Blue Bridge Cup embedded Hal library ADC

The experiment purpose

adopt LCD Display the voltage value , And by rotating R37 Change the voltage value

ADC Related knowledge

STM32 HAL Library Learning Series No 1 piece ADC To configure And DAC To configure

Hardware design

Schematic diagram

STM32CubeMX To configure

1、 Pin selection PB15 Measure the voltage

2、 Clock source selection HSE

3、 Set the clock frequency . stay HCLK Place input 80 enter

4、 To configure ADC Corresponding GPIO Pin . Only aliases are added here R37

5、 choose ADC2 The passage of 15 Measure the voltage .

6、ADC Parameter configuration . The clock prescaler coefficient is set to “2 Asynchronous clock mode of frequency division ” , Others use the default configuration .

7、 Set the project name 、 Select compile software

8、 Only reference the required library files ; Generate separate .c and .h file .

9、 The generated code

Keil To configure

1、 add to LCD Related documents . Provide the match point resource package fonts.h and lcd.h Added to the new project Inc In the folder
route ：D:\MX_project\ADC2\Core\Inc

Provide the match point resource package lcd.c Added to the new project Src In the folder
route ：D:\MX_project\ADC2\Core\Src

2、 Downloader selection and related configuration

software design

1、main.c Add header file to .（ notes : Put all the code in BEGIN and END Between , Prevent overwriting the original code when regenerating the code ）

#include "stdio.h"
#include "string.h"
#include "lcd.h"

2、 obtain ADC Function of voltage value

uint16_t getADC(void)
{
    
	uint16_t adc = 0;
	
	HAL_ADC_Start(&hadc2); // Polling mode , It needs to be opened continuously in the cycle 
	adc = HAL_ADC_GetValue(&hadc2); // Read ADC Value 
	
	return adc;
}

3、 Define a character array to store voltage values

	char buf[20];

4、LCD Initialization and other processing （ Want to know more about LCD, Please have a look at LCD piece ）

	LCD_Init();
	LCD_Clear(Blue);
	LCD_SetBackColor(Blue);
	LCD_SetTextColor(White);
	
	LCD_DisplayStringLine(Line0, (uint8_t *)" ");
	LCD_DisplayStringLine(Line1, (uint8_t *)" ");
	LCD_DisplayStringLine(Line2, (uint8_t *)" ADC Test ");
	LCD_DisplayStringLine(Line3, (uint8_t *)" ");
	LCD_DisplayStringLine(Line4, (uint8_t *)" ");
	
	LCD_SetBackColor(White);
	LCD_SetTextColor(Blue);

	LCD_DisplayStringLine(Line5, (uint8_t *)" ");
	LCD_DisplayStringLine(Line6, (uint8_t *)" ADC2 CH15 ");
	LCD_DisplayStringLine(Line7, (uint8_t *)" ");
	LCD_DisplayStringLine(Line8, (uint8_t *)" ");
	LCD_DisplayStringLine(Line9, (uint8_t *)" ");

5、 Poll to read the voltage value , And display the voltage value to LCD On
ADC use 12 Bit resolution ,2^12=4096
Voltage max ：3.3V
Obtained voltage value *3.3/4096 = Decimal voltage value

		LCD_SetTextColor(Red);
		sprintf(buf, " VAL:%.2fV", getADC()*3.3/4096);
		HAL_Delay(100);
		LCD_DisplayStringLine(Line8, (uint8_t *)buf);	

compile 、 erase 、 download

1、 Compiler Engineering

Compile successfully

2、 Erase program

Erase succeeded

3、 Download program

perhaps

Download successful

Function position

ADC

HAL_StatusTypeDef       HAL_ADC_Start(ADC_HandleTypeDef *hadc);
uint32_t                HAL_ADC_GetValue(ADC_HandleTypeDef *hadc);

ADC initialization

static void MX_ADC2_Init(void)
{
    
  ADC_ChannelConfTypeDef sConfig = {
    0};
  /** Common config */
  hadc2.Instance = ADC2;
  hadc2.Init.ClockPrescaler = ADC_CLOCK_ASYNC_DIV1; // The clock frequency division  //1 frequency division ,ADCCLK=PCLK2/1=
  hadc2.Init.Resolution = ADC_RESOLUTION_12B; //ADC The resolution of the ,12 Bit mode 
  hadc2.Init.DataAlign = ADC_DATAALIGN_RIGHT; // Right alignment , low 12 It works 
  hadc2.Init.GainCompensation = 0;
  hadc2.Init.ScanConvMode = ADC_SCAN_DISABLE; // Turn off scan mode , That is, single channel is effective 
  hadc2.Init.EOCSelection = ADC_EOC_SINGLE_CONV; 
  hadc2.Init.LowPowerAutoWait = DISABLE;
  hadc2.Init.ContinuousConvMode = DISABLE;  // Single conversion mode , Turn off continuous conversion 
  hadc2.Init.NbrOfConversion = 1; // The number of channels is 1
  hadc2.Init.DiscontinuousConvMode = DISABLE; // Prohibit discontinuous sampling mode 
  hadc2.Init.ExternalTrigConv = ADC_SOFTWARE_START;  //  Software triggers 
  hadc2.Init.ExternalTrigConvEdge = ADC_EXTERNALTRIGCONVEDGE_NONE; // Use software to trigger 
  hadc2.Init.DMAContinuousRequests = DISABLE; // close DMA request 
  hadc2.Init.Overrun = ADC_OVR_DATA_PRESERVED;
  hadc2.Init.OversamplingMode = DISABLE;
  if (HAL_ADC_Init(&hadc2) != HAL_OK)
  {
    
    Error_Handler();
  }
  /** Configure Regular Channel */
  sConfig.Channel = ADC_CHANNEL_15;
  sConfig.Rank = ADC_REGULAR_RANK_1;
  sConfig.SamplingTime = ADC_SAMPLETIME_640CYCLES_5;
  sConfig.SingleDiff = ADC_SINGLE_ENDED;
  sConfig.OffsetNumber = ADC_OFFSET_NONE;
  sConfig.Offset = 0;
  if (HAL_ADC_ConfigChannel(&hadc2, &sConfig) != HAL_OK)
  {
    
    Error_Handler();
  }
}

LCD

void LCD_Init(void);
void LCD_SetTextColor(vu16 Color);
void LCD_SetBackColor(vu16 Color);
void LCD_Clear(u16 Color);
void LCD_DisplayStringLine(u8 Line, u8 *ptr);

Experimental phenomena

By spinning R37 The potentiometer can change the voltage

problem

The maximum voltage is only 3.23V. I don't know whether it's an error or something . If you know the reason, please advise .

Blue Bridge Cup -HAL library -TIM_BASE