STC12LE608AD如何用PWM1输出LED半亮状态？
+5V通过限流电阻接LED到P3.5脚，我想通过这个脚输出PWM来达到LED的半亮效果。参照例程的设置和思路还是不行。请各位大虾指点下。谢谢！例程如下：/*------------------------------------------------------------------*/
/* --- STC MCU Limited ---------------------------------------------*/
/* --- STC12C56xx Series MCU PCA module output PWM wave Demo -------*/
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/* If you want to use the program or the program referenced in the*/
/* article, please specify in which data and procedures from STC */
/*------------------------------------------------------------------*/
#include "reg51.h"
#include "intrins.h"
#define FOSC 11059200L
typedef unsigned char BYTE;
typedef unsigned int WORD;
/*Declare SFR associated with the PCA */
sfr CCON = 0xD8; //PCA control register
sbit CCF0 = CCON^0; //PCA module-0 interrupt flag
sbit CCF1 = CCON^1; //PCA module-1 interrupt flag
sbit CR = CCON^6; //PCA timer run control bit
sbit CF = CCON^7; //PCA timer overflow flag
sfr CMOD = 0xD9; //PCA mode register
sfr CL = 0xE9; //PCA base timer LOW
sfr CH = 0xF9; //PCA base timer HIGH
sfr CCAPM0 = 0xDA; //PCA module-0 mode register
sfr CCAP0L = 0xEA; //PCA module-0 capture register LOW
sfr CCAP0H = 0xFA; //PCA module-0 capture register HIGH
sfr CCAPM1 = 0xDB; //PCA module-1 mode register
sfr CCAP1L = 0xEB; //PCA module-1 capture register LOW
sfr CCAP1H = 0xFB; //PCA module-1 capture register HIGH
sfr CCAPM2 = 0xDC; //PCA module-2 mode register
sfr CCAP2L = 0xEC; //PCA module-2 capture register LOW
sfr CCAP2H = 0xFC; //PCA module-2 capture register HIGH
sfr CCAPM3 = 0xDD; //PCA module-3 mode register
sfr CCAP3L = 0xED; //PCA module-3 capture register LOW
sfr CCAP3H = 0xFD; //PCA module-3 capture register HIGH
sfr PCAPWM0 = 0xF2;
sfr PCAPWM1 = 0xF3;
sfr PCAPWM2 = 0xF4;
sfr PCAPWM3 = 0xF5;
void main()
{
CCON = 0; //Initial PCA control register
//PCA timer stop running
//Clear CF flag
//Clear all module interrupt flag
CL = 0; //Reset PCA base timer
CH = 0;
CMOD = 0x02; //Set PCA timer clock source as Fosc/2
//Disable PCA timer overflow interrupt
CCAP0H = CCAP0L = 0x80; //PWM0 port output 50% duty cycle square wave
CCAPM0 = 0x42; //PCA module-0 work in 8-bit PWM mode and no PCA interrupt
CCAP1H = CCAP1L = 0xff; //PWM1 port output 0% duty cycle square wave
PCAPWM1 = 0x03;
CCAPM1 = 0x42; //PCA module-1 work in 8-bit PWM mode and no PCA interrupt
CR = 1; //PCA timer start run
while (1);
}
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