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Interfacing the PIC18F452 with the GM862 module is relatively simple. What will be left is only the code that needs to be burned on the PIC. By the way,no full codes will be posted here. I will only post the codes that will give you a good kick start because I think it is better to understand than to copy and paste. And there is a Chinese saying:

Give a man a fish, you feed him for a day.
Teach him to fish, and you feed him for lifetime.

This is a sample project that I made and it only deals with making phone calls and I will upload other videos for SMS, GPRS and Data Call:

Now looking at the schematics you will find all the details on how to connect both the module and the PIC.

After doing the above connections, you need to start the module first and then initiate the baudrate that both of them will work on. The Telit module works on different values of baudrates (300, 1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200). For me I shall work with baudrate 19200, but you can choose whatever baudrate that you want.

To start the module, you simply connect the ON_OFF pin to the ground for at least 1 sec (note: this pin is normally high). So you can do this by two ways. First way is to connect a switch and give the ON signal by hand, which is not a good idea. The second way which all of you will do, is to let the PIC18F452 do the job of turning the module ON. We will connect a transistor as shown in the schematic (PN2222A) such that when the base voltage is high, it allows the current to pass to the ground. So, you will need to make PORTC.PIN5 to be HIGH for 1 sec and then toggle it back to LOW (safety factor make it 1.1 sec).

So, after initializing the baudrate on the PIC you need to do the following at the start of your program:

while(recieved_serial!='AT;\nOK\r\n'){
send_serial('AT\r');
delay_ms(300);   //Delay 300 mSec
}

(continue reading…)

This is one of the most useful modules that an Engineer or a Designer can try to test out and do some really good applications with it. Sold for a cheap price that any person could buy and try it out, it is widely used in many cellular phones.

In this blog, I will show really how to get this module up working. Also I will show how to make a cellular phone that can make phone calls, send SMS, make voice calls and log on the internet and much more. In other words we can say: Nokia watch out we are coming!

I am more than thankful to Alex Weber (http://tinkerlog.com) who helped me to make this module work and for me I will try to start with what Alex and SJ (http://note19.com) have ended with.

Dealing with this module GM862 is not that of an easy task and believe me, if you messed up in anything or did anything wrong, the module will burn and you will not be able to make it turn ON again.

So be caution when you work with this module as it is kind of tricky when you work with it.
I will post all the problems that I faced and you will most probably face when you get your leg into it.

In the end I will try to make this blog as a reference to everybody for dealing with this module and with other modules as well.

And if you have any questions regarding this module please don’t hesitate to ask.
Best of Luck!