STM32F103和RC522模块通信，为什么M1卡无回应？

Question

从网上下载的代码例程，可以正确运行，运行，硬件方面没问题，但我根据需要作出修改后，就无法读卡了。
源程序是如下连线

/*******************************
1--SS <----->PF0 //普通GPIO
*2--SCK <----->PB13
*3--MOSI<----->PB15
*4--MISO<----->PB14
*5--IRQ 悬空
*6--GND <----->GND
*7--RST <----->PF1 //普通GPIO
*8--VCC <----->VCC
***********************************/

我修改成了

/*******************************
1--SS <----->PB12 //SPI的NSS口
*2--SCK <----->PB13
*3--MOSI<----->PB15
*4--MISO<----->PB14
*5--IRQ 悬空
*6--GND <----->GND
*7--RST <----->PA8 //普通GPIO
*8--VCC <----->VCC
***********************************/
初始化配置下
void SPI2_Init(void)

{

GPIO_InitTypeDef GPIO_InitStructure;

SPI_InitTypeDef SPI_InitStructure;
RCC_APB2PeriphClockCmd( RCC_APB2Periph_GPIOB|RCC_APB2Periph_GPIOA, ENABLE );
RCC_APB1PeriphClockCmd( RCC_APB1Periph_SPI2, ENABLE );

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8;    //PA8 -> RST

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

GPIO_Init(GPIOA, &GPIO_InitStructure);

GPIO_ResetBits(GPIOA,GPIO_Pin_8);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_13 | GPIO_Pin_14 | GPIO_Pin_15;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; 
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOB, &GPIO_InitStructure);
GPIO_SetBits(GPIOB,GPIO_Pin_13|GPIO_Pin_14|GPIO_Pin_15);

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_Low;      
SPI_InitStructure.SPI_CPHA = SPI_CPHA_1Edge;    
SPI_InitStructure.SPI_NSS = SPI_NSS_Soft;       
SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_256;        SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;
SPI_InitStructure.SPI_CRCPolynomial = 7;    
SPI_Init(SPI2, &SPI_InitStructure);  
SPI_Cmd(SPI2, ENABLE); 

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_12;   //PB12 -> SS

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

GPIO_Init(GPIOB, &GPIO_InitStructure);

GPIO_SetBits(GPIOB,GPIO_Pin_12);

}

下面是我修改的位操作
#define SET_SPI_CS (GPIOB->BSRR = 0X1000) //PB12 -> 1
#define CLR_SPI_CS (GPIOB->BRR = 0X1000) //PB12 -> 0

#define SET_RC522RST GPIOA->BSRR = 0X0100 //PA8 -> 1
#define CLR_RC522RST GPIOA->BRR = 0X0100 //PA8 -> 0

不知道我这么修改可不可以，反正M1卡就是不理我

Answer 1

根据芯片手册，您宏定义这块应该修改成下面这样吧：

#define SET_SPI_CS (GPIOB->BSRR |= 1<<12)  //PB12 -> 1
#define CLR_SPI_CS (GPIOB->BRR  |= 1<<12)  //PB12 -> 0
#define SET_RC522RST GPIOA->BSRR  |= 1<<8） //PA8 -> 1
#define CLR_RC522RST GPIOA->BRR  |= 1<<8） //PA8 -> 0

用移位做好些，操作本位时不影响其他位！