标签:style blog http color io ar 2014 art div
下面直接上代码:
#include "lpc177x_8x.h" #include "lpc177x_8x_clkpwr.h" #include "lpc177x_8x_gpio.h" #include "debug_frmwrk.h" #include "led.h" volatile uint32_t cycleCounter; void DelayMs(uint32_t delay) { uint32_t startTime = cycleCounter; while ((uint32_t)(cycleCounter - startTime) <= delay); } void SysTick_Handler(void) //SysTick handler sub-routine (1ms) { cycleCounter++; } uint32_t a[8]={0xFF8FFFFF,0xFFCFFFFF,0xFF4FFFFF,0xFF6FFFFF,0xFF2FFFFF,0xFF3FFFFF,0xFF1FFFFF,0xFF9FFFFF}; int main(void) { SysTick_Config(CLKPWR_GetCLK(CLKPWR_CLKTYPE_CPU) / 1000); GPIO_Init();//ʹÄÜGPIO¿ÚµÄʱÖÓ GPIO_SetDir(4,1<<20, GPIO_DIRECTION_OUTPUT); GPIO_SetDir(4,1<<21, GPIO_DIRECTION_OUTPUT); GPIO_SetDir(4,1<<22, GPIO_DIRECTION_OUTPUT); GPIO_SetDir(4,1<<23, GPIO_DIRECTION_OUTPUT); while(1) { GPIO_SetValue(4, a[0]); DelayMs(1); GPIO_ClearValue(4,0xFFFFFFFF); GPIO_SetValue(4, a[1]); DelayMs(1); GPIO_ClearValue(4,0xFFFFFFFF); GPIO_SetValue(4, a[2]); DelayMs(1); GPIO_ClearValue(4,0xFFFFFFFF); GPIO_SetValue(4, a[3]); DelayMs(1); GPIO_ClearValue(4,0xFFFFFFFF); GPIO_SetValue(4, a[4]); DelayMs(1); GPIO_ClearValue(4,0xFFFFFFFF); GPIO_SetValue(4, a[5]); DelayMs(1); GPIO_ClearValue(4,0xFFFFFFFF); GPIO_SetValue(4, a[6]); DelayMs(1); GPIO_ClearValue(4,0xFFFFFFFF); GPIO_SetValue(4, a[7]); DelayMs(1); GPIO_ClearValue(4,0xFFFFFFFF); } }
其中GPIO_ClearValue(4,0xFFFFFFFF);这句代码非常重要。 因为如果有些位不清零的话,下次setvalue某些位为0是不行的,setvalue只能设置1.
标签:style blog http color io ar 2014 art div
原文地址:http://www.cnblogs.com/yibanshouxi/p/3964770.html