LED Emoji

Hello in this instructable i will make a glowing emoji with LED strip and 3D printed housing. The concept is rally simple you have a LED strip that tuns in whenever emoji is poked. It is perfect for decoration in kids bedroom or just for adding something next to your bed on night shell. Emoji is pretty simple to make it take ruffly 5h including printing and soldering. I will show you step by step how I tested and put everything together at the and.

ARDUINO UNO
ATtiny
LM7805 Voltage regulator
circuit board
2n2222 transistor
9V battery
wire

I made 9V battery holder from old 9V batery

Of course you will need some basic tools like soledring iron, pliers, hot glue, knife and markers. Another thing that you need is a 3D printer, if you don't own a 3D printer you can order online or contact Robosap for printing service.

First I had problem witch microcontroller should I use, Arduino uno, nano, pro mico any fo those would bi toatal waste and overkill for this project. So I took Attiny85 which has 5 IO pins VCC, RST and GND. This was perfect for my project. But you can't just stick Attiny at Arduino uno and start programing even ardoino IDE does not support this microcontroller. In next steps i will show you how to download Attiny bord info.

Here you can see step by step how I downloaded and instaled arduino software plus attiny board data.

ARDUINO IDE: https://www.arduino.cc/en/Main/OldSoftwareReleases

Arduino UNO ATtiny

PIN13 -----------------> IO2
PIN12 -----------------> IO1
PIN11 -----------------> IO0
PIN10 -----------------> RST
5V -----------------> VCC
GND -----------------> GND

Don't forget to put 10uF capacitor between RST and GND on arduino.

First you have to flash Arduino Uno as a programator with includes ISP example. Then I write simple blink code just to test if everything works. I conected LED to pin 3 of attiny with 470 ohm resistor in serial.

Here is the circuit diagram and all necessary parts links. I will create another smaller version of circuit in the near future so stay tuned. I added a resistor in serial because I did not have LM7805 at home.

NOTE: Button in circuit is optional in my case I did't use it but you can add button and place diferent animations.

I designed emoji in fusion 360 and printed on anet a8 with white PLA and some upgrades. of course you can make any style of emoji. I pasted two examples.

One you have painted the emoji is time to add an LED strip. LED strip might not fit perfectly in your first try so just band it a little and use some hot glue to hold everything in place

NOTE: Solder all the necessary wires first it will make your life easier.

When you have soldered everything together it's time to add previously made circuit with ATtiny85.

I wrote some simple code in arduino IDE just to test if everything works as it should. But you can experiment as much as you want. To load the code take a look at previous steps and how it is done.

When everything works awesome is time to put everything together with some hot glue and make it permanent. Now you can hot glue pcb board to back of the emoji.

This project was very interesting and adjucational for me. I definitely learned a lot about ATTINY and how powerful actually this microcontroller is. I spent some time in fusion360 and Cura slicer. This was my first print with 3D printer and i must say that I am impressed how Anet a8 handled this print, I must recommend this printer to everyone who wants to buy a 3D priner.