怎样用M128产生50hz占空比可调的pwm波？
我调了好久了，引脚一点反应都没有，以下是我的程序，在时钟1中断里改变OCR1A，OCR1B，OCR1C的值来调节占空比，请各位帮我看看吧：unsigned charangle0_h=0x05,angle0_l=0xDC;
unsigned charangle1_h=0x05,angle1_l=0xDC;
unsigned charangle2_h=0x05,angle2_l=0xDC;
static void io_init(void)//
{
PORTA = 0x08;
DDRA= 0xFF;
PORTB = 0xFF;
DDRB= 0xFF;
PORTC = 0x00;
DDRC= 0x00;
PORTD = 0xFF;
DDRD= 0xFF;
PORTE = 0xFF;
DDRE= 0x0F;
PORTF = 0xFF;
DDRF= 0xFF;
PORTG = 0x1F;
DDRG= 0x1F;
}
///////////////////////////////////////////
//时钟初始化：
void timer1_init(void)
{ TCCR1B = 0x00; //stop
TCNT1H = 0x00; //setup
TCNT1L = 0x00;
OCR1AL = 0xDC;
OCR1AH = 0x05;//1500
OCR1BH = 0x05;
OCR1BL = 0xDC;//1500
OCR1CH = 0x05;
OCR1CL = 0xDC;//1500
ICR1H= 0x4E;
ICR1L= 0x20;//20000
TCCR1A = 0xAA;//COM1A1 COM1A0 COM1B1 COM1B0 COM1C1 COM1C0 WGM11 WGM10
//1 0 1 0 1 0 1 0
TCCR1B = 0x1A;//ICNC1 ICES1 – WGM13 WGM12 CS12 CS11 CS10
} //0 0 0 1 1 0 1 0 8分频
////////////////////////////////////////////////////////////////////////////
#pragma interrupt_handler timer1_ovf_isr:15
void timer1_ovf_isr(void)
{
OCR1AH = angle0_h;
OCR1AL = angle0_l;
OCR1BH = angle1_h;
OCR1BL = angle1_l;
OCR1CH = angle2_h;
OCR1CL = angle2_l;
}
void DeviceInit(void)
{
CLI();
io_init;
timer1_init();
TIMSK = 0x04; //timer interrupt sources
MCUCR = 0x00;
SEI();
} 对不起，今天才看到帖子。
//ICC-AVR application builder : 2008-3-8 AM 10:36:14
// Target : M8
// Crystal: 4.0000Mhz
#include <iom8v.h>
#include <macros.h>
void port_init(void)
{
PORTB = 0x00;
DDRB= 0x00;
PORTC = 0x00; //m103 output only
DDRC= 0x00;
PORTD = 0x00;
DDRD= 0x00;
}
//TIMER1 initialize - prescale:1
// WGM: 8) PWM phz freq correct, TOP=ICRn
// desired value: 50Hz
// actual value: 50.000Hz (0.0%)
void timer1_init(void)
{
TCCR1B = 0x00; //stop
TCNT1H = 0x63; //setup
TCNT1L = 0xC0;
OCR1AH = 0x9C;
OCR1AL = 0x40;
OCR1BH = 0x9C;
OCR1BL = 0x40;
ICR1H= 0x9C;
ICR1L= 0x40;
TCCR1A = 0x80;
TCCR1B = 0x11; //start Timer
}
//call this routine to initialize all peripherals
void init_devices(void)
{
//stop errant interrupts until set up
CLI(); //disable all interrupts
port_init();
timer1_init();
MCUCR = 0x00;
GICR= 0x00;
TIMSK = 0x00; //timer interrupt sources
SEI(); //re-enable interrupts
//all peripherals are now initialized
}
记得，一定要把OCR1A的端口方向设置为输出 谢谢
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