#include <Adafruit_NeoPixel.h>

#define PIN_NEO_PIXEL 16  // The ESP32 pin GPIO16 connected to NeoPixel
#define NUM_PIXELS 30     // The number of LEDs (pixels) on NeoPixel LED strip

Adafruit_NeoPixel NeoPixel(NUM_PIXELS, PIN_NEO_PIXEL, NEO_GRB + NEO_KHZ800);
int tt=0;
int aa=4095/490;
void setup() {
  NeoPixel.begin();  // initialize NeoPixel strip object (REQUIRED)
  pinMode(12, INPUT);
  Serial.begin(115200);
}

// 0~4095 =   4k 4096  ==>  10ms~500ms

void loop() {

  

  NeoPixel.clear();  // set all pixel colors to 'off'. It only takes effect if pixels.show() is called

  // turn pixels to green one-by-one with delay between each pixel
  for (int pixel = 0; pixel < NUM_PIXELS; pixel++) {           // for each pixel
    NeoPixel.setPixelColor(pixel, NeoPixel.Color(0, 255, 0));  // it only takes effect if pixels.show() is called
    NeoPixel.show();                                           // update to the NeoPixel Led Strip
    
    int tt=analogRead(12);
    tt=tt/aa;
    if(tt>500)tt=500;
    if(tt<10)tt=10;
    
    Serial.println(tt);
    delay(tt);  // 200ms pause between each pixel
  }

  // turn off all pixels for two seconds
  NeoPixel.clear();
  NeoPixel.show();  // update to the NeoPixel Led Strip
  delay(20);      // 0.2 seconds off time

  // turn on all pixels to red at the same time for two seconds
  //for (int pixel = 0; pixel < NUM_PIXELS; pixel++) {           // for each pixel
  //  NeoPixel.setPixelColor(pixel, NeoPixel.Color(255, 0, 0));  // it only takes effect if pixels.show() is called
  //}
  //NeoPixel.show();  // update to the NeoPixel Led Strip
  //delay(10);      // 0.1 second on time

  // turn off all pixels for one seconds
  //NeoPixel.clear();
  //NeoPixel.show();  // update to the NeoPixel Led Strip
  //delay(10);      // 0.1 second off time 
}