 |
 |
| View previous topic :: View next topic |
| Author |
Message |
evaradharaj
Joined: 15 Jan 2009
Posts: 60
|
| int_rda strange problem |
 Posted: Fri Aug 12, 2011 5:53 am |
 |
|
Hi,
I am interfacing the pic16f877a with GSM sim300 module. My requirement is, when the two pins (port b0, portb 1) pins are high it should call to the specific number and should raise alarm.
If the gsm has the call from that specific number, the system should cut the call and it should not raise any alarm and call.
I have written the code and interfaced with gsm. If one ofthe inputs are high, the system is making call to the specified number without any problem(it is always working perfectly.)
But, if i want to switch off the alarm from the system, sometimes it is not working. I have tested this for more than 20 times, but 13 times it is working and 7 times is not. (Sometimes the system cuts the call from 1st ring only, sometimes with 3rd or 4th ring)..
Below i have given my code,
| Code: |
#include <16F877A.h>
#device adc=8
#FUSES NOWDT //No Watch Dog Timer
#FUSES XT //Crystal osc <= 4mhz for PCM/PCH , 3mhz to 10 mhz for PCD
#FUSES NOPUT //No Power Up Timer
#FUSES NOPROTECT //Code not protected from reading
#FUSES NODEBUG //No Debug mode for ICD
#FUSES NOBROWNOUT //No brownout reset
#FUSES NOLVP //No low voltage prgming, B3(PIC16) or B5(PIC18) used for I/O
#FUSES NOCPD //No EE protection
#FUSES NOWRT //Program memory not write protected
#use delay(clock=4000000)
#use rs232(baud=9600,parity=N,xmit=PIN_C6,rcv=PIN_C7,bits=8,ERRORS)
#include "lcd_Driver.c"
#define message_end 26
int1 flag = 0;
int i ;
char number_off[15] = {0};
int count_off = 0;
char phone_number[10] = {'9','0','4','7','8','6','3','0','0','7'}; //phonenumer
#int_RDA // receive interrupt
void RDA_isr(void)
{
number_off[count_off] = getc();
count_off ++;
}
void main()
{
int count = 0;
int i;
set_tris_b(0x8F);
output_high(pin_b7);
output_low(pin_b6);
output_low(pin_b5);
set_tris_c(0xc0);
enable_interrupts(INT_RDA);
//enable_interrupts(INT_RB);
enable_interrupts(GLOBAL);
lcd_init();
delay_ms(5000);
printf("at\n\r");
printf("at+clip=1\n\r");
printf("at+cmgf=1\n\r");
printf(lcd_putc,"WELCOME");
delay_ms(1000);
for(count = 0; count < 10; count++)
{
write_eeprom(count, phone_number[count]);
}
while(1)
{
if((input(pin_b0) || input(pin_b1))) // checking for input change
{
if(flag == 0) //checking whether the alarn disabled by user
{
output_high(pin_b6);
output_high(pin_b5);
printf("AT\n\r");
printf("ATD+"); // call to the specified number
printf("91");
for(i = 0; i < 10; i++)
{
printf("%c",read_eeprom(i));
}
printf(";\n\r");
delay_ms(15000);
printf("ATH\n\r");
delay_ms(10000);
}
}
else
{
if(number_off[count_off-1] == '+')
{
count_off = 0;
}
if(number_off[0] == '9')
{
if(count_off > 11)
{
if('1' == number_off[1] &&
read_eeprom(0) == number_off[2] &&
read_eeprom(1) == number_off[3] &&
read_eeprom(2) == number_off[4] &&
read_eeprom(3) == number_off[5] &&
read_eeprom(4) == number_off[6] &&
read_eeprom(5) == number_off[7] &&
read_eeprom(6) == number_off[8] &&
read_eeprom(7) == number_off[9] &&
read_eeprom(8) == number_off[10] &&
read_eeprom(9) == number_off[11] )
{
disable_interrupts(INT_RDA);
disable_interrupts(GLOBAL);
printf("ATH\n\r"); // to cut the call
output_low(pin_b6);
output_low(pin_b5);
for(i = 0; i < 12; i++)
{
number_off[i] = 0;
}
count_off = 0;
flag = 1;
printf("AT+CMGS="); // to send the message
putc('"');
printf("91");
for(i = 0; i < 10; i++)
{
printf("%c",read_eeprom(i));
}
putc('"');
printf("\n\r");
printf("SYSTEM IN OFF CONDITION");
printf(lcd_putc,"\nsystem off");
putc(message_end);
}
}
}
else
count_off = 0;
}
}
} |
_________________
embedding innovation in engineers |
|
 |
asmboy
Joined: 20 Nov 2007
Posts: 2128
Location: albany ny
|
|
| Posted: Mon Aug 15, 2011 4:37 pm |
|
|
First off:
Your INT_RDA handler is very unforgiving, as it makes no allowance for
for trash or unexpected characters.
If your 'key character' , 9 is not found anywhere but the first position
-
just for a START - I suggest you think about what could happen if you have TWO or more characters in the buffer when you inspect it - as in '+9' for instance.
I believe you will find it far more profitable to code a CIRCULAR receive buffer and then extract characters and examine them through another read function, so that you NEVER just blindly collapse the read buffer when the first char is not what you want.
Thus sometimes you cause the problem you have with this code.
This is NOT a CCS compiler issue - but more a problem of not understanding timing issues in async serial data reception. |
|
|
ckielstra
Joined: 18 Mar 2004
Posts: 3680
Location: The Netherlands
|
|
| Posted: Mon Aug 15, 2011 6:35 pm |
|
|
| In addition to the above info: a good example of the circular buffer implementation for serial receiving can be found in the example program ex_sisr.c |
|
|
evaradharaj
Joined: 15 Jan 2009
Posts: 60
|
|
| Posted: Wed Aug 17, 2011 5:29 am |
|
|
Thank for the replies...
I will look the code and will check in real time...
_________________
embedding innovation in engineers |
|
|
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
|
Powered by phpBB © 2001, 2005 phpBB Group
|
FAQ 
Search
Register
Profile 
Log in to check your private messages 
Log in
