 )

P.s Many of the steps should be done in this exact way because we need to fit it in our 3D printed main body(which is not really big)

Step 3: Step 3: Arduino Led Matrix Code

1. Download the LedControl library(if you don't know how please go to this link -> How to add libraries)

2. From testing the example provided on the library, you can find out the way to control led matrix is by sending 8 bit binary data to each row of leds

3. To create images easier I used a simulator to translate images to binary data(it is called ArduinoFrameAnimator)

4. To create an animation, it is easily done by using for loops to refresh each row(Scrolling text marquee) or just by refreshing each frame

5. I included two of my example code for my project

Step 4: Step 4: 3D Print the Parts :

There are three parts

1.The main body

2.The horns

3.The eye

(We designed it to be customizable at the
event so if you want to redesign the eye and horn here are the origin plain STL files)

Step 5: Step 5: Assembly :

1. Put the led matrix board in the main body and push the led matrix from inside of the main body to fit in the squared hole area. It should fit perfectly, if not, turn the board 180 degrees and try it again. It should look like this.

2. Slightly press the side of the bottom (which has a tiny hole) of the main body and gently insert the Arduino nano board horizontally into the body(Pin side on top). The PCB part of the led matrix board should be stuck between pins on the Arduino nano if you’ve done it correctly.

3. Continue to press the side and move the Arduino nano’s mini usb connector to the hole so that the cable can be plugged in.

4. Insert the eye into the squared hole and also insert the horns to the top of the main body

5. Plug in the usb cable and upload the Arduino code