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Hi all,
I'm using 89C52 controller in my application. I'm using a 90 byte buffer to store received message from UART. Based on this received message I'm controlling I/O ports. The same buffer I'm using for transmitting the application dependent internal status message.
To identify the message I'm using absolute address position for example, if(arr[59] == '*'){do something;}
every first message after reset this is working fine. After that the control hangs somewhere thus its giving undetermined behavior.
I set the memory model as Large: all variables in XDATA.
I hope some address overflow is happening here.
Can anyone help me to resolve this issue.
Thanks in Advance.
Regards, Ramesh
Thank you very much for your message.
Actually I'm using polling method of message reception not Interrupt method.
I have used two buffers of size arr[35] arr1[35] one for Txd and other for Rxd. There also same behavior.
In this method it was working when im keep on reciving the message that means i'm using only arr[35] buffer.
At the moment i started using the second buffer arr1[35] for transmitting. Its transmitting the message correctly and cpu hangs. only way i have to reset the controller.
I think there is some severe memory overflow/system stack overflow happens when we are using array of characters.
Expecting some suggestions. Thanks.
but how can you see so sure about this? many other issues can be the cause. did you try to strip your program of everything which is not absolutely necessary (as your problem can be triggered by an interaction of some kind)? does you controller finish handling a message in one polling cycle (if not, maybe you overwrite not-yet-processed data)? can you post clear and outlines code related to the problem?
HAVE YOU SEEN THE KNOWLEDGE BASE FOR COMPILAR BUGS>?
DO YOU IDE USE THE OLD VERSION?
ANY ERRORS!
Exactly why would screaming help?
Anyway - do not use variable names arr and arr1. They are meaningless. What are the buffers? rx_buf[] and tx_buf[] or do you have two two receive buffers?
Here is my code fragment:
#include<serial.h> #include <AT89X52.H> unsigned char message[35]; unsigned char Request[35]; main() { unsigned char i,j,;
Init_Uart(); // UART functionlity working fine with 9600 baud while(1) { for(i=0;i<=35;i++) { message[i]=RX_CHAR(); //Rx buffer for first 35 char's controll waits here for incoming char process=1; }
if(process==1) {
if(message[25]=='*') // I'm sure that this characters are 26th character always from transmitter {pass =1; TestLED=ON;} else if(message[25]=='#') {pass =0;TestLED=OFF;} process =0; }
if(pass==1) { for(j=0;j<=35;j++) { Request[j]= 'A';
} Send_Str(Request); // Request array is transmitted Note this subroutine is tested working correctly
} else if( pass==0) { for(j=0;j<=35;j++) { Request[j]= 'B';
} Send_Str(Request); // Request array is transmitted }
} }
Please suggest.
re-post using the proper tags please!
Please see my code in the previous thread.
Thanks
SEE
(i=0;i<=35;i++)
BUFFER IS
xxx[35]
YOU ARE GOUNNG TOOO FAR!
Anyway - do not use variable names arr and arr1. They are meaningless.
... unless you're a pirate.
Here is the code again..
#include<serial.h> #include <AT89X52.H>
unsigned char message[35]; unsigned char Request[35];
main() { unsigned char i,j;
// UART functionlity working fine with 9600 baud
Init_Uart(); while(1) { for(i=0;i<=35;i++)
{
//Rx buffer for first 35 char's // controll waits here for incoming char
message[i]=RX_CHAR(); process=1;
}
if(process==1)
// I'm sure that this characters are 26th // character always from transmitter
if(message[25]=='*')
pass =1; TestLED=ON;
else if(message[25]=='#')
pass =0; TestLED=OFF;
process =0;
if(pass==1)
for(j=0;j<=35;j++)
Request[j]= 'A';
// Request array is transmitted Note this // subroutine is tested working correctly.
Send_Str(Request); }
else if( pass==0)
Request[j]= 'B';
Send_Str(Request);
} } }
YOURE POSTED CODE IS STILL WRON GSEE MY LAST ANSWRE!
Please post a link to your previous thread then. There is no button to move to the next/previous thread written by you.
unsigned char message[35]; unsigned char Request[35]; for(i=0;i<=35;i++) { //Rx buffer for first 35 char's // controll waits here for incoming char message[i]=RX_CHAR(); process=1; } for(j=0;j<=35;j++) { Request[j]= 'A'; }
YOU ARE FILLIN G A 35 CHARACTER ARRAY WIT H36 CHARACTERS!
THAT IS OVERFLOW!
narak, don't you think it is only appropriate to also SCREAM in the code that you post?!
<QUOTE>don't you think it is only appropriate to also SCREAM in the code that you post?!</QUOTE>
HE DOES NOT WANT TO LISTEN TO MY ANSWER WHO I THINK IS CORRE CT!
IS HE DEF?
the OP probably already implemented your careful advise. there is no need to use UPPERCASE. that won't make his listen - just annoy everyone else.