STM32 控制74HC595 驱动点阵 文字能移动

遇到了很奇怪的问题，程序明明没错但就是不显示，最后把在main函数中定义的变量count移动到main 外面就正常了 。仿真后发现，在main 函数中定义的局部变量 初始值不为0 ，超出控制范围 ， 导致程序跑飞。按理说keil 定义变量默认初始化为0才对 。最后将定义count初始化为0，程序正常运行。下次定义变量一定要初始化啊！！！

在单步调试中，发现这个问题。不得不说一下，keil 在线仿真非常好用。

#include<stm32f10x.h>#include<intrins.h>void spi2Init(void);void gpioInit(void);void delay(unsigned int i);void DisplayOnLattice(unsigned char a,unsigned char b,unsigned char c,unsigned char d );unsigned char table[]={0x80,0x00,0x40,0x00,0x20,0x00,0x10,0x00,0x08,0x00,0x04,0x00,0x02,0x00,0x01,0x00,0x00,0x80,0x00,0x40,0x00,0x20,0x00,0x10,0x00,0x08,0x00,0x04,0x00,0x02,0x00,0x01};static unsigned char bb[]={0x01,0x00,0x01,0x00,0x01,0xF0,0x1F,0x80,0x05,0x40,0x09,0x30,0x11,0xCE,0x26,0x40,0x00,0x80,0x01,0xFC,0x7F,0x00,0x00,0x80,0x00,0x80,0x02,0x80,0x01,0x00,0x00,0x00};

//static unsigned char aa[]={0x80,0x00,0x40,0x00,0x20,0x00,0x10,0x00,0x08,0x00,0x04,0x00,0x02,0x00,0x01,0x00,0x00,0x80,0x00,0x40,0x00,0x20,0x00,0x10,0x00,0x08,0x00,0x04,0x00,0x02,0x00,0x01};static unsigned char cc[]={0x01,0xC0,0x07,0x00,0x01,0xF8,0x1F,0x08,0x21,0x40,0x29,0x00,0x01,0x60,0x0C,0x20,0x14,0xC0,0x1C,0x60,0x11,0xA0,0x1C,0x40,0x10,0xA0,0x1B,0x18,0x10,0x0E,0x00,0x00};unsigned char dd[]={0};unsigned char *pointer[]={bb,cc};/* 在这里 用到了指针数组pointer ,*(pointer[0])指向数组bb的首个元素地址*(pointer[1])指向数组cc的首个元素地址上面字库定义时 bb和cc两个数组是连在一起的，所以下面可以连续滚动多个字unsigned char *pointer[]={bb,cc};也可以定义成unsigned char *pointer[]={bb};程序也能正常运行。若把定义aa数组的注释去掉，则程序将不能显示连续滚动连续的两个汉字的功能：*/ int main(){  unsigned char i=0,count=0; //count 没有初始化导致错误  unsigned int time=0;  gpioInit();spi2Init();while(1){for(time=0;time<1000;time++)        //不行for(i=0;i<32;i+=2)DisplayOnLattice(~(*(pointer[0]+i+1+count)),~(*(pointer[0]+i+count)),table[i+1],table[i]);  count+=2;if(count==17*2)count=0; }}void DisplayOnLattice(unsigned char a,unsigned char b,unsigned char c,unsigned char d ){GPIO_WriteBit(GPIOB,GPIO_Pin_12,Bit_RESET);SPI_I2S_SendData(SPI2,a);while(SPI_I2S_GetFlagStatus(SPI2,SPI_I2S_FLAG_TXE)==0);SPI_I2S_ClearFlag(SPI2,SPI_I2S_FLAG_TXE);SPI_I2S_SendData(SPI2,b);while(SPI_I2S_GetFlagStatus(SPI2,SPI_I2S_FLAG_TXE)==0);SPI_I2S_ClearFlag(SPI2,SPI_I2S_FLAG_TXE);SPI_I2S_SendData(SPI2,c);while(SPI_I2S_GetFlagStatus(SPI2,SPI_I2S_FLAG_TXE)==0);SPI_I2S_ClearFlag(SPI2,SPI_I2S_FLAG_TXE);SPI_I2S_SendData(SPI2,d);while(SPI_I2S_GetFlagStatus(SPI2,SPI_I2S_FLAG_TXE)==0);SPI_I2S_ClearFlag(SPI2,SPI_I2S_FLAG_TXE);delay(1);GPIO_WriteBit(GPIOB,GPIO_Pin_12,Bit_SET);GPIO_WriteBit(GPIOB,GPIO_Pin_12,Bit_RESET);}void spi2Init(){SPI_InitTypeDef SPI_InitStructure;RCC_APB1PeriphClockCmd(RCC_APB1Periph_SPI2, ENABLE);  SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;  SPI_InitStructure.SPI_Mode = SPI_Mode_Master;  SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b;  SPI_InitStructure.SPI_CPOL = SPI_CPOL_High ;  SPI_InitStructure.SPI_CPHA = SPI_CPHA_2Edge;  SPI_InitStructure.SPI_NSS = SPI_NSS_Soft;  SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_4;  SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_LSB;    //most significant bit 最高有效位 看具体取模方式  SPI_InitStructure.SPI_CRCPolynomial = 0;  SPI_Init(SPI2, &SPI_InitStructure);SPI_Cmd(SPI2, ENABLE);}void gpioInit(void){GPIO_InitTypeDef gpio;RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB , ENABLE);gpio.GPIO_Pin=GPIO_Pin_12;             //CS   作为74hc595 RCLK  并行输出 上升沿有效gpio.GPIO_Speed=GPIO_Speed_50MHz;gpio.GPIO_Mode = GPIO_Mode_Out_PP;GPIO_Init(GPIOB, &gpio);gpio.GPIO_Pin=GPIO_Pin_13;              //SCK作为74hc595 SRCLK  串行输入时钟gpio.GPIO_Speed=GPIO_Speed_50MHz;gpio.GPIO_Mode = GPIO_Mode_AF_PP;GPIO_Init(GPIOB, &gpio);gpio.GPIO_Pin=GPIO_Pin_14;             //MISO 空闲gpio.GPIO_Speed=GPIO_Speed_50MHz;gpio.GPIO_Mode = GPIO_Mode_AF_PP;GPIO_Init(GPIOB, &gpio);gpio.GPIO_Pin=GPIO_Pin_15;              //MOSI 作为74hc595 DATA线gpio.GPIO_Speed=GPIO_Speed_50MHz;gpio.GPIO_Mode = GPIO_Mode_AF_PP;GPIO_Init(GPIOB, &gpio);}void delay(unsigned int i){int j;for(j=0;j<1000;j++)for(;i>0; i--);}