#include <stdint.h>
#include <math.h>

static void delay_ms(uint32_t ms) {
  for (uint32_t i = 0; i < ms * 6000; i++) {
    __asm volatile ("nop");
  }
}

static void uart2_write_char(char c) {
  while (!(USART2->ISR & (1 << 7)));
  USART2->TDR = c;
}

static void uart2_write_string(const char *s) {
  while (*s) uart2_write_char(*s++);
}

static void uart2_write_number(uint32_t n) {
  char buf[12];
  int i = 0;

  if (n == 0) {
    uart2_write_char('0');
    return;
  }

  while (n > 0) {
    buf[i++] = '0' + (n % 10);
    n /= 10;
  }

  while (i > 0) uart2_write_char(buf[--i]);
}

static void gpio_init(void) {
  RCC->IOPENR |= (1 << 0);

  GPIOA->MODER &= ~(3 << (0 * 2));
  GPIOA->MODER |=  (3 << (0 * 2));

  GPIOA->MODER &= ~(3 << (2 * 2));
  GPIOA->MODER |=  (2 << (2 * 2));
  GPIOA->AFR[0] &= ~(0xF << (2 * 4));
  GPIOA->AFR[0] |=  (1 << (2 * 4));

  GPIOA->MODER &= ~(3 << (8 * 2));
  GPIOA->MODER |=  (2 << (8 * 2));
  GPIOA->AFR[1] &= ~(0xF << ((8 - 8) * 4));
  GPIOA->AFR[1] |=  (2 << ((8 - 8) * 4));
}

static void uart2_init(void) {
  RCC->APBENR1 |= (1 << 17);

  USART2->CR1 = 0;
  USART2->BRR = 417;
  USART2->CR1 |= (1 << 3);
  USART2->CR1 |= (1 << 0);
}

static void adc1_init(void) {
  RCC->APBENR2 |= (1 << 20);

  ADC1->CR &= ~(1 << 0);
  ADC1->CR |= (1 << 31);
  while (ADC1->CR & (1 << 31));

  ADC1->CHSELR = (1 << 0);
  ADC1->SMPR = 0x7;

  ADC1->CR |= (1 << 0);
  while (!(ADC1->ISR & (1 << 0)));
}

static uint16_t adc1_read(void) {
  ADC1->CHSELR = (1 << 0);
  ADC1->CR |= (1 << 2);

  while (!(ADC1->ISR & (1 << 2)));

  return (uint16_t)(ADC1->DR & 0x0FFF);
}

static void tim1_pwm_init(void) {
  RCC->APBENR2 |= (1 << 11);

  TIM1->PSC = 47;
  TIM1->ARR = 19999;

  TIM1->CCMR1 &= ~(7 << 4);
  TIM1->CCMR1 |=  (6 << 4);
  TIM1->CCMR1 |=  (1 << 3);

  TIM1->CCER |= (1 << 0);
  TIM1->BDTR |= (1 << 15);

  TIM1->CCR1 = 1000;

  TIM1->EGR |= (1 << 0);
  TIM1->CR1 |= (1 << 7);
  TIM1->CR1 |= (1 << 0);
}

static void servo_set_angle(uint32_t angle) {
  if (angle > 180) angle = 180;

  uint32_t pulse_us = 1000 + ((angle * 1000) / 180);
  TIM1->CCR1 = pulse_us;
}

void setup() {
  gpio_init();
  uart2_init();
  adc1_init();
  tim1_pwm_init();

  uart2_write_string("Temperature-Based Smart Cooling Vent Controller\r\n");
}

void loop() {
  uint16_t adc_value = adc1_read();

  // ADC değeri sıcaklık seviyesi gibi ölçekleniyor
  float temperature_f = 1.0f / (logf(1.0f / (4095.0f / adc_value - 1.0f)) / 3950.0f + 1.0f / 298.15f) - 273.15f;
int32_t temperature = (int32_t)temperature_f;

  uint32_t angle;

  if (temperature < 25) {
    angle = 0;
  } else if (temperature > 75) {
    angle = 180;
  } else {
    angle = ((temperature - 25) * 180) / 50;
  }

  servo_set_angle(angle);

  uart2_write_string("ADC: ");
  uart2_write_number(adc_value);
  uart2_write_string(" | Temp Level: ");
  uart2_write_number(temperature);
  uart2_write_string(" C | Servo Angle: ");
  uart2_write_number(angle);
  uart2_write_string(" deg\r\n");

  delay_ms(100);
}