Sketch for VEML6070 for Wemos D1 Pro mini with OLED shield (using Adafruit library https://github.com/adafruit/Adafruit_VEML6070)

VEML6070.ino

#include <SPI.h>
#include <Wire.h>
#include <SFE_MicroOLED.h>
#include "Adafruit_VEML6070.h"

#define PIN_RESET 255  //
#define DC_JUMPER 0  // I2C Addres: 0 - 0x3C, 1 - 0x3D

MicroOLED oled(PIN_RESET, DC_JUMPER); // Example I2C declaration
Adafruit_VEML6070 uv = Adafruit_VEML6070();

int uvmax = 1;

void setup() {
  Serial.begin(9600);
  Serial.println("VEML6070 Test");
  uv.begin(VEML6070_1_T);  // pass in the integration time constant

  oled.begin();
  oled.clear(PAGE);
  oled.clear(ALL);
}


void loop() {

  // Read current UV data
  int uvcur = uv.readUV();
  oled.clear(PAGE);
  oled.setCursor(0, 0);
  oled.print("C: "); 
  oled.println(uvcur); 

  // UV maximum
  uvmax = (uvmax < uvcur)? uvcur : uvmax;
  oled.print("M: "); 
  oled.println(uvmax);

  // Percent of maximum
  float uvred = round(uvcur/(uvmax*0.01));
  oled.print("R: "); 
  oled.print(uvred);
  oled.print("%");
  
  oled.display(); 
  delay(500);
}