As usual, this Halloween I decided to create a project related to the season. Using Prusa I3 and Thingiverse, I printed a Halloween decoration where the color is controlled remotely through the Blynk project.
The Blynk project lets you create a mobile or tablet app that interacts with controllers like the Arduino Uno or the Wemos D1 Mini.

Materials Needed


3D Model


#include <Adafruit_NeoPixel.h>
#include <BlynkSimpleEsp8266.h>

#define PIN D8
#define NUMPIXELS 12
#define BLYNK_PRINT Serial
Adafruit_NeoPixel pixels = Adafruit_NeoPixel(NUMPIXELS, PIN, NEO_GRB + NEO_KHZ800);

void setup()
 Blynk.begin("<BLINK_API_KEY>", "<SSID>", "<SSID_KEY>");

 int R = param[0].asInt();
 int G = param[1].asInt();
 int B = param[2].asInt();
 for(int i=0;i<NUMPIXELS;i++){
  pixels.setPixelColor(i, pixels.Color(R,G,B));;

void loop()


The first steps were to create the connections according to the scheme, implement the code and the app.
At the code level it is only necessary to indicate the token of the app (it’s sent by e-mail, or it can be consulted directly the app), what wireless network will be used and the key of this one.In the app you need to create a new project and add the zeRGBa component. In this component, it’s necessary to set the sending mode to “merge”, so that the information is sent as a single value, set the pin where the led ring is connected and set the maximum values to 255. After this alterations it’s ready to test.

Remote Color Controlled Jack-o-Lantern

Then I prepared the protoboard to receive the components. Added two rows of socket pins to be able to remove the Wemos D1 Mini for replacement or use in new projects and soldered the led ring.

Remote Color Controlled Jack-o-Lantern

Meanwhile, the Halloween decoration (Jack o Lantern) was printed on Prusa I3 in orange PLA.

Remote Color Controlled Jack-o-Lantern

The ready circuit was placed in the upper part, in order to be hidden and installed the power, being tested next.

Remote Color Controlled Jack-o-Lantern

Remote Color Controlled Jack-o-Lantern


  1. Bruno Ricardo Santos

    Gostei do projeto.
    Agora é só maximizar 300% e fazer uma gigante 😊.
    Não conhecia o Blynk!

    • Tens de maximizar mais. Aquela já está a 200%.
      O Blynk é fixe para usares o telemóvel para controlo sem te chateares muito.