Send SMS from PIC to GSM Modem

[peter2020]

Currently I'm doing on a project interfacing PIC16F877 with GSM Modem (MOD9001).
However, I failed to send sms from the PIC through the GSM Modem.
Is there anyone can help me to check on my coding? Am I doing the wrong coding?
The following is my coding:

#include <16f877a.h>
#include <stdio.h>
#use delay (clock = 20000000)
#fuses hs, noprotect, nowdt, nolvp
#define use_portb_lcd true
#use rs232(baud=9600, bits=8, xmit=pin_c6,rcv=pin_c7, parity=n, stream=GSM)

#byte portb=6
#byte portc=7
#byte portd=8

void main ()
{
set_tris_b(0);

fprintf(GSM,"at\r\n");
delay_ms(1000);

fprintf(GSM, "at+cmgf=1\r\n");
delay_ms(2000);

fprintf(GSM,"at+csmp=17,168,0,0\r\n");
delay_ms(2000);

fprintf(GSM, "at+cmgs=\"+601xxxxxx\"\r\n"); //xxxxxx is my phone #
delay_ms(2000);

fprintf(GSM, "TEST1..");
delay_ms(5000);

putc(0x1A);
delay_ms(5000);

}

 

[GSM Man]

You should not be depending on fixed delays between commands, rather you should receive the response from the module and process it. If you look at the responses from the module it may provide an answer to you problem

How do you know if you're even communicatiing with the module? How do you know that you are not receiving an error from the module for one of your commands? Is the SMS Message Center Number set - "AT+CSCA" command? Has the module registered with the network?