/* USER CODE BEGIN Header */
/**
  ******************************************************************************
  * @file           : main.c
  * @brief          : Main program body
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2026 STMicroelectronics.
  * All rights reserved.
  *
  * This software is licensed under terms that can be found in the LICENSE file
  * in the root directory of this software component.
  * If no LICENSE file comes with this software, it is provided AS-IS.
  *
  ******************************************************************************
  */
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"

/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include <stdbool.h>
/* USER CODE END Includes */

/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */

/* USER CODE END PTD */

/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */

/* USER CODE END PD */

/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */

/* USER CODE END PM */

/* Private variables ---------------------------------------------------------*/
ADC_HandleTypeDef hadc1;

PCD_HandleTypeDef hpcd_USB_DRD_FS;

/* USER CODE BEGIN PV */

/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_ADC1_Init(void);
static void MX_USB_PCD_Init(void);
/* USER CODE BEGIN PFP */
uint16_t ADC_ReadChannel(uint32_t channel);
/* USER CODE END PFP */

/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */

void H_bridge_delay()
{
  // very rough calculation: body of the loop takes 8 instructions,
  // freq is 12 MHz: 8 / 12e6 * 100 = 0.000066 s, so about 66 ns
  // This calculation could be way off, but it doesn't matter that much
  volatile uint32_t delay = 100;
  while(--delay > 0) {}
}

void H_bridge_turn_off()
{
  HAL_GPIO_WritePin(LS_A_GPIO_Port, LS_A_Pin, GPIO_PIN_RESET);
  HAL_GPIO_WritePin(LS_B_GPIO_Port, LS_B_Pin, GPIO_PIN_RESET);
  HAL_GPIO_WritePin(HS_A_GPIO_Port, HS_A_Pin, GPIO_PIN_RESET);
  HAL_GPIO_WritePin(HS_B_GPIO_Port, HS_B_Pin, GPIO_PIN_RESET);
}

void H_bridge_set_direction(bool positive)
{
  H_bridge_turn_off();
  // delay to make sure all FETs are turned off;
  // not measured, just eyeballing the time
  H_bridge_delay();
  if (positive)
  {
    HAL_GPIO_WritePin(HS_A_GPIO_Port, HS_A_Pin, GPIO_PIN_SET);
    HAL_GPIO_WritePin(LS_B_GPIO_Port, LS_B_Pin, GPIO_PIN_SET);
  }
  else
  {

    HAL_GPIO_WritePin(HS_B_GPIO_Port, HS_B_Pin, GPIO_PIN_SET);
    HAL_GPIO_WritePin(LS_A_GPIO_Port, LS_A_Pin, GPIO_PIN_SET);
  }
}

/* USER CODE END 0 */

/**
  * @brief  The application entry point.
  * @retval int
  */
int main(void)
{

  /* USER CODE BEGIN 1 */

  /* USER CODE END 1 */

  /* MCU Configuration--------------------------------------------------------*/

  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
  HAL_Init();

  /* USER CODE BEGIN Init */

  /* USER CODE END Init */

  /* Configure the system clock */
  SystemClock_Config();

  /* USER CODE BEGIN SysInit */

  /* USER CODE END SysInit */

  /* Initialize all configured peripherals */
  MX_GPIO_Init();
  MX_ADC1_Init();
  MX_USB_PCD_Init();
  /* USER CODE BEGIN 2 */
  H_bridge_turn_off();
  H_bridge_set_direction(true);
  /* USER CODE END 2 */

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  GPIO_PinState state = GPIO_PIN_RESET;
  const uint32_t polarity_switch_period_ms = 5;
  uint32_t next_polarity_switch_ms = HAL_GetTick() + polarity_switch_period_ms;
  bool polarity = true;
  while (1)
  {
    /* USER CODE END WHILE */
    // Read voltages before and after current limiting resistor (R22, 10 ohm)
    uint16_t val_ch0 = ADC_ReadChannel(ADC_CHANNEL_0);
    uint16_t val_ch1 = ADC_ReadChannel(ADC_CHANNEL_1);
    // Convert to voltage (12-bit, 3.3V reference)
    const float adc_voltage_divider = 2.0f;
    float voltage_ch0 = (val_ch0 * 3.3f) / 4095.0f * adc_voltage_divider;
    float voltage_ch1 = (val_ch1 * 3.3f) / 4095.0f * adc_voltage_divider;

    // simple regulation
    const float target_voltage = 3.0f;
    if (voltage_ch0 < target_voltage)
    {
      state = GPIO_PIN_SET;
    } else {
      state = GPIO_PIN_RESET;
    }
    HAL_GPIO_WritePin(VDD_LEDL_EN_GPIO_Port, VDD_LEDL_EN_Pin, state);
    if (HAL_GetTick() > next_polarity_switch_ms)
    {
        next_polarity_switch_ms = HAL_GetTick() + polarity_switch_period_ms;
        polarity = !polarity;
        H_bridge_set_direction(polarity);
    }
    /* USER CODE BEGIN 3 */
  }
  /* USER CODE END 3 */
}

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

  __HAL_FLASH_SET_LATENCY(FLASH_LATENCY_0);

  /** Initializes the RCC Oscillators according to the specified parameters
  * in the RCC_OscInitTypeDef structure.
  */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI|RCC_OSCILLATORTYPE_HSI48;
  RCC_OscInitStruct.HSIState = RCC_HSI_ON;
  RCC_OscInitStruct.HSIDiv = RCC_HSI_DIV4;
  RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
  RCC_OscInitStruct.HSI48State = RCC_HSI48_ON;

  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_0) != HAL_OK)
  {
    Error_Handler();
  }
}

/**
  * @brief ADC1 Initialization Function
  * @param None
  * @retval None
  */
static void MX_ADC1_Init(void)
{

  /* USER CODE BEGIN ADC1_Init 0 */

  /* USER CODE END ADC1_Init 0 */

  ADC_ChannelConfTypeDef sConfig = {0};

  /* USER CODE BEGIN ADC1_Init 1 */

  /* USER CODE END ADC1_Init 1 */

  /** Configure the global features of the ADC (Clock, Resolution, Data Alignment and number of conversion)
  */
  hadc1.Instance = ADC1;
  hadc1.Init.ClockPrescaler = ADC_CLOCK_SYNC_PCLK_DIV1;
  hadc1.Init.Resolution = ADC_RESOLUTION_12B;
  hadc1.Init.DataAlign = ADC_DATAALIGN_RIGHT;
  hadc1.Init.ScanConvMode = ADC_SCAN_SEQ_FIXED;
  hadc1.Init.EOCSelection = ADC_EOC_SINGLE_CONV;
  hadc1.Init.LowPowerAutoWait = DISABLE;
  hadc1.Init.LowPowerAutoPowerOff = DISABLE;
  hadc1.Init.ContinuousConvMode = DISABLE;
  hadc1.Init.NbrOfConversion = 1;
  hadc1.Init.DiscontinuousConvMode = DISABLE;
  hadc1.Init.ExternalTrigConv = ADC_SOFTWARE_START;
  hadc1.Init.ExternalTrigConvEdge = ADC_EXTERNALTRIGCONVEDGE_NONE;
  hadc1.Init.DMAContinuousRequests = DISABLE;
  hadc1.Init.Overrun = ADC_OVR_DATA_PRESERVED;
  hadc1.Init.SamplingTimeCommon1 = ADC_SAMPLETIME_1CYCLE_5;
  hadc1.Init.OversamplingMode = DISABLE;
  hadc1.Init.TriggerFrequencyMode = ADC_TRIGGER_FREQ_HIGH;
  if (HAL_ADC_Init(&hadc1) != HAL_OK)
  {
    Error_Handler();
  }

  /** Configure Regular Channel
  */
  sConfig.Channel = ADC_CHANNEL_0;
  sConfig.Rank = ADC_RANK_CHANNEL_NUMBER;
  if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
  {
    Error_Handler();
  }

  /** Configure Regular Channel
  */
  sConfig.Channel = ADC_CHANNEL_1;
  if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN ADC1_Init 2 */

  /* USER CODE END ADC1_Init 2 */

}

/**
  * @brief USB Initialization Function
  * @param None
  * @retval None
  */
static void MX_USB_PCD_Init(void)
{

  /* USER CODE BEGIN USB_Init 0 */

  /* USER CODE END USB_Init 0 */

  /* USER CODE BEGIN USB_Init 1 */

  /* USER CODE END USB_Init 1 */
  hpcd_USB_DRD_FS.Instance = USB_DRD_FS;
  hpcd_USB_DRD_FS.Init.dev_endpoints = 8;
  hpcd_USB_DRD_FS.Init.speed = USBD_FS_SPEED;
  hpcd_USB_DRD_FS.Init.phy_itface = PCD_PHY_EMBEDDED;
  hpcd_USB_DRD_FS.Init.Sof_enable = DISABLE;
  hpcd_USB_DRD_FS.Init.low_power_enable = DISABLE;
  hpcd_USB_DRD_FS.Init.lpm_enable = DISABLE;
  hpcd_USB_DRD_FS.Init.battery_charging_enable = DISABLE;
  hpcd_USB_DRD_FS.Init.vbus_sensing_enable = DISABLE;
  hpcd_USB_DRD_FS.Init.bulk_doublebuffer_enable = DISABLE;
  hpcd_USB_DRD_FS.Init.iso_singlebuffer_enable = DISABLE;
  if (HAL_PCD_Init(&hpcd_USB_DRD_FS) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN USB_Init 2 */

  /* USER CODE END USB_Init 2 */

}

/**
  * @brief GPIO Initialization Function
  * @param None
  * @retval None
  */
static void MX_GPIO_Init(void)
{
  GPIO_InitTypeDef GPIO_InitStruct = {0};
  /* USER CODE BEGIN MX_GPIO_Init_1 */

  /* USER CODE END MX_GPIO_Init_1 */

  /* GPIO Ports Clock Enable */
  __HAL_RCC_GPIOA_CLK_ENABLE();
  __HAL_RCC_GPIOB_CLK_ENABLE();

  /*Configure GPIO pin Output Level */
  HAL_GPIO_WritePin(GPIOA, HS_B_Pin|LS_B_Pin|LS_A_Pin|HS_A_Pin, GPIO_PIN_RESET);

  /*Configure GPIO pin Output Level */
  HAL_GPIO_WritePin(VDD_LEDL_EN_GPIO_Port, VDD_LEDL_EN_Pin, GPIO_PIN_RESET);

  /*Configure GPIO pins : HS_B_Pin LS_B_Pin LS_A_Pin HS_A_Pin */
  GPIO_InitStruct.Pin = HS_B_Pin|LS_B_Pin|LS_A_Pin|HS_A_Pin;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
  HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

  /*Configure GPIO pin : VDD_LEDL_EN_Pin */
  GPIO_InitStruct.Pin = VDD_LEDL_EN_Pin;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
  HAL_GPIO_Init(VDD_LEDL_EN_GPIO_Port, &GPIO_InitStruct);

  /* USER CODE BEGIN MX_GPIO_Init_2 */

  /* USER CODE END MX_GPIO_Init_2 */
}

/* USER CODE BEGIN 4 */
uint16_t ADC_ReadChannel(uint32_t channel)
{
    ADC_ChannelConfTypeDef sConfig = {0};

    // Configure the specific channel
    sConfig.Channel = channel;
    sConfig.Rank = ADC_RANK_CHANNEL_NUMBER;
    if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
    {
        Error_Handler();
    }

    // Start conversion
    if (HAL_ADC_Start(&hadc1) != HAL_OK)
    {
        Error_Handler();
    }

    // Poll for completion (timeout 10ms)
    if (HAL_ADC_PollForConversion(&hadc1, 10) != HAL_OK)
    {
        Error_Handler();
    }

    // Get result
    uint16_t adc_value = HAL_ADC_GetValue(&hadc1);

    // Stop ADC
    HAL_ADC_Stop(&hadc1);

    return adc_value;
}
/* USER CODE END 4 */

/**
  * @brief  This function is executed in case of error occurrence.
  * @retval None
  */
void Error_Handler(void)
{
  /* USER CODE BEGIN Error_Handler_Debug */
  /* User can add his own implementation to report the HAL error return state */
  __disable_irq();
  while (1)
  {
  }
  /* USER CODE END Error_Handler_Debug */
}
#ifdef USE_FULL_ASSERT
/**
  * @brief  Reports the name of the source file and the source line number
  *         where the assert_param error has occurred.
  * @param  file: pointer to the source file name
  * @param  line: assert_param error line source number
  * @retval None
  */
void assert_failed(uint8_t *file, uint32_t line)
{
  /* USER CODE BEGIN 6 */
  /* User can add his own implementation to report the file name and line number,
     ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
  /* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */
