stm32单片机 操控l9110h电机 analogWrite处总报错，为啥

#include "led.h"
#include "delay.h"
#include "sys.h"
#include "exti.h"
#include "key.h"
#include "usart.h"
#include "timer.h"
//*************************************************************************************
//°´¼ü´®¿ÚÖ÷º¯Êý
//from SUOAO
//Author£ºxl
//*************************************************************************************


int main(void)
{	
	delay_init();	    	 //ÑÓʱº¯Êý³õʼ»¯	
	NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);// ÉèÖÃÖжÏÓÅÏȼ¶·Ö×é2
	uart_init(9600);  //´®¿Ú³õʼ»¯Îª9600
	LED_Init();		  	 //³õʼ»¯ÓëLEDÁ¬½ÓµÄÓ²¼þ½Ó¿Ú 
	KEY_Init();
	int n =0;
while(1)
	{u8 damn=KEY_Scan(1);
		
		if(damn==KEY1_PRES)
if(damn==KEY1_PRES){
 delay_ms(20);
if(damn==KEY1_PRES){
n=n+50;
if(n>255){n=5;}
}
 while(damn==KEY1_PRES){;}}
 analogWrite(5,n);
 analogWrite(6,0); }

最后两行报错，怎么解决？

main.c(34): warning:  #223-D: function "analogWrite" declared implicitly
   analogWrite(5,n);
main.c(35): warning:  #1-D: last line of file ends without a newline
   analogWrite(6,0); }

main.c(35): warning:  #1-D: last line of file ends without a newline
   analogWrite(6,0); }

上面这个是因为少一个 }    在后面加一个}

main.c(34): warning:  #223-D: function "analogWrite" declared implicitly
   analogWrite(5,n);

这个是因为函数未声明，int main前面的行加上extern analogWrite(int,int);