采用的是例程（FullDuplex_HardNSS）中的初始化：
void SPI_FullDuplex_Init(void)
{
GPIO_InitTypeDef GPIO_InitStructure={0};
SPI_InitTypeDef SPI_InitStructure={0};
RCC_APB2PeriphClockCmd( RCC_APB2Periph_GPIOA | RCC_APB2Periph_SPI1, ENABLE );
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init( GPIOA, &GPIO_InitStructure );
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init( GPIOA, &GPIO_InitStructure );
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
GPIO_Init( GPIOA, &GPIO_InitStructure );
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init( GPIOA, &GPIO_InitStructure );
SPI_SSOutputCmd( SPI1, 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_Low;
SPI_InitStructure.SPI_CPHA = SPI_CPHA_2Edge;
SPI_InitStructure.SPI_NSS = SPI_NSS_Hard;
SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_32;
SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;
SPI_InitStructure.SPI_CRCPolynomial = 7;
SPI_Init( SPI1, &SPI_InitStructure );
SPI_Cmd( SPI1, ENABLE );
}
main函数中的代码如下：
int main(void) {
//优先级分组，延时以及调试串口初始化（使用的是USART3->D8(TX)、D9(RX) ,需要用别的串口的同学可以修改USART_Printf_Init()中的参数
LQ_V30xInit();
PIN_InitConfig(PC4, GPI, 0, GPIO_Mode_IN_FLOATING);
SPI_FullDuplex_Init();
u8 i=0;
u8 TxData[18] = { 0x41, 0x42, 0x43, 0x44, 0x45, 0x46,
0x47, 0x48, 0x49, 0x50, 0x51, 0x52,
0x53, 0x54, 0x55, 0x56, 0x57, 0x58 };
//检测是否达到发送数据的要求
while(GPIO_ReadInputDataBit(GPIOC,GPIO_Pin_4) == Bit_RESET)
{
LED_Ctrl(LED1, OFF);
}
LED_Ctrl(LED1, ON);
while(1)
{
for(i = 0; i < 18; i++)
{
while( SPI_I2S_GetFlagStatus( SPI1, SPI_I2S_FLAG_TXE ) == RESET );
SPI_I2S_SendData( SPI1, TxData[i] );
}
LED_Ctrl(LED0, RVS);
Delay_Ms(100);
}
}
得到的波形如下图：只有前几个数据是正常的，当NSS引脚出现高电平时数据解析出现问题，我的从设备收到的数据为乱码。
并且看mian函数中我发送的是18个数据，这里明显不到18个数据。发送完成后NSS引脚也没有自动拉高，顺便说一下，NSS引脚接了10K的上拉电阻。
热门产品 :
CH32X035: 32位USB+USB PD单片机
