我对lm3s6965例程里的pwm例程把PD1改PE1,结果PE1输出低电平,而没改之前PD1输出对应的是喇叭,高电平有效,一下是原厂提供的程序
#include "inc/hw_memmap.h"
#include "inc/hw_types.h"
#include "driverlib/debug.h"
#include "driverlib/gpio.h"
#include "driverlib/pwm.h"
#include "driverlib/sysctl.h"
#include "drivers/rit128x96x4.h"
//*****************************************************************************
//
// The error routine that is called if the driver library encounters an error.
//
//*****************************************************************************
#ifdef DEBUG
void
__error__(char *pcFilename, unsigned long ulLine)
{
}
#endif
//*****************************************************************************
//
// This example demonstrates how to setup the PWM block to generate signals.
//
//*****************************************************************************
int
main(void)
{
unsigned long ulPeriod;
//
// Set the clocking to run directly from the crystal.
//
SysCtlClockSet(SYSCTL_SYSDIV_1 | SYSCTL_USE_OSC | SYSCTL_OSC_MAIN |
SYSCTL_XTAL_8MHZ);
SysCtlPWMClockSet(SYSCTL_PWMDIV_1);
//
// Initialize the OLED display.
//
RIT128x96x4Init(1000000);
//
// Clear the screen and tell the user what is happening.
//
RIT128x96x4StringDraw("Generating PWM", 18, 24, 15);
RIT128x96x4StringDraw("on PF0 and PD1", 18, 32, 15);
//
// Enable the peripherals used by this example.
//
SysCtlPeripheralEnable(SYSCTL_PERIPH_PWM);
SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOD);
SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOF);
//
// Set GPIO F0 and D1 as PWM pins. They are used to output the PWM0 and
// PWM1 signals.
//
GPIOPinTypePWM(GPIO_PORTF_BASE, GPIO_PIN_0);
GPIOPinTypePWM(GPIO_PORTD_BASE, GPIO_PIN_1);
//
// Compute the PWM period based on the system clock.
//
ulPeriod = SysCtlClockGet() / 440;
//
// Set the PWM period to 440 (A) Hz.
//
PWMGenConfigure(PWM_BASE, PWM_GEN_0,
PWM_GEN_MODE_UP_DOWN | PWM_GEN_MODE_NO_SYNC);
PWMGenPeriodSet(PWM_BASE, PWM_GEN_0, ulPeriod);
//
// Set PWM0 to a duty cycle of 25% and PWM1 to a duty cycle of 75%.
//
PWMPulseWidthSet(PWM_BASE, PWM_OUT_0, ulPeriod / 4);
PWMPulseWidthSet(PWM_BASE, PWM_OUT_1, ulPeriod * 3 / 4);
//
// Enable the PWM0 and PWM1 output signals.
//
PWMOutputState(PWM_BASE, PWM_OUT_0_BIT | PWM_OUT_1_BIT, true);
//
// Enable the PWM generator.
//
PWMGenEnable(PWM_BASE, PWM_GEN_0);
//
// Loop forever while the PWM signals are generated.
//
while(1)
{
}
}
我只把上面程序中的GPIOD改为GPIOE,结果PE1输出低电平,把PWM_OUT_1改为PWM_OUT_5也是低电平,(注:PE1对应的是pwm5),希望各位高手给小弟解答啊。我对这个程序不了解,拜托了,详细点
此帖出自
小平头技术问答
一周热门 更多>