PIC24F串口接收的问题

只看该作者 · 2009-9-2 10:07

我用的PIC24F系列的单片机,8M晶振.但是使用UART时发现一个问题,就是设定完波特率,发送数据没有问题,但是接收有时候是乱码. 调试时发现串口状态位中的FREE被置位,查资料说是帧错误,但是完全不明白什么是"当期字符的帧错误". 串口工作在高速模式. 现在只有9600收发没有问题,其他波特率都有问题.

请各位指教.谢谢.

只看该作者 · 2009-9-3 09:44

完全没人知道吗? 现在怀疑是用ICD2调试的时候才有错误.

只看该作者 · 2009-9-4 14:05

我刚完成了PIC24F16KA101+MRF49XA设计的无线抄表项目，用到串口功能，好用着呢，你可以检查下硬件问题！

void ConsoleInit(void)//串口初始化
{
TRISBbits.TRISB2 = 1;
TRISBbits.TRISB7 = 0;
U1MODEbits.UARTEN = 0; // Bit15 TX, RX DISABLED, ENABLE at end of func
U1MODEbits.USIDL = 0; // Bit13 Continue in Idle
U1MODEbits.IREN = 0; // Bit12 No IR translation
U1MODEbits.RTSMD = 0; // Bit11 Simplex Mode
U1MODEbits.UEN = 0; // Bits8,9 TX,RX enabled, CTS,RTS not
U1MODEbits.WAKE = 0; // Bit7 No Wake up (since we don't sleep here)
U1MODEbits.LPBACK = 0; // Bit6 No Loop Back
U1MODEbits.ABAUD = 0; // Bit5 No Autobaud (would require sending '55')
U1MODEbits.RXINV = 0; // Bit4 IdleState = 1
U1MODEbits.BRGH = 1; // Bit3 16 clocks per bit period
U1MODEbits.PDSEL = 0; // Bits1,2 8bit, No Parity
U1MODEbits.STSEL = 0; // Bit0 One Stop Bit

U1BRG = 103; // baud rate

U1STAbits.UTXISEL1 = 0; //Bit15 Int when Char is transferred (1/2 config!)
U1STAbits.UTXINV = 0; //Bit14 N/A, IRDA config
U1STAbits.UTXISEL0 = 0; //Bit13 Other half of Bit15
U1STAbits.UTXBRK = 0; //Bit11 Disabled
U1STAbits.UTXEN = 0; //Bit10 TX pins controlled by periph
U1STAbits.UTXBF = 0; //Bit9 *Read Only Bit*
U1STAbits.TRMT = 0; //Bit8 *Read Only bit*
U1STAbits.URXISEL = 0; //Bits6,7 Int. on character recieved
U1STAbits.ADDEN = 0; //Bit5 Address Detect Disabled
U1STAbits.RIDLE = 0; //Bit4 *Read Only Bit*
U1STAbits.PERR = 0; //Bit3 *Read Only Bit*
U1STAbits.FERR = 0; //Bit2 *Read Only Bit*
U1STAbits.OERR = 0; //Bit1 *Read Only Bit*
U1STAbits.URXDA = 0; //Bit0 *Read Only Bit*
IFS0bits.U1TXIF = 0; // Clear the Transmit Interrupt Flag
IEC0bits.U1TXIE = 0; // Enable Transmit Interrupts
IFS0bits.U1RXIF = 0; // Clear the Recieve Interrupt Flag
IEC0bits.U1RXIE = 1; // Enable Recieve Interrupts
U1MODEbits.UARTEN = 1; // And turn the peripheral on
U1STAbits.UTXEN = 1;
}

void ConsolePut(BYTE c)//单字节发送
{
while( !ConsoleIsPutReady() );
U1TXREG = c;
}
void __attribute__ ((interrupt, no_auto_psv)) _U1RXInterrupt(void) //接收中断函数
{
unsigned char tmp;
tmp = U1RXREG;
if(FIFOPtr < FIFOMax)
{
RCBuffer[FIFOPtr++]=tmp;
}
IFS0bits.U1RXIF = 0;
}

只看该作者 · 2009-9-6 22:50

问题已经找出来了，是芯片的BUG。
我用的是PIC24FJ32GA002,后来查了这个系列的勘误表，发现某些批次的芯片UART，高速模式波特率计算会有问题。就是说我程序里边的波特率都给错了。无奈，只好用低速模式了。

只看该作者 · 2012-3-15 15:35

我也正在调串口，现在是中断可以发送数据，但接收数据，产生不了中断，也没有uxif标志。。不知道还有哪里要注意的呢，

配置跟这个是一样的：
void ConsoleInit(void)//串口初始化
{
TRISBbits.TRISB2 = 1;
TRISBbits.TRISB7 = 0;
      U1MODEbits.UARTEN = 0;       // Bit15 TX, RX DISABLED, ENABLE at end of func
      U1MODEbits.USIDL = 0;       // Bit13 Continue in Idle
      U1MODEbits.IREN = 0;       // Bit12 No IR translation
      U1MODEbits.RTSMD = 0;       // Bit11 Simplex Mode
      U1MODEbits.UEN = 0;             // Bits8,9 TX,RX enabled, CTS,RTS not
      U1MODEbits.WAKE = 0;       // Bit7 No Wake up (since we don't sleep here)
      U1MODEbits.LPBACK = 0;       // Bit6 No Loop Back
      U1MODEbits.ABAUD = 0;       // Bit5 No Autobaud (would require sending '55')
      U1MODEbits.RXINV = 0;       // Bit4 IdleState = 1
      U1MODEbits.BRGH = 1;       // Bit3 16 clocks per bit period
      U1MODEbits.PDSEL = 0;       // Bits1,2 8bit, No Parity
      U1MODEbits.STSEL = 0;       // Bit0 One Stop Bit

      U1BRG = 103;       // baud rate

      U1STAbits.UTXISEL1 = 0;       //Bit15 Int when Char is transferred (1/2 config!)
      U1STAbits.UTXINV = 0;       //Bit14 N/A, IRDA config
      U1STAbits.UTXISEL0 = 0;       //Bit13 Other half of Bit15
      U1STAbits.UTXBRK = 0;       //Bit11 Disabled
      U1STAbits.UTXEN = 0;       //Bit10 TX pins controlled by periph
      U1STAbits.UTXBF = 0;       //Bit9 *Read Only Bit*
      U1STAbits.TRMT = 0;             //Bit8 *Read Only bit*
      U1STAbits.URXISEL = 0;       //Bits6,7 Int. on character recieved
      U1STAbits.ADDEN = 0;       //Bit5 Address Detect Disabled
      U1STAbits.RIDLE = 0;       //Bit4 *Read Only Bit*
      U1STAbits.PERR = 0;             //Bit3 *Read Only Bit*
      U1STAbits.FERR = 0;             //Bit2 *Read Only Bit*
      U1STAbits.OERR = 0;             //Bit1 *Read Only Bit*
      U1STAbits.URXDA = 0;       //Bit0 *Read Only Bit*
      IFS0bits.U1TXIF = 0;       // Clear the Transmit Interrupt Flag
      IEC0bits.U1TXIE = 0;       // Enable Transmit Interrupts
      IFS0bits.U1RXIF = 0;       // Clear the Recieve Interrupt Flag
      IEC0bits.U1RXIE = 1;       // Enable Recieve Interrupts
      U1MODEbits.UARTEN = 1;       // And turn the peripheral on
      U1STAbits.UTXEN = 1;
}

只看该作者 · 2014-11-23 16:54

先关注

只看该作者 · 2014-11-23 21:16

我用pic的时候uart也经常接收错误，所以写了uart的restart函数放在程序

只看该作者 · 2014-11-26 15:37

我也有个类似的问题，接受正常，但是发送数据就是乱码

只看该作者 · 2015-1-2 01:15

我用PIC24F中断,收发都没问题.相关程序如下..

_CONFIG1( JTAGEN_OFF & GCP_OFF & GWRP_OFF & COE_OFF & FWDTEN_OFF & ICS_PGx2)
_CONFIG2( FCKSM_CSDCMD & OSCIOFNC_ON & POSCMOD_XT & FNOSC_PRIPLL & IOL1WAY_ON) //PRIPLL makes it 4X faster
_CONFIG3( WPCFG_WPCFGDIS & WPDIS_WPDIS)    //Disable erase/write protect of all memory regions.

..... .....
/****************************************************************************
void InitUART1(void)
comment: to initialize UART1 daisy chain with UART2 to communicate to ModBus VB master.
*****************************************************************************/
void InitUART1(void)
{
// configure U2MODE
U1MODEbits.UARTEN = 0;  // Bit15 TX, RX DISABLED, ENABLE at end of func
U1MODEbits.USIDL = 0; // Bit13 Continue in Idle
U1MODEbits.IREN = 0; // Bit12 No IR translation
U1MODEbits.RTSMD = 0; // Bit11 Simplex Mode
U1MODEbits.UEN = 0;    // Bits8,9 TX,RX enabled, CTS,RTS not
U1MODEbits.WAKE = 0; // Bit7 No Wake up (since we don't sleep here)
U1MODEbits.LPBACK = 0;  // Bit6 No Loop Back
U1MODEbits.ABAUD = 0; // Bit5 No Autobaud (would require sending '55')
U1MODEbits.RXINV = 0; // Bit4 IdleState = 1
U1MODEbits.PDSEL = 0; // Bits1,2 8bit, No Parity
U1MODEbits.STSEL = 0; // Bit0 One Stop Bit

U1MODEbits.BRGH = 0; // Bit3 16 clocks per bit period
U1BRG = BAUDRATEREG2; // baud rate 38400
// U1MODEbits.BRGH = 1; // Bit3 4 clocks per bit period
// U1BRG = BAUDRATEREG1; // baud rate 115200

// Load all values in for U1STA SFR
U1STAbits.UTXISEL1 = 0; //Bit15 Int when Char is transferred (1/2 config!)
U1STAbits.UTXINV = 0; //Bit14 N/A, IRDA config
U1STAbits.UTXISEL0 = 0; //Bit13 Other half of Bit15
U1STAbits.UTXBRK = 0; //Bit11 Disabled
U1STAbits.UTXEN = 0; //Bit10 TX pins controlled by periph
U1STAbits.UTXBF = 0; //Bit9 *Read Only Bit*
U1STAbits.TRMT = 0;    //Bit8 *Read Only bit*
U1STAbits.URXISEL = 0;  //Bits6,7 Int. on character recieved
U1STAbits.ADDEN = 0; //Bit5 Address Detect Disabled
U1STAbits.RIDLE = 0; //Bit4 *Read Only Bit*
U1STAbits.PERR = 0;    //Bit3 *Read Only Bit*
U1STAbits.FERR = 0;    //Bit2 *Read Only Bit*
U1STAbits.OERR = 0;    //Bit1 *Read Only Bit*
U1STAbits.URXDA = 0; //Bit0 *Read Only Bit*

IFS0bits.U1TXIF = 0; // Clear the Transmit Interrupt Flag
IEC0bits.U1TXIE = 1; // Enable Transmit Interrupts
IFS0bits.U1RXIF = 0; // Clear the Recieve Interrupt Flag
IEC0bits.U1RXIE = 1; // Enable Recieve Interrupts

IPC2bits.U1RXIP = 2; // set Interrupt priority  to 2

U1MODEbits.UARTEN = 1;  // And turn the peripheral on

U1STAbits.UTXEN = 1;
}

/************************ for uart1, daisy chain ModBus ***********************/

void __attribute__ ((interrupt, no_auto_psv)) _U1RXInterrupt(void) {
unsigned char byte1;

byte1 = U1RXREG;
U2TXREG = byte1; // start sending from TX isr
IFS0bits.U1RXIF = 0;
}
void __attribute__ ((interrupt, no_auto_psv)) _U1TXInterrupt(void) {
IFS0bits.U1TXIF = 0;
}

PIC24F串口接收的问题

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