Here is a great 3D printed project to under take just before Halloween. Follow the steps below, to make your self a Wearable Light Up 3D printed Jack-O-Lantern, which you can wear around you neck, or place on your work desk to get you in the Halloween spirit...

For the build you will need a 3D printer and preferably orange and transparent filament to print the pumpkin, and an Aduino based micro controller which can be used to light up a 4 neopixels/RGB leds. In my case I am using Adafruits mini trinket and a 110 mAh lipo battery to power the circuit.

Step 1: Components You Need to Complete the Build

Here is the list of electronic components you will require to complete the build

A Soldering Iron and Hot glue gun.

In addition, to 3D print the Pumpkin STL files you will need a 3D printer and filament, in my case I am using transparent, orange, black and green 1.75mm PLA. And for the 3D printer, I am using a Flashforge creator pro , which has a pause and un-pause option, which allows me to switch filament in the middle of the print.

Step 2: 3D Printing

Download the STL files attached and using 3D printing software slice, and 3D print the files.If you don't have a 3D printer handy you can use one at your local maker club, or library, or use a 3D printing service like 3D hubs.

In my case, I printed the STL files using the Flashforge creator pro and 1.75 mm PLA,and for slicing I am using Slic3r with the layer height set to 0.3mm and infill density to 60 %.

To print the PumpkinTop.stl file, I started of with transparent filament, and then switched to Orange PLA as soon as eyes and the mouth began to show, followed by the black at about 82% of when the print was about to complete, and then green when 92% of the print..

Step 3: Circuit

For the circuit I soldered 4 neopixel in a chain, keep a close eye on the direction arrow for the Data in. And connected the

+ve of the first neopixel to Bat+ pin on the trinket
GND on the neopixel to GND of the trinket
and the Din which is marked by the arrow to the pin#1 on the trinket.

And at the other end of the neopixel I connect a female connector for the Lipo, so that it is easy to mount in the 3D printed parts.

In addition, I connected a slide switch to the +ve side of the lipo, so that is easy to switch the power on/off to the trinket.

Step 4: Uploading Arduino Sketch

Install Arduino IDE on your computer, and go to preference in the Arduino IDE, and add the URL below in the additional Boards Manager URLs

<a href="https://adafruit.github.io/arduino-board-index/package_adafruit_index.json">https://adafruit.github.io/arduino-board-index/pac...</a><br>

And then search and install the Adafruit AVR boards package, once do you will see 'Adafruit Trinket 8MHz' under Tools -> Boards, as you see in the picture above.

Now download the sketch attached, select the port, press the button on the trinket and upload the code. For more info on Arduino IDE setup/driver install for you computer, check out the learning guide at - https://learn.adafruit.com/adafruit-arduino-ide-se...

As part of the sketch, I have the two pixels in the middle glowing red, and blinking every 1 second. And the green for the eyes of the pumpkin glow continuously. Modify and upload the sketch with the colours you prefer , try the eyes with as blue colour instead of green.

For more info on the Trinket check out the learning guide at - https://learn.adafruit.com/introducing-trinket?vie...

pumkinNeoPixelSimple.ino
Download

Step 5: Putting It All Together

To add the electronics components to the 3D printed parts I used hot glue, start by hot glue'ing the Adafruit trinket on the pumpkin 3D printed part on the side of the pumpkin that does not have the semi circle in the eye, so that it lines up with the opening of the base, so that you can reprogram the trinket if you dont like the colours.

Add the switch to open of the top openings of the base and the lipo in the centre of the base towards the right of the hole in the base so that opposite to the trinket.

Once you run the test you can hot glue the top to the bottom 3D printed parts. and to recharge the lipo remove the battery JST pin and connect to the Lipo charger..