Char Array, String issue for sending SMS

Projects Programming
1

Hello all,

I do want to send SMS in case some conditions are met.

I have many conditions, so there is a lot of text.

This is an working example:

void ERR000001() {
  sms.SendSMS("123456789", "sampe text sampe text sampe text sampe text sampe text");
}

However, if I do all messages like this, I run out of memory.

This is something that looked promising to me, however it does nor work.
I simply receive an integer number when I do this by SMS.

void ERR000002() {
  char m = F("sampe text sampe text sampe text sampe text sampe text");
  sms.SendSMS("123456789", m);
}

This is the libraray that I am using:

I have checked the library and found these two functions regarding SMS sending:

char SMSGSM::SendSMS(char *number_str, char *message_str)
{
     if(strlen(message_str)>159)
          Serial.println(F("Don't send message longer than 160 characters"));
     char ret_val = -1;
     byte i;
     char end[2];
     end[0]=0x1a;
     end[1]='\0';
     /*
       if (CLS_FREE != gsm.GetCommLineStatus()) return (ret_val);
       gsm.SetCommLineStatus(CLS_ATCMD);
       ret_val = 0; // still not send
     */
     // try to send SMS 3 times in case there is some problem
     for (i = 0; i < 1; i++) {
          // send  AT+CMGS="number_str"

          gsm.SimpleWrite(F("AT+CMGS=\""));
          gsm.SimpleWrite(number_str);
          gsm.SimpleWriteln("\"");

#ifdef DEBUG_ON
          Serial.println("DEBUG:SMS TEST");
#endif
          // 1000 msec. for initial comm tmout
          // 50 msec. for inter character timeout
          if (RX_FINISHED_STR_RECV == gsm.WaitResp(1000, 500, ">")) {
#ifdef DEBUG_ON
               Serial.println("DEBUG:>");
#endif
               // send SMS text
               gsm.SimpleWrite(message_str);
               gsm.SimpleWriteln(end);
               //_cell.flush(); // erase rx circular buffer
               if (RX_FINISHED_STR_RECV == gsm.WaitResp(7000, 5000, "+CMGS")) {
                    // SMS was send correctly
                    ret_val = 1;

                    break;
               } else continue;
          } else {
               // try again
               continue;

          }
     }

     gsm.SetCommLineStatus(CLS_FREE);
     return (ret_val);
}

char SMSGSM::SendSMS(byte sim_phonebook_position, char *message_str)
{
     char ret_val = -1;
     char sim_phone_number[20];

     ret_val = 0; // SMS is not send yet
     if (sim_phonebook_position == 0) return (-3);
     if (1 == gsm.GetPhoneNumber(sim_phonebook_position, sim_phone_number)) {
          // there is a valid number at the spec. SIM position
          // => send SMS
          // -------------------------------------------------
          ret_val = SendSMS(sim_phone_number, message_str);
     }
     return (ret_val);

}

Any ideas how I could store the long strings in Flash memory by using F and keep this thing working?

Kr,

Andreas

2

Not the F macro but using PROGMEM.

3

Thanks, so I guess you are referencing for the section: Putting the strings themselves into PROGMEM

However I would like to understand why F() isnt working in this case.

4

Andreas1984:
Thanks, so I guess you are referencing for the section: Putting the strings themselves into PROGMEM

However I would like to understand why F() isnt working in this case.

what is a char?

after you consider that question, consider this:

char m = F("sampe text sampe text sampe text sampe text sampe text");
5

This thread may explain why you can't use the F macro in an assignment. If I understand correctly, the F macro creates a pointer to the constant string, thus the integer that was returned.