#include <Arduino.h>

#define ledLOW LOW
#define ledHIGH HIGH

#ifdef ESP32
#define ledPin 2
#elif ARDUINONANO
#define ledPin 13
#elif STM32
#define ledPin PC13
#define ledLOW HIGH
#define ledHIGH LOW
#endif

double pi(int m)
{
  //https://create.arduino.cc/projecthub/colonel/calculating-pi-d85ea7
  double result = 4;
  for (int x = 1; x < m; x++)
  {
    result *= (2 * x);
    result /= (2 * x + 1);
    result *= (2 * x + 2);
    result /= (2 * x + 1);
  }
  return result;
}
void setup()
{
  // put your setup code here, to run once:
  pinMode(ledPin, OUTPUT);
  Serial.begin(115200);
}

void loop()
{
  //put your main code here, to run repeatedly :
  digitalWrite(ledPin, ledLOW);
  Serial.println("benchmark started.");
  auto duration = millis();
  double total = 0;
  for (int i = 0; i < 700; i++)
  {
    auto result = pi(i);
    total += result;
  }
  Serial.println(total);
  duration = millis() - duration;
  Serial.write("finished in ms: ");
  Serial.println(duration);
  digitalWrite(ledPin, ledHIGH);
  while (1)
  {
    delay(1000);
  }
}