index are changing with the voltage apply to the adc

/**
  ******************************************************************************
  * @file           : main.c
  * @brief          : Main program body
  ******************************************************************************
  ** This notice applies to any and all portions of this file
  * that are not between comment pairs USER CODE BEGIN and
  * USER CODE END. Other portions of this file, whether
  * inserted by the user or by software development tools
  * are owned by their respective copyright owners.
  *
  * COPYRIGHT(c) 2020 STMicroelectronics
  *
  * Redistribution and use in source and binary forms, with or without modification,
  * are permitted provided that the following conditions are met:
  *   1. Redistributions of source code must retain the above copyright notice,
  *      this list of conditions and the following disclaimer.
  *   2. Redistributions in binary form must reproduce the above copyright notice,
  *      this list of conditions and the following disclaimer in the documentation
  *      and/or other materials provided with the distribution.
  *   3. Neither the name of STMicroelectronics nor the names of its contributors
  *      may be used to endorse or promote products derived from this software
  *      without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  ******************************************************************************
  */
/* Includes ------------------------------------------------------------------*/
#define ARM_MATH_CM4
#include "main.h"
#include "stm32f4xx_hal.h"

/* USER CODE BEGIN Includes */
#include "16x2LCD_4bits.h"
#include "mcp3911.h"
#include "dwt_stm32_delay.h"
#include "stm32f4xx_it.h"
#include "arm_math.h"
#include "core_cm4.h"
#include "calculation.h"
#include "arm_const_structs.h "


//#define Buf_Length	300
/* USER CODE END Includes */

/* Private variables ---------------------------------------------------------*/
SPI_HandleTypeDef hspi1;
DMA_HandleTypeDef hdma_spi1_rx;
arm_rfft_fast_instance_f32	fft_handler;
//arm_cfft_radix4_instance_f32 S;    /* ARM CFFT module */
//arm_cfft_instance_f32 fft_handler1;
//const static arm_cfft_instance_f32 *s;
//arm_cfft_instance_f32 varInstCfftF32;
//#define Samples 64
#define Buf_Length		4096	//2^N or fft size
#define Samples (Buf_Length/2)
/* USER CODE BEGIN PV */
/* Private variables ---------------------------------------------------------*/

/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_DMA_Init(void);
static void MX_SPI1_Init(void);
void Do_FFT(void);
/* USER CODE BEGIN PFP */
/* Private function prototypes -----------------------------------------------*/

/* USER CODE END PFP */

/* USER CODE BEGIN 0 */
volatile	uint32_t Ch1Result;
volatile	uint32_t Ch2Result;	
volatile float Ch2_Voltage;
uint32_t Temp_Result;
uint32_t Temp_Result1;
uint8_t Power_on_cofig;
uint32_t Temp_Result2;
volatile uint32_t	BCDByte[10];
uint16_t Rx_DMA_Byte_Array[Buf_Length];
float32_t FFT_Input_Array[Buf_Length]={'\0'};
float32_t FFT_Input_Array_1[Buf_Length]={'\0'};
float32_t FFT_Output_Array[Buf_Length];
uint16_t FFT_Result_Array[10]={'\0'};
float32_t FFT_Result_Index[Buf_Length]={'\0'};
float32_t Max_Frequency;
uint16_t Max_Frequency_1;
uint32_t Max_Frequency_Index;
volatile float32_t sampleFreq = 4096/Buf_Length ;
float32_t freq;
float32_t freq_1;
uint16_t	RMSValue;
int j,Result_Flag=0, Result_Update=0;
unsigned char	Print_Array[10]={'\0'};
/* USER CODE END 0 */

/**
  * @brief  The application entry point.
  *
  * @retval None
  */
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();
	HAL_Delay(10);
	DWT_Delay_Init();
	HAL_Delay(10);
  MX_DMA_Init();	
  MX_SPI1_Init();
  /* USER CODE BEGIN 2 */
//	HAL_DMA_Init(&hdma_spi1_rx);
	HAL_Delay(10);
	LCD_Initialisation();	
//	LCD_Command_Data(0x0c,0);				//display on,curser off
	HAL_Delay(10);
	LCD_String((unsigned char*)"FFT_On",1,0);
	HAL_Delay(1500);
	MCP3911_CS_LOW();
	HAL_Delay(10);	
	HAL_GPIO_WritePin(SPI1_nRESET_GPIO_Port, SPI1_nRESET_Pin, GPIO_PIN_RESET);	//RESET pin of adc low
	HAL_Delay(100);
	HAL_GPIO_WritePin(SPI1_nRESET_GPIO_Port, SPI1_nRESET_Pin, GPIO_PIN_SET);	//RESET pin of adc high
	HAL_Delay(20);
	MCP3911_CS_HIGH();
	HAL_Delay(20);
	Mcp3911Init();
	HAL_Delay(10);
//	HAL_Delay(1000);

//	LCD_Clear_Display();	
//	HAL_Delay(1500);
//	LCD_String((unsigned char*)"DMA_FFT",1,0);
	Temp_Result=Read_data_mcp3911(Mcp3911Gain,1);
//	HAL_Delay(10);
//	HextoBcd(Temp_Result);
//	Temp_Result1=Read_data_mcp3911(Mcp3911StatusCom,2);

//	Temp_Result2=Read_data_mcp3911(Mcp3911Config,2);
//	Ch1Result=Write_Address_Read_data_mcp3911(Mcp3911Ch1,2,2);	
	HAL_SPI_Receive_DMA(&hspi1,(uint8_t*) Rx_DMA_Byte_Array, (Buf_Length*2));
//		varInstCfftF32 = &arm_cfft_sR_f32_len64; 
//	s= &arm_cfft_sR_f32_len512; 
//	HAL_DMA_IRQHandler(&hdma_spi1_rx);
//	Temp_Result1=Write_Address_Read_data_mcp3911(Mcp3911StatusCom,1,2);
  /* USER CODE END 2 */

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
	
//	arm_rfft_init_f32(&fft_handler,);

  arm_rfft_fast_init_f32(&fft_handler, Buf_Length);
////		arm_cfft_radix4_init_f32(&S, Buf_Length, 0, 1);
	Ch1Result=Write_Address_Read_data_mcp3911(Mcp3911Ch1,2,2);
//		arm_cfft_init_f32(&varInstCfftF32,Samples);

  while (1)
  {

  /* USER CODE END WHILE */

  /* USER CODE BEGIN 3 */
		
		Ch1Result=Write_Address_Read_data_mcp3911(Mcp3911Ch1,2,2);
		if(Result_Flag==1	&& Result_Update==10 )
		{
			Result_Flag=0,Result_Update=0;
			Float_2_ASCII(freq_1,(char*)Print_Array,4,2,0);
			LCD_String(Print_Array,1,0);
			Float_2_ASCII(Max_Frequency,(char*)Print_Array,6,0,0);
			LCD_String(Print_Array,2,0);
			Hex2Ascii(Max_Frequency_Index,(char*)Print_Array,0,4,0,0);	
			LCD_String(Print_Array,2,7);	//
			Hex2Ascii(Rx_DMA_Byte_Array[1],(char*)Print_Array,0,6,0,0);	
			LCD_String(Print_Array,1,8);	
			Hex2Ascii(j,(char*)Print_Array,0,4,0,0);	
			LCD_String(Print_Array,2,12);	//Max_Frequency
			HAL_Delay(500);
		}
  }
  /* USER CODE END 3 */

}

/**
  * @brief System Clock Configuration
  * @retval None
  */
void SystemClock_Config(void)
{

  RCC_OscInitTypeDef RCC_OscInitStruct;
  RCC_ClkInitTypeDef RCC_ClkInitStruct;

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

  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);

    /**Initializes the CPU, AHB and APB busses clocks
    */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
  RCC_OscInitStruct.HSIState = RCC_HSI_ON;
  RCC_OscInitStruct.HSICalibrationValue = 16;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI;
  RCC_OscInitStruct.PLL.PLLM = 8;
  RCC_OscInitStruct.PLL.PLLN = 132;
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
  RCC_OscInitStruct.PLL.PLLQ = 4;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    _Error_Handler(__FILE__, __LINE__);
  }

    /**Initializes the CPU, AHB and APB busses 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_DIV4;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV2;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_4) != HAL_OK)
  {
    _Error_Handler(__FILE__, __LINE__);
  }

    /**Configure the Systick interrupt time
    */
  HAL_SYSTICK_Config(HAL_RCC_GetHCLKFreq()/1000);

    /**Configure the Systick
    */
  HAL_SYSTICK_CLKSourceConfig(SYSTICK_CLKSOURCE_HCLK);

  /* SysTick_IRQn interrupt configuration */
  HAL_NVIC_SetPriority(SysTick_IRQn, 0, 0);
}

/* SPI1 init function */
static void MX_SPI1_Init(void)
{

  /* 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_4;
  hspi1.Init.FirstBit = SPI_FIRSTBIT_MSB;
  hspi1.Init.TIMode = SPI_TIMODE_DISABLE;
  hspi1.Init.CRCCalculation = SPI_CRCCALCULATION_DISABLE;
  hspi1.Init.CRCPolynomial = 10;
  if (HAL_SPI_Init(&hspi1) != HAL_OK)
  {
    _Error_Handler(__FILE__, __LINE__);
  }

}

/**
  * Enable DMA controller clock
  */
static void MX_DMA_Init(void)
{
  /* DMA controller clock enable */
  __HAL_RCC_DMA2_CLK_ENABLE();

  /* DMA interrupt init */
  /* DMA2_Stream0_IRQn interrupt configuration */
  HAL_NVIC_SetPriority(DMA2_Stream0_IRQn, 0, 0);
  HAL_NVIC_EnableIRQ(DMA2_Stream0_IRQn);

}

/** Configure pins as
        * Analog
        * Input
        * Output
        * EVENT_OUT
        * EXTI
*/
static void MX_GPIO_Init(void)
{

  GPIO_InitTypeDef GPIO_InitStruct;

  /* GPIO Ports Clock Enable */
  __HAL_RCC_GPIOE_CLK_ENABLE();
  __HAL_RCC_GPIOC_CLK_ENABLE();
  __HAL_RCC_GPIOH_CLK_ENABLE();
  __HAL_RCC_GPIOA_CLK_ENABLE();
  __HAL_RCC_GPIOB_CLK_ENABLE();

  /*Configure GPIO pin Output Level */
  HAL_GPIO_WritePin(GPIOE, D5_LCD_Pin|D6_LCD_Pin|D7_LCD_Pin, GPIO_PIN_RESET);

  /*Configure GPIO pin Output Level */
  HAL_GPIO_WritePin(GPIOC, E_LCD_Pin|RS_LCD_Pin|D4_LCD_Pin, GPIO_PIN_RESET);

  /*Configure GPIO pin Output Level */
  HAL_GPIO_WritePin(GPIOC, SPI1_nCS_Pin|SPI1_nRESET_Pin, GPIO_PIN_SET);

  /*Configure GPIO pins : D5_LCD_Pin D6_LCD_Pin D7_LCD_Pin */
  GPIO_InitStruct.Pin = D5_LCD_Pin|D6_LCD_Pin|D7_LCD_Pin;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_OD;
  GPIO_InitStruct.Pull = GPIO_PULLUP;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
  HAL_GPIO_Init(GPIOE, &GPIO_InitStruct);

  /*Configure GPIO pins : E_LCD_Pin RS_LCD_Pin SPI1_nCS_Pin SPI1_nRESET_Pin */
  GPIO_InitStruct.Pin = E_LCD_Pin|RS_LCD_Pin|SPI1_nCS_Pin|SPI1_nRESET_Pin;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_OD;
  GPIO_InitStruct.Pull = GPIO_PULLUP;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
  HAL_GPIO_Init(GPIOC, &GPIO_InitStruct);

  /*Configure GPIO pin : D4_LCD_Pin */
  GPIO_InitStruct.Pin = D4_LCD_Pin;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
  HAL_GPIO_Init(D4_LCD_GPIO_Port, &GPIO_InitStruct);

  /*Configure GPIO pin : Dr_Input_Pin */
  GPIO_InitStruct.Pin = Dr_Input_Pin;
  GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
  GPIO_InitStruct.Pull = GPIO_PULLDOWN;
  HAL_GPIO_Init(Dr_Input_GPIO_Port, &GPIO_InitStruct);

}

/* USER CODE BEGIN 4 */

void HAL_SPI_RxCpltCallback(SPI_HandleTypeDef *hspi)
{
	uint16_t Temp_value;

	MCP3911_CS_HIGH();
	
    for(uint16_t i = 0; i < Buf_Length; i++)
    {
        Temp_value =  Rx_DMA_Byte_Array[i];
        
        FFT_Input_Array[i]=	(1 - cos(2*PI*Temp_value/Buf_Length))/2;            // Apply Windows Tech.
    
    }
    Do_FFT();

	__NOP();
}

void Do_FFT()
{

	arm_rfft_fast_f32(&fft_handler, (float32_t *)FFT_Input_Array,(float32_t *)FFT_Input_Array_1,0);


	arm_cmplx_mag_f32((float32_t *)FFT_Input_Array_1,(float32_t *) FFT_Output_Array,Samples);

	arm_abs_f32((float32_t *)FFT_Output_Array,(float32_t *)FFT_Output_Array,Samples);
	arm_max_f32(&FFT_Output_Array[1],(uint32_t)(Samples),&Max_Frequency,&Max_Frequency_Index);

	Max_Frequency_Index++;

	
/*	j=1;
	freq = FFT_Output_Array[1];
	for(uint16_t i=2;i<Samples;i++)
	{
	//for the maximum valude of spectrum magnitude
		if(FFT_Output_Array[i] > freq)
		{
            j = i;
            freq = FFT_Output_Array[i]; 
//	        Max_Frequency_1=FFT_Output_Array[j];					
		}
	}	
*/
}
/* USER CODE END 4 */

/**
  * @brief  This function is executed in case of error occurrence.
  * @param  file: The file name as string.
  * @param  line: The line in file as a number.
  * @retval None
  */
void _Error_Handler(char *file, int line)
{
  /* USER CODE BEGIN Error_Handler_Debug */
  /* User can add his own implementation to report the HAL error return state */
  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,
     tex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
  /* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */

/**
  * @}
  */

/**
  * @}
  */

/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/