PIC24菜鸟毕业留念---GPS串口2接收中断服务程序

2万 · 2007-12-20 02:49

/*------------------------------------------------------------------------
                   GPS串口2接收中断服务程序(接收GPS数据)
菜农HotPower之PIC24菜鸟毕业留念    2007.12.20   2:40 于菜地留念
-------------------------------------------------------------------------*/
void __attribute__((interrupt, no_auto_psv)) _U2RXInterrupt( void )
{
static unsigned char cData = 0, cPosition;
unsigned char ch;
    if (IFS1bits.U2RXIF)//确实是GPS串口2接收中断
    {
        if (IEC1bits.U2RXIE)//GPS串口2接收中断已被允许
        {
            ch = U2RXREG;//读取串口GPS数据
            if (ch == '$')//是GPS引导字符
            {
                cData = ch;//记录引导字符
                cPosition = GPSRxWriteCount;//引导字符位置记录
                GPSRxBuffers[GPSRxWriteCount ++] = ch;//存入数据
            }
            else if (cData == '$')//收到引导字符
            {
                if (ch >= ' ')//可能是有效数据
                {
                    GPSRxBuffers[GPSRxWriteCount ++] = ch;//存入数据
                }
                else if (ch == '*')//GPS校验引导字符
                {
                    GPSRxBuffers[GPSRxWriteCount ++] = ch;//存入数据
                }
                else if ((ch == '\r') && (GPSRxBuffers[GPSRxWriteCount - 3] == '*'))//回车字符校验
                {
                    GPSRxBuffers[GPSRxWriteCount ++] = ch;//存入数据
                }
                else
                {
                    if ((ch == '\n') && (GPSRxBuffers[GPSRxWriteCount - 1] == '\r'))//换行字符校验
                    {//只取GPRMC语句
                        if (GPSGPRMCTest((char *)&GPSRxBuffers[cPosition + 1]))
                        {
                            GPSRxBuffers[GPSRxWriteCount ++] = ch;//存入数据
                            GPSbits.RXFlag = 1;//激活GPS接收成功解码程序(在“零耗时键盘OS”的空闲任务内细加工处理)
                        }
                    }
                    cData = 0;//结束或出错
                }
            }
            else
            {
                cData = 0;//出错
            }
        }
    }
     IFS1bits.U2RXIF = 0;//清除RX2中断标志
}

/*------------------------------------------------------------------------
    GPS串口2初始化程序
-------------------------------------------------------------------------*/
void Uart2Init(void)
{
    TRIS_TX2 = PORTOUTMODE;//设置TX2为输出IO
    TRIS_RX2 = PORTINPUTMODE;//设置RX2为输入IO
    U2MODE = 0;
//    U2MODEbits.STSEL = 0;// 1-stop bit
//    U2MODEbits.PDSEL = 0;// No Parity, 8-data bits
//    U2MODEbits.ABAUD = 0;// Autobaud Disabled
    U2STA = 0;
//    U2STAbits.UTXISEL0 = 0;            // Interrupt after one Tx character is transmitted
//    U2STAbits.UTXISEL1 = 0;
//    U2STAbits.URXISEL  = 3;            // Interrupt after one RX character is received
    U2BRG = BRGVAL2;//BAUD Rate Setting for 19200
    U2MODEbits.WAKE    = 1;//启动位时唤醒使能位
    U2MODEbits.UARTEN   = 1;        // Enable UART
    U2STAbits.UTXEN     = 1;        // Enable UART Tx
/*------------------------------------------------------------------------
    定义GPS串口2中断优先级位1111)
-------------------------------------------------------------------------*/
    IPC7bits.U2RXIP0 = 1;
    IPC7bits.U2RXIP1 = 1;
    IPC7bits.U2RXIP2 = 1;
    IEC1bits.U2RXIE = 1;
    IFS1bits.U2RXIF = 0;//清除RX1中断标志
    IEC1bits.U2TXIE = 1;
    IFS1bits.U2TXIF = 0;//清除TX1中断标志
}