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carlosma
Joined: 24 Mar 2004
Posts: 53
Location: Portugal
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| times between commands |
 Posted: Tue Jul 13, 2004 6:18 am |
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Hello
My program stop when I read a incoming message from a GSM Modem and I thing the problem is the times between commands.
Somebody can help me? Therefore already I tried all posts related with SMS reading.
some code:
| Code: |
//...
OFF_int(); //desable INT_ext and INT_rda
delay_ms(100);
fprintf(COM_B, "AT+CMGR=1\n"); //command to read message
delay_us( 1000 );
do { //wait for CR
c=fgetc(COM_B);
} while (c!=13);
letra =0;
do { //save text message
buffer1[letra]=fgetc(COM_B);
letra++;
} while (letra == 16);
read_int_eeprom_string(s, ROM_mensagem, ROM_mensagem_SIZE); // read from eeprom text to compare
if (strncmp (buffer1, s, 8)==0) //compare both message
{
fprintf(COM_A,"Turn ON\r\n");
output_high (pin_b5);
}
//... continue
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Thank you
Carlos |
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SherpaDoug
Joined: 07 Sep 2003
Posts: 1640
Location: Cape Cod Mass USA
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| Posted: Tue Jul 13, 2004 7:37 am |
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Are you using a software UART? If so the CPU is entirely occupied while reading serial data.
Rather than reading in a whole buffer full of data and then comparing, I would compare each character as it comes in. That way you don't use two buffers of RAM space. Even with characters coming in with no inter character space you usually have at least half the stop bit time to process the old character before you need to start reading the new character.
Also this line looks wrong
} while (letra == 16);
should it be <= instead of == ?
_________________
The search for better is endless. Instead simply find very good and get the job done. |
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carlosma
Joined: 24 Mar 2004
Posts: 53
Location: Portugal
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| Posted: Tue Jul 13, 2004 7:59 am |
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No
I use hardware port like
| Code: |
#use rs232(baud=1200, xmit=PIN_C6, rcv=PIN_C7, PARITY=n, bITS=8, STREAM=COM_B, ERRORS) //hardware
#USE RS232(BAUD=9600, XMIT=PIN_B1, RCV=PIN_B0, STREAM=COM_A, ERRORS)
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Already I tried to compare while it read, but had problems with CR and LF.
Thank you
Carlos |
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Guest
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| Posted: Tue Jul 13, 2004 8:53 am |
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Your uart is overflowed.
First of all, you have to init your GSM adapter by a
ATE0+CMGF=1
command to disable local echo and to set text mode. Without local echo disabled, your commands is echoed to the PIC. Your INT_RDA is disabled, so the receiver circuit is fullfilled after the 'T' char of your AT+CMGR command. Once the receiver is overflowed, it stops the work. The ERRORS will clear this state _after_ the first incoming char what is the 0x0D. So you will never get the first 0x0D (a typical answer from the adapter looks like this:
0x0D 0x0A +CMGR: 1 0x0D 0x0A YourText............... 0x0D 0x0A
So use either IT-driven receive or wait for 10 dec. (0x0A) in your loop (that is the 2nd char at the beginning). |
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