[mw_shl_code=c,true]u8 SPI1_ReadWriteByte(u8 TxData) { u8 retry=0; while(SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_TXE) == RESET)//等待发送区空 { retry++; if(retry>200) return 1; //wrong } SPI_I2S_SendData(SPI1, TxData); //通过外设SPIx发送一个数据 retry=0; while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_RXNE) == RESET) //检查指定的SPI标志位设置与否:接受缓存非空标志位 { retry++; if(retry>200) return 1; } return SPI_I2S_ReceiveData(SPI1); //返回通过SPIx最近接收的数据 }[/mw_shl_code]
[mw_shl_code=c,true] //write 4 register starting at address 01H(CONFIG1) CS_LOW; spi_buffer[0] = 0x41; // spi_buffer[1] = 0x03; spi_buffer[2] = 0x96; //CONFIG1, 250SPS spi_buffer[3] = 0xc0; //CONFIG2 spi_buffer[4] = 0xe0; //CONFIG3 spi_buffer[5] = 0x00; //LOFF for(i=0;i<6;i++) { while(SPI1_ReadWriteByte(spi_buffer) == 1); } CS_HIGH; //Read from 4 registers, starting at 0x01 //0x96, 0xC0, 0xE0, 0x00, //Global Settings across Channels 01h-04h(4) CS_LOW; spi_buffer[0] = 0x21; spi_buffer[1] = 0x03; for(i=0;i<2;i++) { while(SPI1_ReadWriteByte(spi_buffer) == 1); } for(i=0;i<4;i++) { reg = SPI1_ReadWriteByte(Dummy_Byte); } for(i=0;i<4;i++) printf(" reg[%02x] = 0x%02x ",i,reg); CS_HIGH;[/mw_shl_code] 如代码，采用例程里的SPI1_ReadWriteByte()函数，首先往四个寄存器里写值，然后直接读取寄存器的值。可是结果不对，可能是什么原因呢？