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How to process the data from UART?

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)
{
memcpy(sHeadFlag,&r_buf[(r_out+1)&0x7ff],5);
if (memcmp(sHeadFlag,sGpgs[0],5)==0)
{
GpgsvSol(&r_buf[r_out&0x7ff]);
}
if (memcmp(sHeadFlag,sGpgs[1],5)==0)
{
GpgsaSol(&r_buf[r_out&0x7ff]);
atelliteLocked=Gpgsa.cSatInSolTol;
}
}
r_out++;
}
}
} ) { memcpy(sHeadFlag,&r_buf[(r_out+1)&0x7ff],5); if (memcmp(sHeadFlag,sGpgs[0],5)==0) { GpgsvSol(&r_buf[r_out&0x7ff]); } if (memcmp(sHeadFlag,sGpgs[1],5)==0) { GpgsaSol(&r_buf[r_out&0x7ff]); atelliteLocked=Gpgsa.cSatInSolTol; } } r_out++; } } }
How can i correct it well?
Thanks.
DetailsMessage
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Author
Nantian Gumo
Posted
20-Mar-2005 15:14 GMT
Toolset
C51
New! How to process the data from UART?
Hi all .
In one way ,all the messages is following a standard format ,like:"SOH,MSG ID, CMPL ID,MSG DATA LENGTH, MSG DATA ,CHECKSUM",so this format can be embed in UART_ISR to receive the message wanted.But,if have some different kinds of message which following different formats ,or baudrate is too high to process in the UART_ISR,how can the firmware process these message?Where have any referenced source code ?
Thanks for help.
Read-Only
Author
Hans-Bernhard Broeker
Posted
21-Mar-2005 13:21 GMT
Toolset
C51
New! RE: How to process the data from UART?
It's quite certainly not a good idea to do any processing like the one you're talking about inside the ISR. Let the main code deal with it. All the ISR can usefully do is receive the data, a byte at a time, and push it into a circular buffer of adequate size. The main code will pull it out of that, and do whatever needs being done.
Read-Only
Author
A.W. Neil
Posted
21-Mar-2005 13:31 GMT
Toolset
C51
New! RE: How to process the data from UART?
"All the ISR can usefully do is receive the data, a byte at a time, and push it into a circular buffer of adequate size. The main code will pull it out of that, and do whatever needs being done."

Absolutely.
Look at the interrupt-driven serial IO sample code on this very site.

I've used it almost straight from the can to do exactly the kind of thing you're talking about.
Read-Only
Author
Nantian Gumo
Posted
24-Mar-2005 14:43 GMT
Toolset
C51
New! RE: How to process the data from UART?
I have tried my best ,but couldn't find the code example what you said.Can you tell me which site they are?
Thanks a lot!
Read-Only
Author
A.W. Neil
Posted
24-Mar-2005 15:02 GMT
Toolset
C51
New! RE: How to process the data from UART?
Click 'Support' in the blue bar across the top of this screen

Click 'Download Files'

Click 'C51 Downloas Files'

Look for "Interrupt-Driven Serial I/O"
(Hint: use your browser's 'Search' facility)
Read-Only
Author
Nantian Gumo
Posted
26-Mar-2005 07:28 GMT
Toolset
C51
New! RE: How to process the data from UART?
Hi all,
when the main_loop's code shown as following is running ,lots of messages in buffer couldn't be detected and lost.can you tell me how to correct it?

Serial ISR:
void serial0(void) interrupt 4
{
ES0 = 0;
if (TI0) TI0 =0;
if (RI0)
{
r_buf[r_in&0x7ff]=SBUF0;
RI0 = 0;
r_in=r_in+1;
}
ES0 = 1;
}
Main_Loop:
void main()
{
...
while(1)
{
if ((r_in-r_out)>128)
{
serial0Flag = 1;
}
if(serial0Flag==1)
{
if (r_buf[r_out&0x7ff] =='
Read-Only
Author
A.W. Neil
Posted
26-Mar-2005 07:55 GMT
Toolset
C51
New! RE: How to process the data from UART?
Your code is illegible because it's lost all its latout/formatting.
This is because you didn't follow the instruction about posting code.

Please follow the instructions on how to post code - it's right there immediately above the box where you type your message!
http://www.keil.com/forum/tips.asp
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Author
Dan Henry
Posted
26-Mar-2005 19:46 GMT
Toolset
C51
New! RE: How to process the data from UART?
Once serial0Flag has been set to 1, your main loop will scan r_buf[] continuously without any synchronization to the incoming data and without checking whether it's looking at old data after wrapping.
Read-Only
Author
Nantian Gumo
Posted
27-Mar-2005 06:49 GMT
Toolset
C51
New! RE: How to process the data from UART?
I rewrite the source code as following:
//Serial ISR:
void serial0(void) interrupt 4
{
    ES0 = 0;
    if (TI0) TI0 =0;
    if (RI0)
    {
        r_buf[r_in&0x7ff]=SBUF0;
        RI0 = 0;
        r_in=r_in+1;
    }
    ES0 = 1;
}
//Main_Loop:
void main()
{
...
while(1)
{
    if ((r_in-r_out)>128)
    {
        serial0Flag = 1;
    }
    if(serial0Flag==1)
    {
        if (r_buf[r_out&0x7ff] =='

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