/*
 * Arduino Sampling Rate Test
 * Tests actual sampling rate for analog and digital reads
 */

// Test configuration
#define TEST_PIN A0              // Analog pin to test
#define SAMPLE_COUNT 10000       // Number of samples to take
#define WARMUP_SAMPLES 100       // Warmup samples to stabilize

void setup() {
  Serial.begin(115200);
  while (!Serial) {
    ; // Wait for serial port to connect (needed for native USB)
  }
  
  Serial.println("Arduino Sampling Rate Test");
  Serial.println("==========================");
  
  // Print board info
  #if defined(ARDUINO_AVR_UNO)
    Serial.println("Board: Arduino Uno");
  #elif defined(ARDUINO_AVR_MEGA2560)
    Serial.println("Board: Arduino Mega 2560");
  #elif defined(ARDUINO_AVR_NANO)
    Serial.println("Board: Arduino Nano");
  #elif defined(ARDUINO_SAM_DUE)
    Serial.println("Board: Arduino Due");
  #elif defined(ARDUINO_ARCH_ESP32)
    Serial.println("Board: ESP32");
  #elif defined(ARDUINO_ARCH_ESP8266)
    Serial.println("Board: ESP8266");
  #else
    Serial.println("Board: Unknown/Generic Arduino");
  #endif
  
  Serial.print("CPU Frequency: ");
  Serial.print(F_CPU / 1000000);
  Serial.println(" MHz");
  Serial.println();
  
  delay(2000);
}

void loop() {
  // Test 1: Analog Read Sampling Rate
  testAnalogSamplingRate();
  
  delay(3000);
  
  // Test 2: Digital Read Sampling Rate
  testDigitalSamplingRate();
  
  delay(3000);
  
  // Test 3: Analog Read with Different Prescalers
  testAnalogPrescalers();
  
  Serial.println("\nTests complete. Restarting in 10 seconds...\n");
  delay(10000);
}

void testAnalogSamplingRate() {
  Serial.println("Test 1: Analog Read Sampling Rate");
  Serial.println("----------------------------------");
  
  // Warmup
  for (int i = 0; i < WARMUP_SAMPLES; i++) {
    analogRead(TEST_PIN);
  }
  
  // Measure sampling rate
  unsigned long startTime = micros();
  
  for (long i = 0; i < SAMPLE_COUNT; i++) {
    analogRead(TEST_PIN);
  }
  
  unsigned long endTime = micros();
  unsigned long duration = endTime - startTime;
  
  // Calculate results
  float samplesPerSecond = (SAMPLE_COUNT * 1000000.0) / duration;
  float microsPerSample = (float)duration / SAMPLE_COUNT;
  
  Serial.print("Samples taken: ");
  Serial.println(SAMPLE_COUNT);
  Serial.print("Total time: ");
  Serial.print(duration);
  Serial.println(" us");
  Serial.print("Time per sample: ");
  Serial.print(microsPerSample, 2);
  Serial.println(" us");
  Serial.print("Sampling rate: ");
  Serial.print(samplesPerSecond, 2);
  Serial.println(" samples/second");
  Serial.print("Sampling rate: ");
  Serial.print(samplesPerSecond / 1000.0, 2);
  Serial.println(" kHz");
  Serial.println();
}

void testDigitalSamplingRate() {
  Serial.println("Test 2: Digital Read Sampling Rate");
  Serial.println("-----------------------------------");
  
  pinMode(2, INPUT);
  
  // Warmup
  for (int i = 0; i < WARMUP_SAMPLES; i++) {
    digitalRead(2);
  }
  
  // Measure sampling rate
  unsigned long startTime = micros();
  
  for (long i = 0; i < SAMPLE_COUNT; i++) {
    digitalRead(2);
  }
  
  unsigned long endTime = micros();
  unsigned long duration = endTime - startTime;
  
  // Calculate results
  float samplesPerSecond = (SAMPLE_COUNT * 1000000.0) / duration;
  float microsPerSample = (float)duration / SAMPLE_COUNT;
  
  Serial.print("Samples taken: ");
  Serial.println(SAMPLE_COUNT);
  Serial.print("Total time: ");
  Serial.print(duration);
  Serial.println(" us");
  Serial.print("Time per sample: ");
  Serial.print(microsPerSample, 2);
  Serial.println(" us");
  Serial.print("Sampling rate: ");
  Serial.print(samplesPerSecond, 2);
  Serial.println(" samples/second");
  Serial.print("Sampling rate: ");
  Serial.print(samplesPerSecond / 1000.0, 2);
  Serial.println(" kHz");
  Serial.println();
}

void testAnalogPrescalers() {
  Serial.println("Test 3: Analog Read with Different ADC Prescalers");
  Serial.println("--------------------------------------------------");
  Serial.println("(Note: This test is for AVR boards like Uno, Mega, Nano)");
  
  #if defined(__AVR__)
  byte prescalers[] = {16, 32, 64, 128};
  byte prescalerBits[] = {
    0b100,  // 16
    0b101,  // 32
    0b110,  // 64
    0b111   // 128 (default)
  };
  
  for (int i = 0; i < 4; i++) {
    // Set ADC prescaler
    ADCSRA = (ADCSRA & 0xF8) | prescalerBits[i];
    
    // Warmup
    for (int j = 0; j < WARMUP_SAMPLES; j++) {
      analogRead(TEST_PIN);
    }
    
    // Measure
    unsigned long startTime = micros();
    for (long j = 0; j < SAMPLE_COUNT; j++) {
      analogRead(TEST_PIN);
    }
    unsigned long endTime = micros();
    unsigned long duration = endTime - startTime;
    
    float samplesPerSecond = (SAMPLE_COUNT * 1000000.0) / duration;
    
    Serial.print("Prescaler ");
    Serial.print(prescalers[i]);
    Serial.print(": ");
    Serial.print(samplesPerSecond / 1000.0, 2);
    Serial.println(" kHz");
  }
  
  // Restore default prescaler
  ADCSRA = (ADCSRA & 0xF8) | 0b111;
  
  #else
  Serial.println("Prescaler adjustment only available on AVR boards");
  #endif
  
  Serial.println();
}