// STM32 Nucleo-L031K6 HAL Blink + printf() example
// Simulation: https://wokwi.com/projects/367244067477216257
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <stm32l0xx_hal.h>
#include <stm32l0xx.h>

void SystemClock_Config(void);
uint16_t adc_init_and_read_PA0(void);


int main(void)
{
  RCC->IOPENR |= (1<<1);
  GPIOB->MODER &= ~(0x3 << (3 * 2));
  GPIOB->MODER |=  (0x1 << (3 * 2)); // MODER0 = 11b
  GPIOB->ODR |= (0 << 3);
  HAL_Init();
  SystemClock_Config();
  uint16_t valor_adc = adc_init_and_read_PA0();
  while(1){
    valor_adc = adc_init_and_read_PA0();
    if (valor_adc > 4000) GPIOB->ODR |= (1 << 3);
    //else GPIOB-> &= ~(1 << 3);
  }
  
}

#include <stdint.h>

uint16_t adc_init_and_read_PA0(void) {
    // 1. Habilita clocks: GPIOA e ADC
    RCC->IOPENR |= (1 << 0);   // GPIOAEN
    RCC->APB2ENR |= (1 << 9);  // ADCEN

    // 2. Configura PA0 como analógico
    GPIOA->MODER &= ~(0x3 << (0 * 2));
    GPIOA->MODER |=  (0x3 << (0 * 2)); // MODER0 = 11b

    // 3. Ativa regulador interno do ADC
    ADC1->CR &= ~(0b11 << 28);
    ADC1->CR |=  (0b01 << 28); // ADVREGEN = 01 (intermediate)
    for (volatile int i = 0; i < 1000; ++i); // Delay simples
    ADC1->CR &= ~(0b11 << 28);
    ADC1->CR |=  (0b10 << 28); // ADVREGEN = 10 (enabled)
    for (volatile int i = 0; i < 1000; ++i); // Delay simples

    // 4. Calibração
    ADC1->CR |= (1 << 31); // ADCAL = 1
    while (ADC1->CR & (1 << 31)); // Espera calibrar

    // 5. Habilita o ADC
    ADC1->CR |= (1 << 0); // ADEN
    while (!(ADC1->ISR & (1 << 0))); // Espera ADRDY = 1

    // 6. Seleciona canal 0 (PA0 = ADC_IN0)
    ADC1->CHSELR = (1 << 0); // Seleciona canal 0

    // 7. Inicia conversão
    ADC1->CR |= (1 << 2); // ADSTART

    // 8. Espera fim da conversão
    while (!(ADC1->ISR & (1 << 2))); // EOC = 1

    // 9. Lê resultado
    return (uint16_t)(ADC1->DR & 0xFFFF);
}



void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
  RCC_PeriphCLKInitTypeDef PeriphClkInit = {0};

  /** Configure the main internal regulator output voltage
  */
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);

  /** Initializes the RCC Oscillators according to the specified parameters
    in the RCC_OscInitTypeDef structure.
  */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
  RCC_OscInitStruct.HSIState = RCC_HSI_ON;
  RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI;
  RCC_OscInitStruct.PLL.PLLMUL = RCC_PLLMUL_4;
  RCC_OscInitStruct.PLL.PLLDIV = RCC_PLLDIV_2;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    Error_Handler();
  }

  /** Initializes the CPU, AHB and APB buses clocks
  */
  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_SYSCLK
                                | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_1) != HAL_OK)
  {
    Error_Handler();
  }
  PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_USART2;
  PeriphClkInit.Usart2ClockSelection = RCC_USART2CLKSOURCE_PCLK1;
  if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit) != HAL_OK)
  {
    Error_Handler();
  }
}


void Error_Handler(void)
{
  /* User can add his own implementation to report the HAL error return state */
}