Published May 1, 2026

Chicago UV Tracker

Physical representation of Chicago's UV using a diorama of a Chicago beach

BeginnerShowcase (no instructions)2 hours3

Things used in this project

Hardware components

SparkFun Snappable Protoboard

Jumper wires (generic)

Digilent Stepper Motor

Adafruit NeoPixel Digital RGB LED Strip 144 LED, 1m White

Particle Photon 2

Software apps and online services

Particle Build Web IDE

Story

The purpose of this project was the create a visualization of the UV levels in Chicago. I made this as part of an in-class assignment that is about visualizing data from online.

Project from front

For this project, I pulled data from an online UV API using the coordinates of Chicago to get me accurate UV levels. I then coded an LED strip that is hidden behind the yellow sun in the top left corner so that the brightness of the LEDs is dependent on the UV outside. The umbrella seen on the righthand side originally spun every time data was pulled (every 30 minutes), but for testing purposes it is currently spinning constantly at max speed.

Back of project

In the top right, a piece of cardboard was taped behind the sun in order to keep the LEDs in place behind the sun. In the bottom left is a compartment under the sandy box seen in the first image, in which I placed the protoboard and and motor so that the motor can spin the umbrella from underneath.

Close up of compartment

The motor was mounted onto a stand made of clay so that it is tall enough to reach the umbrella.

Code for project

// This #include statement was automatically added by the Particle IDE.
#include <neopixel.h>

// This #include statement was automatically added by the Particle IDE.
#include <Stepper.h>

// This #include statement was automatically added by the Particle IDE.
#include <ArduinoJson.h>

// Include Particle Device OS APIs
#include "Particle.h"


const int stepsPerRevolution = 2048;
int stepperSpeed = 15;
//See if you can make a float
int brightness = 0;

#define IN1 3
#define IN2 4
#define IN3 5
#define IN4 6
Stepper myStepper(stepsPerRevolution, IN1, IN3 , IN2, IN4);


JsonDocument doc;

#if (PLATFORM_ID == 32)
    #define PIXEL_PIN SPI1
    #else // 
    #define PIXEL_PIN D2
    #endif
    #define PIXEL_COUNT 20
    #define PIXEL_TYPE WS2812B
    
    Adafruit_NeoPixel strip(PIXEL_COUNT, PIXEL_PIN, PIXEL_TYPE);
    



void setup() {
    Serial.begin(9600);
    
    while(Particle.disconnected()) ;
    
    Particle.subscribe("hook-response/UVPULL/0", extractInfo);
    delay(1000);
    
    Serial.println("Particle connected to cloud!");
    
    
    Particle.publish("UVPULL");
    Serial.println("PULLED");
    
    myStepper.setSpeed(stepperSpeed);
    
    strip.begin();
    strip.show();

    
}





int lastPublish = 0;

void loop() {
  
   
    strip.setBrightness(brightness);
    myStepper.setSpeed(stepperSpeed);
  
     for (int i = 0; i < 20; i++)
        {
            strip.setPixelColor(i, 255, 180, 0);
            strip.show();
        }
  
    myStepper.step(stepsPerRevolution);

    // myStepper.step(stepsPerRevolution);


    // if (millis() - lastPublish >= 60000)
    // {
    //     Particle.publish("UVPULL");
    //     Serial.println("print");
    //     lastPublish = millis();
    // }
    if (millis() - lastPublish >= 1800000)
        {
            Particle.publish("UVPULL");
            // Particle.subscribe("hook-response/UVPULL/0", extractInfo);
            Serial.println("print");
            lastPublish = millis();
            
            // for (int i = 0; i < 5; i++)
            // {
            //     myStepper.step(stepsPerRevolution);
            // }
            
        }
    

    
    
}

void extractInfo(const char *event, const char *data)
{
    Serial.println("Handler is starting...");
    
    deserializeJson(doc, data);
    
    //JsonObject root_0 = doc[0];
    float uvIndex = doc["now"]["uvi"];
    
    Serial.print("uv");
    Serial.println(uvIndex);
    
    // for (int i = 0; i < 5; i++)
    // {
    //     myStepper.step(stepsPerRevolution);
    // }
    // Constant Movement Motor relating to speed
    // Another option is just a few spins at top speed every 10 minutes or something or *** every time the light updates ***
    // if (uvIndex == 0)
    // {
    //     stepperSpeed = 0;
    // }
    // else if (uvIndex <= 1)
    // {
    //     stepperSpeed = 10 + (0.5 - (0.5 * (10 - uvIndex)));
    // }
    // else if (uvIndex <= 2)
    // {
    //     stepperSpeed = 10.5 + (0.5 - (0.5 * (10 - uvIndex)));
    // }else if (uvIndex <= 3)
    // {
    //     stepperSpeed = 11 + (0.5 - (0.5 * (10 - uvIndex)));
    // }else if (uvIndex <= 4)
    // {
    //     stepperSpeed = 11.5 + (0.5 - (0.5 * (10 - uvIndex)));
    // }else if (uvIndex <= 5)
    // {
    //     stepperSpeed = 12 + (0.5 - (0.5 * (10 - uvIndex)));
    // }else if (uvIndex <= 6)
    // {
    //     stepperSpeed = 12.5 + (0.5 - (0.5 * (10 - uvIndex)));
    // }else if (uvIndex <= 7)
    // {
    //     stepperSpeed = 13 + (0.5 - (0.5 * (10 - uvIndex)));
    // }else if (uvIndex <= 8)
    // {
    //     stepperSpeed = 13.5 + (0.5 - (0.5 * (10 - uvIndex)));
    // }else if (uvIndex <= 9)
    // {
    //     stepperSpeed = 14 + (0.5 - (0.5 * (10 - uvIndex)));
    // }else if (uvIndex <= 10)
    // {
    //     stepperSpeed = 14.5 + (0.5 - (0.5 * (10 - uvIndex)));
    // }
    
    
    
    
    
    
    
    brightness = uvIndex * 10;
    Serial.print("Brightness");
    Serial.println(brightness);
    Serial.print("Speed");
    Serial.println(stepperSpeed);
    
    // for (int i = 0; i < 8; i++)
    //     {
    //         strip.setPixelColor(i, 150, 80, 20);
    //         strip.setBrightness(uvIndex * 10);
    //         strip.show();
    //     }
    
    
    
}