// STM32 Nucleo-C031C6 HAL Blink + printf() example
// Simulation: https://wokwi.com/projects/397396193711557633

#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <stm32c0xx_hal.h>

/*

 LEDs:
  LD1 COM: LD1 is a bi-colored LED. the LD1 default status is red.
  LD2 5V_USB_CHG: This red LED is ON when overcurrent is detected on USB VBUS.
  LD3 5V_PWR: This green LED is ON when the STM32 Nucleo-64 board is powered by 
  a 5 V source.
  LD4 USER: This green LED is a user LED connected to D13 ARDUINO® signal 
  corresponding to PA5 STM32 I/O

 Button:
  B1 USER: User and wake-up button connected to the PC13 I/O pin 3 of the STM32 microcontroller

 */

// ST Nucleo User LD4
#define LED_PORT                GPIOA
#define LED_PIN                 GPIO_PIN_5
// External LED (PB10)
#define EXT_LED_PORT            GPIOB
#define EXT_LED_PIN             GPIO_PIN_10

#define USART2_PORT             GPIOA
#define USART2_TX_PIN           GPIO_PIN_2
#define USART2_RX_PIN           GPIO_PIN_3

UART_HandleTypeDef huart2;

void SystemClock_Config(void);
static void MX_USART2_UART_Init(void);

void osSystickHandler(void)
{
  // 1 Hz blinking:
  if ((HAL_GetTick() % 500) == 0)
  {
    HAL_GPIO_TogglePin(LED_PORT, LED_PIN);
  }
}

void LED_init(void)
{
  __HAL_RCC_GPIOB_CLK_ENABLE();
  GPIO_InitTypeDef GPIO_Config = {0};

  GPIO_Config.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_Config.Pull = GPIO_NOPULL;
  GPIO_Config.Speed = GPIO_SPEED_FREQ_HIGH;
  GPIO_Config.Pin = LED_PIN;

  HAL_GPIO_Init(LED_PORT, &GPIO_Config);

  GPIO_Config.Pin = EXT_LED_PIN;
  HAL_GPIO_Init(EXT_LED_PORT, &GPIO_Config);

  HAL_GPIO_WritePin(LED_PORT, LED_PIN, GPIO_PIN_SET);
  HAL_GPIO_WritePin(EXT_LED_PORT, EXT_LED_PIN, GPIO_PIN_RESET); // default off
}

void userBtn_init(void)
{
  __HAL_RCC_GPIOC_CLK_ENABLE();
  GPIO_InitTypeDef GPIO_Config = {0};

  GPIO_Config.Mode = GPIO_MODE_INPUT;
  GPIO_Config.Pull = GPIO_NOPULL;
  GPIO_Config.Speed = GPIO_SPEED_FREQ_HIGH;
  GPIO_Config.Pin = GPIO_PIN_13;

  HAL_GPIO_Init(GPIOC, &GPIO_Config);

}

int main(void)
{
  HAL_Init();
  SystemClock_Config();

  LED_init();
  userBtn_init();
  MX_USART2_UART_Init();

  printf("Hello, STMicroelectronics!\n");
  printf("This is a HAL template for STM32C0\n");

  while (1)
  {
    HAL_GPIO_TogglePin(GPIOA, GPIO_PIN_5);
    HAL_GPIO_TogglePin(GPIOB, GPIO_PIN_10);
    HAL_Delay(500);
  }

  return 0;
}

/**
  * @brief System Clock Configuration
  * @retval None
  */
void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

  /** 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.HSIDiv = RCC_HSI_DIV1;
  RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
  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_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSI;
  RCC_ClkInitStruct.SYSCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_HCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_APB1_DIV1;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_1) != HAL_OK)
  {
    Error_Handler();
  }
}

/**
  * @brief USART2 Initialization Function
  * @param None
  * @retval None
  */
static void MX_USART2_UART_Init(void)
{

  /* USER CODE BEGIN USART2_Init 0 */
  __HAL_RCC_GPIOA_CLK_ENABLE();

  GPIO_InitTypeDef GPIO_InitStruct = {0};
  GPIO_InitStruct.Pin = USART2_TX_PIN | USART2_RX_PIN;
  GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
  GPIO_InitStruct.Alternate = GPIO_AF1_USART2;
  HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

  /* USER CODE END USART2_Init 0 */

  /* USER CODE BEGIN USART2_Init 1 */

  /* USER CODE END USART2_Init 1 */
  huart2.Instance = USART2;
  huart2.Init.BaudRate = 115200;
  huart2.Init.WordLength = UART_WORDLENGTH_8B;
  huart2.Init.StopBits = UART_STOPBITS_1;
  huart2.Init.Parity = UART_PARITY_NONE;
  huart2.Init.Mode = UART_MODE_TX_RX;
  huart2.Init.HwFlowCtl = UART_HWCONTROL_NONE;
  huart2.Init.OverSampling = UART_OVERSAMPLING_16;
  huart2.Init.OneBitSampling = UART_ONE_BIT_SAMPLE_DISABLE;
  huart2.Init.ClockPrescaler = UART_PRESCALER_DIV1;
  huart2.AdvancedInit.AdvFeatureInit = UART_ADVFEATURE_NO_INIT;
  if (HAL_UART_Init(&huart2) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN USART2_Init 2 */
  __HAL_RCC_USART2_CLK_ENABLE();
  /* USER CODE END USART2_Init 2 */

}


// The following makes printf() write to USART2:

#define STDOUT_FILENO   1
#define STDERR_FILENO   2

int _write(int file, uint8_t *ptr, int len)
{
  switch (file)
  {
    case STDOUT_FILENO:
      HAL_UART_Transmit(&huart2, ptr, len, HAL_MAX_DELAY);
      break;

    case STDERR_FILENO:
      HAL_UART_Transmit(&huart2, ptr, len, HAL_MAX_DELAY);
      break;

    default:
      return -1;
  }

  return len;
}