我使用这个arduino库初始化&与我的MFRC522芯片通信,库最初采用SPI接口与单片机之间通信;RC522。当我在SPI接口中使用它时,一切都OK &正确操作。现在我正在尝试将接口更改为UART模式。基于NXP的MFRC522数据表,我设置了UART模式的引脚状态。也阅读&编写序列&UART帧地址基于数据表。此外,当我读取RC522的VersionReg寄存器时,它成功地返回了0x92,这意味着它是V 2.0,但它无法检测到RFID标签的存在。SPI和SPI之间还有其他区别吗?UART接口或任何我必须做的额外设置?有没有人在UART模式下使用这个芯片的经验?
我的改变寄存器读&写功能:
unsigned char ReadRawRC(unsigned char Address)
{
unsigned char ucAddr;
unsigned char ucResult=0;
ucAddr = Address | 0x80;
UART_SendBlocking(USART0, &ucAddr, 1);
UART_ReadBlocking(USART0, &ucResult, 1);
return ucResult;
}
/////////////////////////////////////////////////////////////////////
//@ Function: write RC522 register
//@ Parameter Description: Address [IN]: register address
//Value [IN]: write value
/////////////////////////////////////////////////////////////////////
void WriteRawRC(unsigned char Address, unsigned char value)
{
unsigned char ucAddr;
unsigned char ucValu;
ucAddr = Address & 0x7F;
ucValu = value;
UART_SendBlocking(USART0, &ucAddr, 1);
UART_SendBlocking(USART0, &ucValu, 1);
}
问题是关于UART模式和SPI模式下地址字节的差异,如图所示图片新修改的读/写函数运行得非常好:
unsigned char ucAddr;
unsigned char ucValu;
uint8_t IncomingData;
/////////////////////////////////////////////////////////////////////
//@ Function: Reading RC522 register
//@ Parameter Description: Address [IN]: register address
//@ Return: The value read
/////////////////////////////////////////////////////////////////////
unsigned char ReadRawRC(unsigned char Address)
{
ucAddr = Address | 0x80;
dataSign=false;
Chip_UART_SendBlocking(LPC_USART0, &ucAddr, 1);
StopWatch_DelayMs(3);
if(dataSign==true)
return IncomingData;
return 0;
}
/////////////////////////////////////////////////////////////////////
//@ Function: write RC522 register
//@ Parameter Description: Address [IN]: register address
//Value [IN]: write value
/////////////////////////////////////////////////////////////////////
void WriteRawRC(unsigned char Address, unsigned char value)
{
ucAddr = Address & 0x7F;
ucValu = value;
Chip_UART_SendBlocking(LPC_USART0, &ucAddr, 1);
Chip_UART_SendBlocking(LPC_USART0, &value, 1);
}