Stm32f103c8t6 PWM drive steering gear (sg90)

Little knowledge ： Same timer , Different channel outputs different outputs PWM Characteristics .

For different channel outputs of the same timer PWM, Because they share a counter , therefore frequency It has to be the same , and Duty cycle By their own CCR decision , It can be set separately . also , phase Due to counter update , all PWM Will jump at the same time , So the phase is synchronous .

If you use 1 A timer controls multiple steering gears or DC motors , Use different channels of the same timer PWM, That's fine .

	TIM_OC1Init(TIM2,&TIM_OCInitStructure);
	TIM_OC2Init(TIM2,&TIM_OCInitStructure);
	TIM_OC3Init(TIM2,&TIM_OCInitStructure);
	TIM_OC4Init(TIM2,&TIM_OCInitStructure);

Code ：

PWM.h

#ifndef __PWM_H
#define __PWM_H

void PWM_Init();
void PWM_SetCompare2(uint16_t Compare);

#endif

PWM.c

#include "stm32f10x.h" // Device header

void PWM_Init()
{
    
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2,ENABLE);  // Turn on timer 2
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA,ENABLE);// passageway 2 Clock enable function 
	

	GPIO_InitTypeDef GPIO_InitStructure; 				// Definition GPIO Initializing structure variables 
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;	// Set up GPIO For push-pull output mode 
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1;			
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;	// The speed is set to  50MHz
	GPIO_Init(GPIOA, &GPIO_InitStructure);				// Proceed according to the above parameters  GPIO The initialization 
	
	TIM_InternalClockConfig(TIM2);//TIM The time base unit of is controlled by the internal clock 
	
	TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;
	TIM_TimeBaseInitStructure.TIM_ClockDivision = TIM_CKD_DIV1;
	TIM_TimeBaseInitStructure.TIM_CounterMode = TIM_CounterMode_Up;
	TIM_TimeBaseInitStructure.TIM_Period = 20000 - 1; //ARR  The value of the automatic reloader 
	TIM_TimeBaseInitStructure.TIM_Prescaler = 72 - 1; //PSC  Prescaler value   Yes 72M（720000000） Conduct  7200 frequency division   namely 10K At different frequencies   meter 10000 Number  1s Time for 
	TIM_TimeBaseInitStructure.TIM_RepetitionCounter = 0;// Repeat counter value 
	TIM_TimeBaseInit(TIM2,&TIM_TimeBaseInitStructure); 
	 	
	TIM_OCInitTypeDef TIM_OCInitStructure;
	TIM_OCStructInit(&TIM_OCInitStructure);
	TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
	TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;// Output polarity selection 
	TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;// Output status enable 
	TIM_OCInitStructure.TIM_Pulse = 0;//CCR, That is, the duty cycle is  10%
	TIM_OC2Init(TIM2,&TIM_OCInitStructure);
	
	TIM_Cmd(TIM2,ENABLE);
}


void PWM_SetCompare2(uint16_t Compare)
{
    
	TIM_SetCompare2(TIM2, Compare);
}

Serco.h

#ifndef __Servo_H
#define __Servo_H

void Servo_Init(void);
void Servo_SetAngle(float Angle);

#endif

Servo.c

#include "stm32f10x.h" // Device header
#include "PWM.H"

void Servo_Init(void)
{
    
	PWM_Init();
}

void Servo_SetAngle(float Angle)
{
    
	PWM_SetCompare2(Angle / 180 * 2000 +500);
}

main.c

#include "stm32f10x.h" // Device header
#include "Delay.h"
#include "LED.h"
#include "Key.h"
#include "OLED.H"
#include "Servo.H"

uint8_t KeyNum;
float Angle; // Steering angle  

int main(void)
{
    
	OLED_Init();
	Servo_Init();
	Key_Init();
	
	OLED_ShowString(1,1,"Angle:");
	
	while (1)
	{
    
		
		KeyNum = Key_GetNum();
		if(KeyNum == 1)
		{
    
			Angle +=30;
			if(Angle > 180)
			{
    
				Angle = 0;
			}
		}
		Servo_SetAngle(Angle);
		OLED_ShowNum(1,7,Angle,3);// Show the angle on the screen 

	}
}

What happened ：

Changed a steering gear , Then use the oscilloscope to measure that the pin is Wave Of , But the steering gear is Immobility . Later it was found that voltage Not enough .

Work hard , Grow slowly