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Message |
hoangkhuong
Joined: 16 Mar 2012
Posts: 31
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| Problem in sending sms with sim300 |
 Posted: Mon May 21, 2012 10:06 am |
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Hello everyone, I am trying to send sms using SIM300. Here is my code:
| Code: | #include <30F4011.h>
#DEVICE ADC=10
#FUSES NOWDT, NOPUT, NOPROTECT, NODEBUG, BROWNOUT, NOWRT
#FUSES XT_PLL4
#use delay(clock=4000000)
#include "LCD.h"
#use rs232(baud=2400,parity=N,xmit=pin_f5,rcv=pin_f4,bits=8,errors)
void main()
{
char c;
char s = 0x1A;
set_tris_b(0x00);
lcd_init();
delay_ms(20);
printf("AT\r");
delay_ms(100);
printf("ATE0\r");
delay_ms(100);
printf("AT+CMGF=1\r");
delay_ms(100);
printf("AT+CMGS=+80934525189\r");
delay_ms(100);
printf("hello\r");
putc(s);
lcd_gotoxy(1,2);
while (true)
{
c = getc();
printf(lcd_putc,"%c",c);
}
} |
My problem is: sometimes I receive the right message "hello" but sometimes I receive a message like this:
| Code: | AT
ATE0
AT+CMGF=1
AT+CMGS=+80934525189
hello |
Can somebody please help me figure out what is wrong in my code?.
Thank you very much. |
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ezflyr
Joined: 25 Oct 2010
Posts: 1019
Location: Tewksbury, MA
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| Posted: Mon May 21, 2012 10:58 am |
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Hi,
A couple of things. You really should be making some attempt to read the responses from the SIM300 to see what is going on during the SMS sending process. That might help you to determine why your code is behaving the way it is?
Also, an SMS message is sent by sending a Cntl-Z to the modem. I don't know what you are sending, but it doesn't look right. Do it like this:
| Code: |
putc(26); //send the msg with a CNTL-Z
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John |
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hoangkhuong
Joined: 16 Mar 2012
Posts: 31
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| Posted: Mon May 21, 2012 11:02 am |
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| Thanks for your response. First of all, I did sent a CTRL+Z character at the end of the sending message command, it is 0x1A which is in decimal is 26 as you suggest. Secondly, I did used PC to check the response from SIM300 and things work fine. Problem arises when I try to communicate between mcu and sim300 :( |
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ezflyr
Joined: 25 Oct 2010
Posts: 1019
Location: Tewksbury, MA
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| Posted: Mon May 21, 2012 12:29 pm |
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Hi,
Sorry, I didn't read your code closely enough to see that you are in fact sending the Cntl-Z.
I realize that problems arise when you communicate between the PIC and the SIM300, and that is why I recommended that you actually read the modem response with the PIC. At the very least, connect the Tx line from the modem to your PC (via a MAX232) to aid in your diagnosis.
I'd also recommend that you try some longer delays after setting the phone number, and setting the message text. I would try something like 2 seconds as a start. If that helps, you can reduce the delays until it fails.
John |
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hoangkhuong
Joined: 16 Mar 2012
Posts: 31
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| Posted: Tue May 22, 2012 10:41 am |
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Yes, I've solved my problem by increasing the delay time after AT+CMGS command to 3 seconds.
Thanks very much. |
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ezflyr
Joined: 25 Oct 2010
Posts: 1019
Location: Tewksbury, MA
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| Posted: Tue May 22, 2012 1:15 pm |
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Hi,
Great! I'm using 2 seconds with a different GSM module (ADH8066), and it's always worked great!
Glad I could help!
John |
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savotech
Joined: 13 Dec 2012
Posts: 12
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| Posted: Fri Apr 25, 2014 3:25 pm |
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Hi, please help me out.
I am using SIM908 modem, i tried the code hungkuoung used buy couldnt get any sms on the phone.
Do i need to set sms centre number?
Do i need to add country phone code
And the baud that i used is 9600 since i read that the module is autobaud by default.
I didnt use pc to monitor reply cos my laptop didnt have serial port.
So please anybody with useful info |
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ezflyr
Joined: 25 Oct 2010
Posts: 1019
Location: Tewksbury, MA
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| Posted: Fri Apr 25, 2014 6:10 pm |
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Hi,
Post a link to the SIM908 module you are using so that we can start by evaluating your hardware interface. I'm using a bare SIM900 module, so I should be able to help!
John |
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