STM32 steering gear controller

        This section will introduce you to stm32 SCM to do a steering controller , By rotating the potentiometer , To control the output angle of the steering gear .

        Old rules , Let's share the source code project with you ,

        Pay attention to WeChat public number ： Guangyi electronics （dlrcclub）, Reply key ： Steering gear tester .

        Before talking about the source code, let's review the control principle of the steering gear , At frequency 50hz Next , Give me a 0.5ms-2.5ms Duty cycle of pulse width , You can perform a test on the steering gear 45°-180° The rotation of .

How can we realize it through the single chip computer ？

1、 To configure ADC modular , Collect analog quantity of potentiometer , Change the collected data into pwm The duty cycle to be output .

2、 To configure PWM modular , Generate a frequency 50Hz, Pulse width at 1ms-2.0ms The square wave .

      1ms-2.0ms The corresponding angle is 45°-135°.

3、 Range conversion function . The data range collected by the potentiometer is 0-4096, And ours PWM The range of values required by the capture function is 1000-2000. therefore , Need to put 0-4096 The value range of is converted to 1000-2000.

         Let's enumerate the functions of each part ,ADC and PWM All from atoms stm32 Routine , You can also extract from the routine directly .

ADC.c, adc Some basic configurations .

 #include "adc.h"
 #include "delay.h"
	   
//³õʼ»¯ADC
//ÕâÀïÎÒÃǽöÒÔ¹æÔòͨµÀΪÀý
//ÎÒÃÇĬÈϽ«¿ªÆôͨµÀ0~3																	   
void  Adc_Init(void)
{ 	
	ADC_InitTypeDef ADC_InitStructure; 
	GPIO_InitTypeDef GPIO_InitStructure;

	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA |RCC_APB2Periph_ADC1	, ENABLE );	  //ʹÄÜADC1ͨµÀʱÖÓ
 

	RCC_ADCCLKConfig(RCC_PCLK2_Div6);   //ÉèÖÃADC·ÖƵÒò×Ó6 72M/6=12,ADC×î´óʱ¼ä²»Äܳ¬¹ý14M

	//PA1 ×÷ΪģÄâͨµÀÊäÈëÒý½Å                         
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1;
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN;		//Ä£ÄâÊäÈëÒý½Å
	GPIO_Init(GPIOA, &GPIO_InitStructure);	

	ADC_DeInit(ADC1);  //¸´Î»ADC1,½«ÍâÉè ADC1 µÄÈ«²¿¼Ä´æÆ÷ÖØÉèΪȱʡֵ  ADC1 ADC2 ADC3 

	ADC_InitStructure.ADC_Mode = ADC_Mode_Independent;	//ADC¹¤×÷ģʽ:ADC1ºÍADC2¹¤×÷ÔÚ¶ÀÁ¢Ä£Ê½
	ADC_InitStructure.ADC_ScanConvMode = DISABLE;	//Ä£Êýת»»¹¤×÷ÔÚµ¥Í¨µÀģʽ
	ADC_InitStructure.ADC_ContinuousConvMode = DISABLE;	//Ä£Êýת»»¹¤×÷ÔÚµ¥´Îת»»Ä£Ê½
	ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_None;	//ת»»ÓÉÈí¼þ¶ø²»ÊÇÍⲿ´¥·¢Æô¶¯
	ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;	//ADCÊý¾ÝÓÒ¶ÔÆë
	ADC_InitStructure.ADC_NbrOfChannel = 1;	//˳Ðò½øÐйæÔòת»»µÄADCͨµÀµÄÊýÄ¿
	ADC_Init(ADC1, &ADC_InitStructure);	//¸ù¾ÝADC_InitStructÖÐÖ¸¶¨µÄ²ÎÊý³õʼ»¯ÍâÉèADCxµÄ¼Ä´æÆ÷   

  
	ADC_Cmd(ADC1, ENABLE);	//ʹÄÜÖ¸¶¨µÄADC1
	
	ADC_ResetCalibration(ADC1);	//ʹÄܸ´Î»Ð£×¼  
	 
	while(ADC_GetResetCalibrationStatus(ADC1));	//µÈ´ý¸´Î»Ð£×¼½áÊø
	
	ADC_StartCalibration(ADC1);	 //¿ªÆôADУ׼
 
	while(ADC_GetCalibrationStatus(ADC1));	 //µÈ´ýУ׼½áÊø
 
//	ADC_SoftwareStartConvCmd(ADC1, ENABLE);		//ʹÄÜÖ¸¶¨µÄADC1µÄÈí¼þת»»Æô¶¯¹¦ÄÜ

}				  
//»ñµÃADCÖµ
//ch:ͨµÀÖµ 0~3
u16 Get_Adc(u8 ch)   
{
  	//ÉèÖÃÖ¸¶¨ADCµÄ¹æÔò×éͨµÀ£¬Ò»¸öÐòÁУ¬²ÉÑùʱ¼ä     PB1¶ÔÓ¦ADC9
	ADC_RegularChannelConfig(ADC1, ch, 1, ADC_SampleTime_239Cycles5 );	//ADC1,ADCͨµÀ,²ÉÑùʱ¼äΪ239.5ÖÜÆÚ	  			    
  
	ADC_SoftwareStartConvCmd(ADC1, ENABLE);		//ʹÄÜÖ¸¶¨µÄADC1µÄÈí¼þת»»Æô¶¯¹¦ÄÜ	
	 
	while(!ADC_GetFlagStatus(ADC1, ADC_FLAG_EOC ));//µÈ´ýת»»½áÊø

	return ADC_GetConversionValue(ADC1);	//·µ»Ø×î½üÒ»´ÎADC1¹æÔò×éµÄת»»½á¹û
}

u16 Get_Adc_Average(u8 ch,u8 times)
{
	u32 temp_val=0;
	u8 t;
	for(t=0;t<times;t++)
	{
		temp_val+=Get_Adc(ch);
		delay_ms(5);
	}
	return temp_val/times;
} 	 

PWM.c,PWM Part of the basic configuration .

#include "pwm.h"



//PWMÊä³ö³õʼ»¯
//arr£º×Ô¶¯ÖØ×°Öµ
//psc£ºÊ±ÖÓÔ¤·ÖƵÊý
void TIM1_PWM_Init(u16 arr,u16 psc)
{  
	 GPIO_InitTypeDef GPIO_InitStructure;
	TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
	TIM_OCInitTypeDef  TIM_OCInitStructure;

	RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE);// 
 	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA , ENABLE);  //ʹÄÜGPIOÍâÉèʱÖÓʹÄÜ
	                                                                     	

   //ÉèÖøÃÒý½ÅΪ¸´ÓÃÊä³ö¹¦ÄÜ,Êä³öTIM1 CH1µÄPWMÂö³å²¨ÐÎ
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8; //TIM_CH1
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;  //¸´ÓÃÍÆÍìÊä³ö
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
	GPIO_Init(GPIOA, &GPIO_InitStructure);

	
	TIM_TimeBaseStructure.TIM_Period = arr; //ÉèÖÃÔÚÏÂÒ»¸ö¸üÐÂʼþ×°Èë»î¶¯µÄ×Ô¶¯ÖØ×°ÔؼĴæÆ÷ÖÜÆÚµÄÖµ	 80K
	TIM_TimeBaseStructure.TIM_Prescaler =psc; //ÉèÖÃÓÃÀ´×÷ΪTIMxʱÖÓƵÂʳýÊýµÄÔ¤·ÖƵֵ  ²»·ÖƵ
	TIM_TimeBaseStructure.TIM_ClockDivision = 0; //ÉèÖÃʱÖÓ·Ö¸î:TDTS = Tck_tim
	TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;  //TIMÏòÉϼÆÊýģʽ
	TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure); //¸ù¾ÝTIM_TimeBaseInitStructÖÐÖ¸¶¨µÄ²ÎÊý³õʼ»¯TIMxµÄʱ¼ä»ùÊýµ¥Î»

 
	TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2; //Ñ¡Ôñ¶¨Ê±Æ÷ģʽ:TIMÂö³å¿í¶Èµ÷ÖÆģʽ2
	TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //±È½ÏÊä³öʹÄÜ
	TIM_OCInitStructure.TIM_Pulse = 0; //ÉèÖôý×°È벶»ñ±È½Ï¼Ä´æÆ÷µÄÂö³åÖµ
	TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; //Êä³ö¼«ÐÔ:TIMÊä³ö±È½Ï¼«ÐÔ¸ß
	TIM_OC1Init(TIM1, &TIM_OCInitStructure);  //¸ù¾ÝTIM_OCInitStructÖÐÖ¸¶¨µÄ²ÎÊý³õʼ»¯ÍâÉèTIMx

  TIM_CtrlPWMOutputs(TIM1,ENABLE);	//MOE Ö÷Êä³öʹÄÜ	

	TIM_OC1PreloadConfig(TIM1, TIM_OCPreload_Enable);  //CH1ԤװÔØʹÄÜ	 
	
	TIM_ARRPreloadConfig(TIM1, ENABLE); //ʹÄÜTIMxÔÚARRÉϵÄԤװÔؼĴæÆ÷
	
	TIM_Cmd(TIM1, ENABLE);  //ʹÄÜTIM1
 
   
}

         Range conversion function , Personally, I think this function is the focus of the whole project , I hope you can remember this function , This function is taken from arduino The function in , Remember and you can use it skillfully . 

float map(float value,float fromLow,float fromHigh,float toLow,float toHigh)
{
	return ((value-fromLow)*(toHigh-toLow)/(fromHigh-fromLow)+toLow);
}

The main function main.c

 int main(void)
 {	
	u16 pwmval_adc=0;    
	 
	u16 pwmval_to_range;
	
	
	//u8 adc_value;
	delay_init();	    	                      					//ÑÓʱº¯Êý³õʼ»¯	  
	TIM1_PWM_Init(1999,719);                  					//Fre_PWM = 72000/(719+1)/(1999+1)=50hz
	uart_init(9600);                          
  Adc_Init();

	printf("this is a test");
  while(1)
	{
		//	printf("this is a test");
 		delay_ms(10);	 
		pwmval_adc = Get_Adc_Average(ADC_Channel_1,10);           //adcx Ϊ»ñÈ¡µ½ ADCµÄÖµ
		//printf("adc_value= %d \n\r",pwmval_adc);                     //´òÓ¡³öADC ²É¼¯µ½µÄµçλÆ÷Öµ   4090
		
		pwmval_to_range = (int)map(pwmval_adc,0,4092,1000,2000);
		delay_ms(100);
		printf("range =%d\t\r\n",pwmval_to_range);                           //Êä³ö ÔÚ1000-2000·¶Î§ÄÚתÍ귶ΧµÄADC Öµ
		
		TIM_SetCompare1(TIM1,pwmval_to_range);
		
	} 
}

         Download the program , We can see that the steering gear follows 45°-135° To move back and forth .

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