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  

#include  

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};  

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//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--);  

}