问如何在Arduino IDE中将4.15V锂离子电池的电池电压转换成电池百分比？(我在做某种LED电池指示器)

EN

int battery_pin = A3;

float battery_read()
{
    //read battery voltage per %
    long sum = 0;                   // sum of samples taken
    float voltage = 0.0;            // calculated voltage
    float output = 0.0;             //output value
    const float battery_max = 4.20; //maximum voltage of battery
    const float battery_min = 3.0;  //minimum voltage of battery before shutdown

    for (int i = 0; i < 500; i++)
    {
        sum += analogRead(battery_pin);
        delayMicroseconds(1000);
    }
    // calculate the voltage
    voltage = sum / (float)500;
    // voltage = (voltage * 5.0) / 1023.0; //for default reference voltage
    voltage = (voltage * 1.1) / 1023.0; //for internal 1.1v reference
    //round value by two precision
    voltage = roundf(voltage * 100) / 100;
    Serial.print("voltage: ");
    Serial.println(voltage, 2);
    output = ((voltage - battery_min) / (battery_max - battery_min)) * 100;
    if (output < 100)
        return output;
    else
        return 100.0f;
}

void setup()
{
    analogReference(INTERNAL); //set reference voltage to internal
    Serial.begin(9600);
}

void loop()
{
    Serial.print("Battery Level: ");
    Serial.println(battery_read(), 2);
    delay(1000);
}

void loop() {
  float vPow = 5.0;
  float r1 = 100000;
  float r2 = 10000;

  float v = (analogRead(A0) * vPow) / 1024.0;
  float v2 = v / (r2 / (r1 + r2));
  
  float top = 4.2;
  float bottom = 3.6;
  float range = top - bottom;
  float rangeVolts = v2 - bottom;
  int percent = (rangeVolts / range) * 100;
  
  if(percent > 100){
    percent = 100;
  }
  if(percent < 0) {
    percent = 0;
  }
  
  Serial.print("percent ");
  Serial.println(percent);
  
  delay(1000);
}