// Learn about the ESP32 WiFi simulation in
// https://docs.wokwi.com/guides/esp32-wifi

#include <WiFi.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C LCD = LiquidCrystal_I2C(0x27, 16, 2);

#define NTP_SERVER     "tock.stdtime.gov.tw"
#define UTC_OFFSET     0
#define UTC_OFFSET_DST 0
#define METER_PIN 13
#define RELAY_PIN 12

void spinner() {
  static int8_t counter = 0;
  const char* glyphs = "\xa1\xa5\xdb";
  int i = 0;
  while(i > 0) {
    LCD.setCursor(i, 1);
    LCD.print(glyphs[counter++]);
  }
   if (counter == strlen(glyphs)) {
      counter = 0;
}
}

void readknob() {
  int value = analogRead(METER_PIN);

  value = map(value, 0, 4095, 0, 100);  

  // int brightness = 2.5 * value;
  // digitalWrite(RELAY_PIN, brightness);

  if (value == 100) {
    digitalWrite(RELAY_PIN, HIGH); 
  } else {
    digitalWrite(RELAY_PIN, LOW); 
  } 

  LCD.setCursor(7, 0);
  LCD.println(value);
  Serial.println(value);
}

void setup() {
  Serial.begin(115200);

  pinMode(METER_PIN, INPUT);
  pinMode(RELAY_PIN, OUTPUT);

  LCD.init();
  LCD.backlight();
  LCD.setCursor(0, 0);
}

void loop() {
  readknob();
  spinner();
  delay(100);
}