/* USER CODE BEGIN Header */
/**
  ******************************************************************************
  * @file           : main.c
  * @brief          : Main program body
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2024 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 "RFID.h"
#include <stdio.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 ---------------------------------------------------------*/
I2C_HandleTypeDef hi2c1;

SPI_HandleTypeDef hspi1;

UART_HandleTypeDef huart2;

/* USER CODE BEGIN PV */
/* Bitwise changed buffer */
uint8_t old_delta;
uint8_t delta;

#define DELTA_KP_BIT 0
#define DELTA_BTN_BIT 1
#define DELTA_CARD_PRESENT_BIT 2
#define DELTA_CARD_ID_BIT 3

uint8_t i2c_register;

// TODO: this doesn't need to be high and low, it can simply send 2 bytes
#define I2C_REGISTER_DELTA 1
#define I2C_REGISTER_KEYPAD 2
#define I2C_REGISTER_BUTTON 3
#define I2C_REGISTER_RFID_PRESENT 4
#define I2C_REGISTER_RFID_ID 5

uint16_t old_keypad_state = 0;
uint16_t keypad_state = 0;

uint16_t old_button_state = 0;
uint16_t button_state = 0;

uint8_t old_card_present = 0;
uint8_t card_present = 0;

#define CARD_ID_LEN 4
uint8_t old_card_id[CARD_ID_LEN] = {0};
uint8_t card_id[CARD_ID_LEN] = {0};
/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_I2C1_Init(void);
static void MX_SPI1_Init(void);
static void MX_USART2_UART_Init(void);
/* USER CODE BEGIN PFP */
#ifdef __GNUC__
/* With GCC/RAISONANCE, small printf (option LD Linker->Libraries->Small printf
   set to 'Yes') calls __io_putchar() */
#define PUTCHAR_PROTOTYPE int __io_putchar(int ch)
#else
#define PUTCHAR_PROTOTYPE int fputc(int ch, FILE *f)
#endif /* __GNUC__ */

void scan_keypad(void);
void scan_buttons(void);
void rfid_check_card(void);

void send_iterupt(void);

void printBinary(uint16_t num) {
    for (int i = 15; i >= 0; --i) {
        printf("%d", (num >> i) & 1);
    }
    printf("\r\n");
}
/* USER CODE END PFP */

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

/* 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_I2C1_Init();
  MX_SPI1_Init();
  MX_USART2_UART_Init();
  /* USER CODE BEGIN 2 */

  // rc522_init();
  HAL_I2C_EnableListen_IT(&hi2c1);
  // printf("initialized\r\n");

  /* USER CODE END 2 */

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {
	  // HAL_Delay(1);
	  scan_keypad();
	  scan_buttons();
	  // rfid_check_card();
	  send_iterupt();

//	  printf("s: %d\r\n", keypad_state);
//	  printf("r: %d\r\n", recv_cnt);
//	  printf("d: %d %d %d %d, %d %d %d %d\r\n", data[0], data[1], data[2], data[3], data[4], data[5], data[6], data[7]);

    /* USER CODE END WHILE */

    /* 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};

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

  /** Initializes the RCC Oscillators according to the specified parameters
  * in the RCC_OscInitTypeDef structure.
  */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
  RCC_OscInitStruct.HSEState = RCC_HSE_ON;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
  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_HSE;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0) != HAL_OK)
  {
    Error_Handler();
  }
}

/**
  * @brief I2C1 Initialization Function
  * @param None
  * @retval None
  */
static void MX_I2C1_Init(void)
{

  /* USER CODE BEGIN I2C1_Init 0 */

  /* USER CODE END I2C1_Init 0 */

  /* USER CODE BEGIN I2C1_Init 1 */

  /* USER CODE END I2C1_Init 1 */
  hi2c1.Instance = I2C1;
  hi2c1.Init.Timing = 0x2000090E;
  hi2c1.Init.OwnAddress1 = 252;
  hi2c1.Init.AddressingMode = I2C_ADDRESSINGMODE_7BIT;
  hi2c1.Init.DualAddressMode = I2C_DUALADDRESS_DISABLE;
  hi2c1.Init.OwnAddress2 = 0;
  hi2c1.Init.OwnAddress2Masks = I2C_OA2_NOMASK;
  hi2c1.Init.GeneralCallMode = I2C_GENERALCALL_DISABLE;
  hi2c1.Init.NoStretchMode = I2C_NOSTRETCH_DISABLE;
  if (HAL_I2C_Init(&hi2c1) != HAL_OK)
  {
    Error_Handler();
  }

  /** Configure Analogue filter
  */
  if (HAL_I2CEx_ConfigAnalogFilter(&hi2c1, I2C_ANALOGFILTER_ENABLE) != HAL_OK)
  {
    Error_Handler();
  }

  /** Configure Digital filter
  */
  if (HAL_I2CEx_ConfigDigitalFilter(&hi2c1, 0) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN I2C1_Init 2 */

  /* USER CODE END I2C1_Init 2 */

}

/**
  * @brief SPI1 Initialization Function
  * @param None
  * @retval None
  */
static void MX_SPI1_Init(void)
{

  /* USER CODE BEGIN SPI1_Init 0 */

  /* USER CODE END SPI1_Init 0 */

  /* USER CODE BEGIN SPI1_Init 1 */

  /* USER CODE END SPI1_Init 1 */
  /* SPI1 parameter configuration*/
  hspi1.Instance = SPI1;
  hspi1.Init.Mode = SPI_MODE_MASTER;
  hspi1.Init.Direction = SPI_DIRECTION_2LINES;
  hspi1.Init.DataSize = SPI_DATASIZE_8BIT;
  hspi1.Init.CLKPolarity = SPI_POLARITY_LOW;
  hspi1.Init.CLKPhase = SPI_PHASE_1EDGE;
  hspi1.Init.NSS = SPI_NSS_SOFT;
  hspi1.Init.BaudRatePrescaler = SPI_BAUDRATEPRESCALER_2;
  hspi1.Init.FirstBit = SPI_FIRSTBIT_MSB;
  hspi1.Init.TIMode = SPI_TIMODE_DISABLE;
  hspi1.Init.CRCCalculation = SPI_CRCCALCULATION_DISABLE;
  hspi1.Init.CRCPolynomial = 7;
  hspi1.Init.CRCLength = SPI_CRC_LENGTH_DATASIZE;
  hspi1.Init.NSSPMode = SPI_NSS_PULSE_ENABLE;
  if (HAL_SPI_Init(&hspi1) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN SPI1_Init 2 */

  /* USER CODE END SPI1_Init 2 */

}

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

  /* USER CODE BEGIN USART2_Init 0 */

  /* 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();
  }
  if (HAL_UARTEx_SetTxFifoThreshold(&huart2, UART_TXFIFO_THRESHOLD_1_8) != HAL_OK)
  {
    Error_Handler();
  }
  if (HAL_UARTEx_SetRxFifoThreshold(&huart2, UART_RXFIFO_THRESHOLD_1_8) != HAL_OK)
  {
    Error_Handler();
  }
  if (HAL_UARTEx_DisableFifoMode(&huart2) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN USART2_Init 2 */

  /* USER CODE END USART2_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_GPIOF_CLK_ENABLE();
  __HAL_RCC_GPIOA_CLK_ENABLE();
  __HAL_RCC_GPIOB_CLK_ENABLE();
  __HAL_RCC_GPIOC_CLK_ENABLE();
  __HAL_RCC_GPIOD_CLK_ENABLE();

  /*Configure GPIO pin Output Level */
  HAL_GPIO_WritePin(RFID_CS_GPIO_Port, RFID_CS_Pin, GPIO_PIN_RESET);

  /*Configure GPIO pin Output Level */
  HAL_GPIO_WritePin(RFID_RST_GPIO_Port, RFID_RST_Pin, GPIO_PIN_RESET);

  /*Configure GPIO pin Output Level */
  HAL_GPIO_WritePin(GPIOB, COL1_Pin|KP_C2_Pin|KP_C3_Pin|KP_C4_Pin, GPIO_PIN_SET);

  /*Configure GPIO pin Output Level */
  HAL_GPIO_WritePin(COL2_GPIO_Port, COL2_Pin, GPIO_PIN_SET);

  /*Configure GPIO pin Output Level */
  HAL_GPIO_WritePin(GPIOD, COL3_Pin|KP_C1_Pin, GPIO_PIN_SET);

  /*Configure GPIO pin : INT_Pin */
  GPIO_InitStruct.Pin = INT_Pin;
  GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
  GPIO_InitStruct.Alternate = GPIO_AF7_EVENTOUT;
  HAL_GPIO_Init(INT_GPIO_Port, &GPIO_InitStruct);

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

  /*Configure GPIO pins : HALL_Pin CLOSE_Pin */
  GPIO_InitStruct.Pin = HALL_Pin|CLOSE_Pin;
  GPIO_InitStruct.Mode = GPIO_MODE_ANALOG;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);

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

  /*Configure GPIO pins : SWT1_Pin SWT2_Pin */
  GPIO_InitStruct.Pin = SWT1_Pin|SWT2_Pin;
  GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);

  /*Configure GPIO pins : COL1_Pin KP_C2_Pin KP_C3_Pin KP_C4_Pin */
  GPIO_InitStruct.Pin = COL1_Pin|KP_C2_Pin|KP_C3_Pin|KP_C4_Pin;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_OD;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
  HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);

  /*Configure GPIO pin : COL2_Pin */
  GPIO_InitStruct.Pin = COL2_Pin;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_OD;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
  HAL_GPIO_Init(COL2_GPIO_Port, &GPIO_InitStruct);

  /*Configure GPIO pins : SWT3_Pin SWT4_Pin */
  GPIO_InitStruct.Pin = SWT3_Pin|SWT4_Pin;
  GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  HAL_GPIO_Init(GPIOC, &GPIO_InitStruct);

  /*Configure GPIO pins : ROW1_Pin ROW2_Pin ROW3_Pin */
  GPIO_InitStruct.Pin = ROW1_Pin|ROW2_Pin|ROW3_Pin;
  GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
  GPIO_InitStruct.Pull = GPIO_PULLUP;
  HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

  /*Configure GPIO pins : ROW4_Pin TOUCH_Pin */
  GPIO_InitStruct.Pin = ROW4_Pin|TOUCH_Pin;
  GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  HAL_GPIO_Init(GPIOD, &GPIO_InitStruct);

  /*Configure GPIO pins : COL3_Pin KP_C1_Pin */
  GPIO_InitStruct.Pin = COL3_Pin|KP_C1_Pin;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_OD;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
  HAL_GPIO_Init(GPIOD, &GPIO_InitStruct);

  /*Configure GPIO pins : KP_R1_Pin KP_R2_Pin KP_R3_Pin KP_R4_Pin */
  GPIO_InitStruct.Pin = KP_R1_Pin|KP_R2_Pin|KP_R3_Pin|KP_R4_Pin;
  GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
  GPIO_InitStruct.Pull = GPIO_PULLUP;
  HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);

/* USER CODE BEGIN MX_GPIO_Init_2 */
/* USER CODE END MX_GPIO_Init_2 */
}

/* USER CODE BEGIN 4 */
PUTCHAR_PROTOTYPE
{
  /* Place your implementation of fputc here */
  /* e.g. write a character to the USART1 and Loop until the end of transmission */
  HAL_UART_Transmit(&huart2, (uint8_t *)&ch, 1, 0xFFFF);

  return ch;
}

void HAL_I2C_ListenCpltCallback(I2C_HandleTypeDef *hi2c)
{
	i2c_register = 0;
	HAL_I2C_EnableListen_IT(hi2c);
}

void HAL_I2C_AddrCallback(I2C_HandleTypeDef *hi2c, uint8_t TransferDirection, uint16_t AddrMatchCode) {
	if (TransferDirection == I2C_DIRECTION_TRANSMIT) {
		HAL_I2C_Slave_Seq_Receive_IT(hi2c, &i2c_register, 1, I2C_NEXT_FRAME);
	} else {
		send_register();
	}
}

uint8_t send_data[2];
void send_register(void) {
	switch (i2c_register) {
	case I2C_REGISTER_DELTA:
		HAL_I2C_Slave_Seq_Transmit_IT(&hi2c1, &delta, 1, I2C_NEXT_FRAME);
		break;

	case I2C_REGISTER_KEYPAD:
		send_data[0] = keypad_state & 0xFF;
		send_data[1] = keypad_state >> 8;
		HAL_I2C_Slave_Seq_Transmit_IT(&hi2c1, &send_data, 2, I2C_NEXT_FRAME);
		delta &= ~(1 << DELTA_KP_BIT);
		break;

	case I2C_REGISTER_BUTTON:
		send_data[0] = button_state & 0xFF;
		send_data[1] = button_state >> 8;
		HAL_I2C_Slave_Seq_Transmit_IT(&hi2c1, &send_data, 2, I2C_NEXT_FRAME);
		delta &= ~(1 << DELTA_BTN_BIT);
		break;

	case I2C_REGISTER_RFID_PRESENT:
		HAL_I2C_Slave_Seq_Transmit_IT(&hi2c1, &card_present, 1, I2C_NEXT_FRAME);
		delta &= ~(1 << DELTA_CARD_PRESENT_BIT);
		break;
	case I2C_REGISTER_RFID_ID:
		HAL_I2C_Slave_Seq_Transmit_IT(&hi2c1, card_id, 4, I2C_NEXT_FRAME);
		delta &= ~(1 << DELTA_CARD_ID_BIT);
		break;
	default:
		break;
	}
}

void HAL_I2C_SlaveRxCpltCallback(I2C_HandleTypeDef *hi2c)
{
}

void HAL_I2C_SlaveTxCpltCallback(I2C_HandleTypeDef *hi2c)
{
}

void scan_keypad(void)
{
  uint16_t new_keypad_state = 0;

	HAL_GPIO_WritePin(KP_C1_GPIO_Port, KP_C1_Pin, GPIO_PIN_RESET);
	keypad_state |= (HAL_GPIO_ReadPin(KP_R1_GPIO_Port, KP_R1_Pin) == GPIO_PIN_RESET) << 0;
	keypad_state |= (HAL_GPIO_ReadPin(KP_R2_GPIO_Port, KP_R2_Pin) == GPIO_PIN_RESET) << 1;
	keypad_state |= (HAL_GPIO_ReadPin(KP_R3_GPIO_Port, KP_R3_Pin) == GPIO_PIN_RESET) << 2;
	keypad_state |= (HAL_GPIO_ReadPin(KP_R4_GPIO_Port, KP_R4_Pin) == GPIO_PIN_RESET) << 3;
	HAL_GPIO_WritePin(KP_C1_GPIO_Port, KP_C1_Pin, GPIO_PIN_SET);

	HAL_GPIO_WritePin(KP_C2_GPIO_Port, KP_C2_Pin, GPIO_PIN_RESET);
	keypad_state |= (HAL_GPIO_ReadPin(KP_R1_GPIO_Port, KP_R1_Pin) == GPIO_PIN_RESET) << 4;
	keypad_state |= (HAL_GPIO_ReadPin(KP_R2_GPIO_Port, KP_R2_Pin) == GPIO_PIN_RESET) << 5;
	keypad_state |= (HAL_GPIO_ReadPin(KP_R3_GPIO_Port, KP_R3_Pin) == GPIO_PIN_RESET) << 6;
	keypad_state |= (HAL_GPIO_ReadPin(KP_R4_GPIO_Port, KP_R4_Pin) == GPIO_PIN_RESET) << 7;
	HAL_GPIO_WritePin(KP_C2_GPIO_Port, KP_C2_Pin, GPIO_PIN_SET);

	HAL_GPIO_WritePin(KP_C3_GPIO_Port, KP_C3_Pin, GPIO_PIN_RESET);
	keypad_state |= (HAL_GPIO_ReadPin(KP_R1_GPIO_Port, KP_R1_Pin) == GPIO_PIN_RESET) << 8;
	keypad_state |= (HAL_GPIO_ReadPin(KP_R2_GPIO_Port, KP_R2_Pin) == GPIO_PIN_RESET) << 9;
	keypad_state |= (HAL_GPIO_ReadPin(KP_R3_GPIO_Port, KP_R3_Pin) == GPIO_PIN_RESET) << 10;
	keypad_state |= (HAL_GPIO_ReadPin(KP_R4_GPIO_Port, KP_R4_Pin) == GPIO_PIN_RESET) << 11;
	HAL_GPIO_WritePin(KP_C3_GPIO_Port, KP_C3_Pin, GPIO_PIN_SET);

	HAL_GPIO_WritePin(KP_C4_GPIO_Port, KP_C4_Pin, GPIO_PIN_RESET);
	keypad_state |= (HAL_GPIO_ReadPin(KP_R1_GPIO_Port, KP_R1_Pin) == GPIO_PIN_RESET) << 12;
	keypad_state |= (HAL_GPIO_ReadPin(KP_R2_GPIO_Port, KP_R2_Pin) == GPIO_PIN_RESET) << 13;
	keypad_state |= (HAL_GPIO_ReadPin(KP_R3_GPIO_Port, KP_R3_Pin) == GPIO_PIN_RESET) << 14;
	keypad_state |= (HAL_GPIO_ReadPin(KP_R4_GPIO_Port, KP_R4_Pin) == GPIO_PIN_RESET) << 15;
	HAL_GPIO_WritePin(KP_C4_GPIO_Port, KP_C4_Pin, GPIO_PIN_SET);

  old_keypad_state = keypad_state;
	keypad_state = new_keypad_state;
	if (keypad_state != old_keypad_state) {
		delta |= 1 << DELTA_KP_BIT;
	}
}

void scan_buttons(void)
{
  uint16_t new_button_state = 0;

	HAL_GPIO_WritePin(COL1_GPIO_Port, COL1_Pin, GPIO_PIN_SET);
	button_state |= (HAL_GPIO_ReadPin(ROW1_GPIO_Port, ROW1_Pin) == GPIO_PIN_RESET) << 0;
	button_state |= (HAL_GPIO_ReadPin(ROW2_GPIO_Port, ROW2_Pin) == GPIO_PIN_RESET) << 1;
	button_state |= (HAL_GPIO_ReadPin(ROW3_GPIO_Port, ROW3_Pin) == GPIO_PIN_RESET) << 2;
	button_state |= (HAL_GPIO_ReadPin(ROW4_GPIO_Port, ROW4_Pin) == GPIO_PIN_RESET) << 3;
	HAL_GPIO_WritePin(COL1_GPIO_Port, COL1_Pin, GPIO_PIN_RESET);

	HAL_GPIO_WritePin(COL2_GPIO_Port, COL2_Pin, GPIO_PIN_SET);
	button_state |= (HAL_GPIO_ReadPin(ROW1_GPIO_Port, ROW1_Pin) == GPIO_PIN_RESET) << 4;
	button_state |= (HAL_GPIO_ReadPin(ROW2_GPIO_Port, ROW2_Pin) == GPIO_PIN_RESET) << 5;
	button_state |= (HAL_GPIO_ReadPin(ROW3_GPIO_Port, ROW3_Pin) == GPIO_PIN_RESET) << 6;
	button_state |= (HAL_GPIO_ReadPin(ROW4_GPIO_Port, ROW4_Pin) == GPIO_PIN_RESET) << 7;
	HAL_GPIO_WritePin(COL2_GPIO_Port, COL2_Pin, GPIO_PIN_RESET);

	HAL_GPIO_WritePin(COL3_GPIO_Port, COL3_Pin, GPIO_PIN_SET);
	button_state |= (HAL_GPIO_ReadPin(ROW1_GPIO_Port, ROW1_Pin) == GPIO_PIN_RESET) << 8;
	button_state |= (HAL_GPIO_ReadPin(ROW2_GPIO_Port, ROW2_Pin) == GPIO_PIN_RESET) << 9;
	button_state |= (HAL_GPIO_ReadPin(ROW3_GPIO_Port, ROW3_Pin) == GPIO_PIN_RESET) << 10;
	button_state |= (HAL_GPIO_ReadPin(ROW4_GPIO_Port, ROW4_Pin) == GPIO_PIN_RESET) << 11;
	HAL_GPIO_WritePin(COL3_GPIO_Port, COL3_Pin, GPIO_PIN_RESET);

	// TODO: read the touch sensors here too!

  old_button_state = button_state;
  button_state = new_button_state;
	if (button_state != old_button_state) {
		delta |= 1 << DELTA_KP_BIT;
	}
}

void rfid_check_card() {
	old_card_present = card_present;
	for (int i = 0; i < CARD_ID_LEN; i++) {
		old_card_id[i] = card_id[i];
	}

	card_present = rc522_checkCard(card_id);

	// set delta
	if (old_card_present != card_present) {
		delta |= 1 << DELTA_CARD_PRESENT_BIT;
	}
	for (int i = 0; i < CARD_ID_LEN; i++) {
		if (old_card_id[i] != card_id[i]) {
			delta |= 1 << DELTA_CARD_ID_BIT;
			break;
		}
	}
}

void send_iterupt(void)
{
  if (delta != old_delta) {
    old_delta = delta;
	  HAL_GPIO_WritePin(INT_GPIO_Port, INT_Pin, delta != 0);
  }
}
/* 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 */