UV Index Monitor: Sunburn Protection System for Indian Outdoors

A UV index monitor helps protect against harmful ultraviolet radiation, a growing concern in India where outdoor workers, school children, and athletes are exposed to some of the highest UV levels in the world. With India’s tropical location, UV index values regularly exceed 10 (very high) during summer months, especially at higher altitudes in Ladakh, Himachal Pradesh, and Uttarakhand. This project guide covers building a portable UV monitor with Arduino that displays the current UV index and provides sunburn time estimates.

Table of Contents

• UV Radiation in India
• UV Sensor Options: VEML6075 vs ML8511
• Building the UV Monitor
• UV Index Calculation
• Sunburn Time Estimation
• Frequently Asked Questions
• Conclusion

UV Radiation in India

The UV index in Indian cities typically ranges from 6-8 in winter (moderate-high) to 10-14 in summer (very high to extreme). High-altitude regions see even higher values. Despite this, UV awareness in India is low. Most outdoor workers (construction, agriculture, delivery) have no UV protection. Schools rarely monitor UV for outdoor play decisions.

UV Sensor Options: VEML6075 vs ML8511

The VEML6075 is recommended for its separate UVA and UVB readings, which allow more accurate UV index calculation and differentiation between skin-damaging UVB and deeper-penetrating UVA.

Building the UV Monitor

// UV Monitor Wiring (Arduino Uno)
// VEML6075: VCC→3.3V, GND→GND, SDA→A4, SCL→A5
// SSD1306 OLED: VCC→5V, GND→GND, SDA→A4, SCL→A5
// Buzzer: Pin D8
// Button (mode): Pin D2

#include <Wire.h>
#include <Adafruit_VEML6075.h>
#include <Adafruit_SSD1306.h>

Adafruit_VEML6075 uv = Adafruit_VEML6075();
Adafruit_SSD1306 display(128, 64, &Wire, -1);

void setup() {
  uv.begin();
  uv.setIntegrationTime(VEML6075_100MS);
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
}

void loop() {
  float uvIndex = uv.readUVI();
  float uva = uv.readUVA();
  float uvb = uv.readUVB();
  
  display.clearDisplay();
  display.setTextSize(2);
  display.setCursor(0, 0);
  display.print("UV: ");
  display.println(uvIndex, 1);
  
  display.setTextSize(1);
  display.print("UVA: "); display.println(uva, 0);
  display.print("UVB: "); display.println(uvb, 0);
  
  // Risk level
  display.setCursor(0, 48);
  if (uvIndex < 3) display.println("LOW - Safe");
  else if (uvIndex < 6) display.println("MODERATE - Hat advised");
  else if (uvIndex < 8) display.println("HIGH - Sunscreen needed");
  else if (uvIndex < 11) display.println("VERY HIGH - Limit exposure");
  else display.println("EXTREME - Stay indoors!");
  
  display.display();
  delay(5000);
}

UV Index Calculation

The UV Index is a standardised scale developed by WHO. The VEML6075 sensor library includes a built-in UV index calculation using the formula: UVI = (UVA_weighted * UVA_coeff + UVB_weighted * UVB_coeff) * response_factor. The sensor handles compensation for visible and infrared light interference.

Sunburn Time Estimation

Time to sunburn depends on UV index and skin type. For Indian skin types (Fitzpatrick Type IV-V), approximate sunburn times are: UV index 6 = 60 minutes, UV index 8 = 45 minutes, UV index 10 = 30 minutes, UV index 12+ = under 20 minutes. Display this on the OLED as a countdown recommendation.

Frequently Asked Questions

Does UV penetrate through clouds in India?

Yes. Thin clouds only block 20-30% of UV radiation. On overcast monsoon days, UV index can still be 4-6 (moderate-high). Only thick, dark rain clouds significantly reduce UV. This is why UV monitoring is important even on cloudy days.

Is this useful for high-altitude trekkers?

Extremely useful. UV increases approximately 10-12% for every 1000 metres of altitude. At Rohtang Pass (3,978m), UV index can exceed 16, causing sunburn in under 10 minutes on unprotected skin. A portable UV monitor is essential trekking equipment for Ladakh and Himalayan regions.

Can this integrate with a weather station?

Yes. Add the VEML6075 to any ESP32-based weather station on the shared I2C bus. UV data adds valuable context for agricultural and health applications.

What is the power consumption?

The VEML6075 draws under 1mA. Total system (Arduino Nano + OLED + sensor) draws about 50mA. A 2000mAh power bank lasts over 40 hours, or add a small solar panel for indefinite outdoor operation.

Conclusion

A UV index monitor is a simple yet valuable project for Indian conditions where UV exposure is a genuine health concern. From school playgrounds to construction sites and trekking trails, knowing the current UV level enables informed decisions about sun protection. Build your UV monitor with components from Zbotic and help protect yourself and others from harmful UV radiation.