---

一、硬件电路

通过TIMER3的通道3提供PWM驱动电机

二、舵机初始化

初始化让舵机位于最左边，也就是0°。

static int ServoInit(struct Servo *ptdev){
	if(NULL == ptdev){
		LogDebug("ServoInit EINVAL \r\n");
		return -EINVAL;
	}
	int ret = ServoDevPwm.Config(&ServoDevPwm,SET_PERIOD_VALUE,20000000);
	if(ret != ESUCCESS){
		LogDebug("ServoDev.Config EIO \r\n");
		return -EIO;
	}
	
	ret = ServoDevPwm.Config(&ServoDevPwm,SET_COMPARE_VALUE,500000);
	if(ret != ESUCCESS){
		LogDebug("ServoDev.Config EIO \r\n");
		return -EIO;
	}
	return ESUCCESS;
}

在本文中
舵机0°时 PWM周期为20ms 占空时间为0.5ms
舵机45°时 PWM周期为20ms 占空时间为1ms
舵机90°时 PWM周期为20ms 占空时间为1.5ms
舵机180°时 PWM周期为20ms 占空时间为2ms

三、舵机控制

static int ServoSetAngle(struct Servo *ptdev,uint8_t angle){
	if(NULL == ptdev || angle > 180){
		LogDebug("ServoSetAngle EINVAL \r\n");
		return -EINVAL;
	}

	uint32_t compare = 500000 + angle*500000/45;
	int ret = ServoDevPwm.Config(&ServoDevPwm,SET_COMPARE_VALUE,compare);
	if(ret != ESUCCESS){
		LogDebug("ServoDev.Config EIO \r\n");
		return -EIO;
	}
	
	return ESUCCESS;
}