float vin = 0;
float vout = 0;
float R1 = 100000.0;
float R2 = 150000.0;

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

void loop() 
{
  float voltage = (float)analogRead(34);
  Serial.println(voltage);
  vout = (voltage * 3.3)/4096;
  vin = vout * (R1 + R2) / R2;
  Serial.print(vin,1);
  Serial.println("v");
  delay(1000);
}