A little side project I'm playing with!
I have a number of GSM based "free call remote controls" I use for various tasks.
They work by matching the caller ID of an incoming call to an "authorised" list and activating a relay.
The incoming call is never answered and hence no call cost apart from $3 /month SIM for the device
My issue is that Telstra is killing off the GSM network here in Australia in the next two years and these devices will need replacing - and currently there is no replacement I can find.
So while I am playing with all things 3G at the moment I thought I'd have a go at replicating this device but on a 3G module.
Digging around I found some code for "BeeGSM" and I have modified it and its libraries to work with my SIM5216a modules and have this very basic code working. I have manually added a couple of numbers to the SIM via AT commands direct to the 3G module and the code works
(I have yet to rename the libraries - it was originally based on a Teltonika module)
#include <TeltonikaTM1Q.h>
#include <SoftwareSerial.h>
#define RELAYPIN 5
#define SYS_PIN ("1234")
char number[20];
char name[20];
char smsbuffer[160];
int index;
boolean auth;
void setup()
{
//Serial connection.
Serial.begin(9600);
Serial.println("Free Call Remote Control");
//Start configuration.
gsm.debug(false);
if (gsm.begin())
Serial.println("\nstatus=READY");
else Serial.println("\nstatus=IDLE");
pinMode(RELAYPIN, OUTPUT);
digitalWrite(RELAYPIN,HIGH);
};
void loop(){
if(gsm.readSMS(smsbuffer, 160, number, 20)){
Serial.print("Number: ");
Serial.println(number);
Serial.print("Message: ");
Serial.println(smsbuffer);
String SMS_COMMAND = smsbuffer;
if (SMS_COMMAND.startsWith(SYS_PIN)){
Serial.println("PIN MATCH!");
if (SMS_COMMAND.startsWith("#TEL",4)){
Serial.println("TEL COMMAND");
if (SMS_COMMAND.startsWith("#",8)){
Serial.println("Remove number command");
//remove number from phonebook routine here
}
else{
Serial.println("Add number command");
//add number to phonebook routine here
}
}
}
}
if(gsm.readCallAuthPhoneBook(number,20,auth)) {
if(auth) {
Serial.print("Number ");
Serial.print(number);
Serial.println(" authorized !");
Serial.println("Relay ON");
digitalWrite(RELAYPIN, LOW);
delay(1000);
digitalWrite(RELAYPIN, HIGH);
delay(1000);
Serial.println("Relay OFF");
}
else {
Serial.print("Number ");
Serial.print(number);
Serial.println(" is not authorized!");
}
}
}
You can see I've just started playing with the receiving SMS portion that allows you to program authorised numbers on the SIM. Recognizing a command prefixed with the command password (SYS_PIN), the #TEL command to add a new number or the #TEL# command to remove one.
My next issue is how to parse out the phone number & index location that will follow on from the #TEL command from either "smsbuffer" or "SMS_COMMAND"
ie the full command may look like this:
1234#TEL0123456789#01
where:
SYS_PIN = 1234
Mobile number to add = 0123456789
#01 at the end = phonebook index location
How do I grab the full phone number including and LEADING zeros and also the index location?
I have this routine to write to the SIM phonebook:
void WRITE_SIM_PHONEBOOK(){
if (gsm.writePhoneBook(number," "));
}
Currently this will just dump the new number into the first available free index location, but I hope to be able to push the number to specific locations.
