STM32 extended key scan

First , Look at the schematic

 

Corresponding ADC2 The passage of 13

Take longer to sample

 

Code

adc_key.c

#include "adc_key.h"

#define BTN_BUFF_LEN 50

uint32_t Get_ADC2(void)
{
	uint32_t adc_value;
	HAL_ADC_Start(&hadc2);
	if(HAL_ADC_PollForConversion(&hadc2,10) == HAL_OK)
	{
		adc_value = HAL_ADC_GetValue(&hadc2);
	}
	return adc_value;
}

uint16_t Read_Btn(void)
{
	uint16_t tmp;
	uint8_t i = 0, j = 0;
	uint16_t btn_buf[BTN_BUFF_LEN];
	for(i = 0; i < BTN_BUFF_LEN; i++)
	{
		btn_buf[i] = Get_ADC2();
	}
	
	for(i = 0; i <= BTN_BUFF_LEN/2; i++)
	{
		for(j = 0; j < BTN_BUFF_LEN - i - 1;j++)
		{
			if(btn_buf[j+1] < btn_buf[j])
			{
				tmp = btn_buf[j+1];
				btn_buf[j+1] = btn_buf[j];
				btn_buf[j] = tmp;
			}
		}
	}
	
	if(BTN_BUFF_LEN % 2 == 0)
	{
		return ((btn_buf[BTN_BUFF_LEN/2-1] + btn_buf[BTN_BUFF_LEN/2])/2);
	}
	
	else
	{
		return (btn_buf[BTN_BUFF_LEN/2]);
	}
}


uint8_t Scan_Key(void)
{
	uint16_t btn_tmp = 0;
	btn_tmp = Read_Btn();
	
	if(btn_tmp < 0x0fff / 14)
		return 1;
	
	else if((btn_tmp > 0x0fff/14)&&(btn_tmp < 0x0fff/14*3))
		return 2;
	
	else if((btn_tmp > 0x0fff/14*3)&&(btn_tmp < 0x0fff/14*5))
		return 3;
	
	else if((btn_tmp > 0x0fff/14*5)&&(btn_tmp < 0x0fff/14*7))
		return 4;
	
	else if((btn_tmp > 0x0fff/14*7)&&(btn_tmp < 0x0fff/14*9))
		return 5;
	
	else if((btn_tmp > 0x0fff/14*9)&&(btn_tmp < 0x0fff/14*11))
		return 6;
	
	else if((btn_tmp > 0x0fff/14*11)&&(btn_tmp < 0x0fff/14*13))
		return 7;

	else if((btn_tmp > 0x0fff/14*13)&&(btn_tmp <0x0f6f))
		return 8;
	else
	{
		return 0;
	}
}

 adc_key.h

#include "main.h"
#include "adc.h"

uint32_t Get_ADC2(void);
uint16_t Read_Btn(void);
uint8_t Scan_Key(void);

 main.c

/* USER CODE BEGIN Header */
/**
  ******************************************************************************
  * @file           : main.c
  * @brief          : Main program body
  ******************************************************************************
  * @attention
  *
  * <h2><center>&copy; Copyright (c) 2022 STMicroelectronics.
  * All rights reserved.</center></h2>
  *
  * This software component is licensed by ST under BSD 3-Clause license,
  * the "License"; You may not use this file except in compliance with the
  * License. You may obtain a copy of the License at:
  *                        opensource.org/licenses/BSD-3-Clause
  *
  ******************************************************************************
  */
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "adc.h"
#include "gpio.h"

/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include "adc_key.h"
#include "lcd.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 ---------------------------------------------------------*/

/* USER CODE BEGIN PV */
__IO uint32_t lcd_uwTick;
uint8_t lcd_string[64] = {0};
// Key variables 
uint8_t ucKey_Val,ucKey_Down,ucKey_Up,ucKey_Old;
__IO uint32_t key_uwTick = 0; // control key_proc() Execution speed of 

/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
/* USER CODE BEGIN PFP */

/* USER CODE END PFP */

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

void LedDisp(uint8_t dsLED)
{
	HAL_GPIO_WritePin(GPIOC,GPIO_PIN_13|GPIO_PIN_14|GPIO_PIN_15|GPIO_PIN_8
                   |GPIO_PIN_9|GPIO_PIN_10|GPIO_PIN_11|GPIO_PIN_12,GPIO_PIN_SET);
	// Extinguish all LED The lamp 
	HAL_GPIO_WritePin(GPIOD,GPIO_PIN_2,GPIO_PIN_SET);
	HAL_GPIO_WritePin(GPIOD,GPIO_PIN_2,GPIO_PIN_RESET);
	
	HAL_GPIO_WritePin(GPIOC,dsLED<<8,GPIO_PIN_RESET);
	HAL_GPIO_WritePin(GPIOD,GPIO_PIN_2,GPIO_PIN_SET);
	HAL_GPIO_WritePin(GPIOD,GPIO_PIN_2,GPIO_PIN_RESET);
}

void Lcd_Proc()
{
	if(uwTick - lcd_uwTick < 200)
		return;
	lcd_uwTick = uwTick;
	
//	sprintf((char *)lcd_string,"%5.3fV",Get_ADC2()*3.3/4096);
//	LCD_DisplayStringLine(Line1,lcd_string);
	
	sprintf((char *)lcd_string,"%04X,%1d",Get_ADC2(),(uint32_t)Scan_Key());
	LCD_DisplayStringLine(Line2,lcd_string);
}

void key_proc()
{
	if(uwTick - key_uwTick < 50) 
		return;
	key_uwTick = uwTick;
	
	ucKey_Val = Scan_Key();
	ucKey_Down = ucKey_Val & (ucKey_Old ^ ucKey_Val);
	ucKey_Up = ~ucKey_Val & (ucKey_Old ^ ucKey_Val);
	ucKey_Old = ucKey_Val;
	switch(ucKey_Down)
	{
		case 1: LedDisp(0X01); break;
		case 2: LedDisp(0X02); break;
		case 3: LedDisp(0XFF); break;
		case 4: LedDisp(0X00); break;
		case 5: break;
		case 6: break;
		case 7: break;
		case 8: break;
		default: 
			break;
	}
	
}

/* 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_ADC2_Init();
  /* USER CODE BEGIN 2 */
	LCD_Init();
	LCD_Clear(White);
  /* USER CODE END 2 */

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {
    /* USER CODE END WHILE */

    /* USER CODE BEGIN 3 */
		Lcd_Proc();
		key_proc();
  }
  /* USER CODE END 3 */
}