做过COM口编程的大哥们帮帮忙啊
1、每字节数据由10位组成，一个起始位，一个停止位， 8个数据位。
2、数据采用ASCII码格式。
3、数据传输速率可调（1200－115200）。
4、数据格式：0x02 ST ID WT 0x0d XOR，共计18字节，除起始、结束和校验字节外均为ASCII码
0x02：起始字节
ST： 1位状态，0x31
ID： 7位编号
WT： 6位重量
DN： 1位小数点位置
0x0d：结束字节
XOR： 前17字节的异或值
如：02 31 33 34 35 36 37 38 39 30 30 30 35 38 32 31 0d 32，代表ID号为3456789，重量为58.2kg
这是一个电子称的协议，我该怎么写啊？
[解决办法]
/*------------------------------*
GSERIAL.CPP
For asynchronous serial port communications
适用于DOS环境下异步串口通信编程
ATTENTION: Compile this program with Test Stack Overflow OFF.
在Turbo C++3.0中选项设置 Options/Compiler/Entry中关闭Test Stack Overflow
*------------------------------*/
#include "GSerial.h "
char inbuf[IBUF_LEN];// in buffer
char outbuf[OBUF_LEN];// out buffer
unsigned int startbuf = 0;
unsigned int endbuf = 0;
unsigned int inhead = 0;
unsigned int intail = 0;
unsigned int outhead = 0;
unsigned int outtail = 0;
unsigned int PortBase = 0;
GSerial::GSerial()
{
}
GSerial::~GSerial()
{
}
//* get status of the port */
int GSerial::ReadStatus(void)
{
return(inp(m_unPortBase+5));
}
/* send one valid char from the port */
void GSerial::SendChar(unsigned char unCh)
{
while ((ReadStatus() & 0x40) == 0);
outportb(m_unPortBase,unCh);
}
/* send one string from the port */
void GSerial::SendString(int nStrlen, unsigned char *unChBuf)
{
int k=0;
do {
SendChar(*(unChBuf + k));
k++;
} while ((k < nStrlen));
}
/* Install our functions to handle communications */
void GSerial::SetVects(void interrupt(*New_Int)(...))
{
disable();
OldVects = getvect(InterruptNo[m_unPortNo-1]);
setvect(InterruptNo[m_unPortNo-1], New_Int);
enable();
}
/* Uninstall our vectors before exiting the program */
void GSerial::ResetVects(void)
{
setvect(InterruptNo[m_unPortNo-1], OldVects);
}
/* Tell modem that we 're ready to go */
void GSerial::CommOn(void)
{
int temp;
disable();
//temp = inportb(m_unPortBase + MCR) | MCR_INT;
//outportb(m_unPortBase + MCR, temp);
outportb(m_unPortBase + MCR, MCR_INT);
//temp = inportb(m_unPortBase + MCR) | MCR_DTR | MCR_RTS;
//outportb(m_unPortBase + MCR, temp);
temp = (inportb(m_unPortBase + IER)) | IER_RX_INT;//|IER_TX_INT;
outportb(m_unPortBase + IER, temp);
temp = inportb(PIC8259_IMR) & ComIRQ[m_unPortNo-1];
outportb(PIC8259_IMR, temp);
enable();
}
/* Go off-line */
void GSerial::CommOff(void)
{
int temp;
disable();
temp = inportb(PIC8259_IMR) | ~ComIRQ[m_unPortNo-1];
outportb(PIC8259_IMR, temp);
outportb(m_unPortBase + IER, 0);
outportb(m_unPortBase + MCR, 0);
enable();
}
/* Set the port number to use */
int GSerial::SetPortBaseAddr(int Port)
{
if((Port <1)||(Port> 6))
return(-1);
m_unPortNo = Port;
m_unPortBase = PortBaseAddr[m_unPortNo-1];
return (0);
}
/* This routine sets the speed; will accept funny baud rates. */
/* Setting the speed requires that the DLAB be set on. */
int GSerial::SetSpeed(int Speed)
{
charc;
intdivisor;
if (Speed == 0) /* Avoid divide by zero */
return (-1);
else
divisor = (int) (115200L/Speed);
if (m_unPortBase == 0)
return (-1);
disable();
c = inportb(m_unPortBase + LCR);
outportb(m_unPortBase + LCR, (c | 0x80)); /* Set DLAB */
outportb(m_unPortBase + DLL, (divisor & 0x00FF));
outportb(m_unPortBase + DLH, ((divisor > > 8) & 0x00FF));
outportb(m_unPortBase + LCR, c); /* Reset DLAB */
enable();
return (0);
}
/* Set other DATA Format communications parameters */
int GSerial::SetDataFormat(int Parity, int Bits, int StopBit)
{
int setting;
if (m_unPortBase == 0)
return (-1);
if (Bits < 5 || Bits > 8)
return (-1);
if (StopBit != 1 && StopBit != 2)
return (-1);
if (Parity != LCR_NO_PARITY && Parity != LCR_ODD_PARITY && Parity != LCR_EVEN_PARITY)
return (-1);
setting = Bits-5;
setting |= ((StopBit == 1) ? 0x00 : 0x04);
setting |= Parity;
disable();
outportb(m_unPortBase + LCR, setting);
enable();
return (0);
}
void GSerial::CloseSerialPort(void)
{
CommOff();
ResetVects();
}
/* Set up the port */
int GSerial::InitSerialPort(int Port, int Speed, int Parity, int Bits, int StopBit)
{
int flag = 0;
if (SetPortBaseAddr(Port))
flag = -1;
if (SetSpeed(Speed))
flag = -1;
if (SetDataFormat(Parity, Bits, StopBit))
flag = -1;
return(flag);
}
void interrupt ComIntServ(...)
{
int temp;
disable();
temp = (inportb(PortBase+IIR)) & IIR_MASK;// why interrupt was called
switch(temp)
{
case 0x00: // modem status changed
inportb(PortBase+MSR); // read in useless char
break;
case 0x02: // Request To Send char
if (outhead != outtail)// there 's a char to send
{
outportb(PortBase+TXR,outbuf[outhead++]);// send the character
if (outhead == OBUF_LEN)
outhead=0;// if at end of buffer, reset pointer
}
break;
case 0x04: // character ready to be read in
//inbuf[inhead++] = inportb(m_unPortBase+RXR);// read character into inbuffer
inbuf[inhead] = inportb(PortBase+RXR);// read character into inbuffer
inhead++;
if (inhead == IBUF_LEN) // if at end of buffer
inhead=0; // reset pointer
break;
case 0x06: // line status has changed
inportb(PortBase+LSR); // read in useless char
break;
default:
break;
}
outportb(PIC8259_ICR, PIC8259_EOI);// Signal end of hardware interrupt
enable();// reenable interrupts at the end of the handler
}
// Returns either the character to be received from modem if there is one
// waiting in the buffer, or returns a 0 if there is no character waiting.
char ReadChar(void)
{
char ch;
if (inhead != intail) // there is a character
{
disable(); // disable irqs while getting char
ch = inbuf[intail++]; // get character from buffer
if (intail == IBUF_LEN)// if at end of in buffer
intail=0;// reset pointer
enable(); // re-enable interrupt
return(ch); // return the char
}
ch = -1;
return(ch); // return nothing
}
///////
main()
{
/* Communications parameters */
int port = COM1;
int speed = 9600;
int parity = LCR_NO_PARITY;
int bits = 8;
int stopbits = 1;
int done = FALSE;
char c;
int temp;
int SError=0;
GSerial gs;
if (!gs.InitSerialPort(port, speed, parity, bits, stopbits))
{
PortBase = PortBaseAddr[port-1];
gs.SetVects(ComIntServ);
gs.CommOn();
}
else
SError=2;
fprintf(stdout, "\nCOM%d, PortBase=0X%x, IntVect=0X%x\n\n ",gs.m_unPortNo,gs.m_unPortBase,ComIRQ[gs.m_unPortNo-1]);
fprintf(stdout, "TURBO C TERMINAL\n "
"...You 're now in terminal mode, "
"press [ESC] to quit...\n\n ");
/*
The main loop a MSR_CTS as a dumb terminal. We repeatedly
check the keyboard buffer, and communications buffer.
*/
do {
if (kbhit())
{
c = getch();
/* Look for an Escape key */
switch (c)
{
case ESC:
done = TRUE; /* Exit program */
break;
}
if (!done)
{
gs.SendChar( c );
fprintf(stdout, "%c ",c);
}
}
c = ReadChar();
if (c != -1) // '-1 ' is the END signal of a string
{
fprintf(stdout, "%c ",c);
}
//fprintf(stdout, "%d ",testtemp);
} while ((!done) && (!SError));
gs.CloseSerialPort();
/* Check for errors */
switch (SError)
{
case NO_ERROR: fprintf(stderr, "\nbye.\n ");
return (0);
case BUF_OVFL: fprintf(stderr, "\nBuffer Overflow.\n ");
return (99);
case 2: fprintf(stderr, "\n Cannot init serial port ");
return(2);
default: fprintf(stderr, "\nUnknown Error, SError = %d\n ",
SError);
return (99);
}
}
[解决办法]
只是一个协议而已，具体实现的代码我以前发过这样的帖子，你可以找一下。我用的是RTU模式
[解决办法]
协议可以自己定义的，连接com的两端都一样就可以了。怎么组帧发送，就同样的规则解析。
一楼不是c#程序，是c++代码。
c#2005写串口很简单。有个serialPort类。
[解决办法]
同意 whChina(江城老温)，楼主安装VS.net 2005吧，用SerialPort控件真的很方便
[解决办法]
部分代码：
SerialPort sp = new SerialPort();
if (!sp.IsOpen)
{
sp.Open();
}
Thread.Sleep(200);
sp.Read(by, 0, by.Length);
string instring = Encoding.ASCII.GetString(by);
[解决办法]
用VB msComm比较好。
