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Gsm

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Nagarathna

New Member
HI,

I am trying to make my own mobile phone ,hence trying out all AT commands in the datasheet for simcom 300 modem.





the problem is i dont know how to store the message in order in sim memory or phone memory because in what i am doing the new nessage gets stored in the memory where there is no message i.e randomly .


plz give me a solution for this problem......
 

picbits

Well-Known Member
No chance you'll build a mobile phone, it's an extremely complex device.

Actually, for once I'm going to have to disagree with you there Bill.

If you use a GSM modem which it appears the OP has, you can have full phone functionality on many of the GSM Modems using AT commands.

I've recently "built" a complete GSM/GPS tracking setup using the Sony GM29 and a cheapo Taiwanese GPS module using a pair of 18F1320 to control it. I have full voice and text capabilities and can send/receive calls and texts.

It did however take me 2 days of RTFM before I got any good results.
 

Diver300

Well-Known Member
Most Helpful Member
It depends what you mean by "make your own mobile phone".

A mobile phone module, like the Telit devices, or, as far as I can tell the simcom 300, is all the tricky bits in one box.

You need to add a SIM card holder, aerial, battery or power supply, microphone and earphone along with some sort of controller to tell the module to dial, answer and hang up. It is quite a lot of work, but you really don't need to handle rf or any of the tricky protocols involved in a mobile phone network.

The SIM just wires straight to the module. 4 wires + earth and all you have to do is get the wires to the right places.

Dialing is just sending "ATD 0123456789" followed by carriage return, so a bit of programming, but not too much is needed.

www.sparkfun.com made a rotary dial phone into a cell phone:-
SparkFun Electronics

I made a Trimphone with a rotary dial into a cellphone in a similar way.
 

Nagarathna

New Member
Hi,

It'a not a big deal to make a mobile phone ,may be the hardware wouldnt look exactly like what we have in shops right now .

But i have completed 3/4 th of my work with a lowcost microcontroller to rx and send sms, outgoing call ,answer call, inbox ,newmsg etc along with the speakers.keypad.but with an ordinary 16*2 lcd.

This project will be upgraded later.......

it's simple plz to try it out once.
 

Diver300

Well-Known Member
Most Helpful Member
Except that's hardly 'making' a mobile phone - it's just buying a ready made one, lacking the keypad and display.

On that measure, Ford don't make all the Ford cars and Dell don't make computers, because a lot of cars with the Ford badge come with engines made by Peugeot, and Dell assemble computers with processors from Intel and batteries from Sony etc.

I make vehicle tracking devices, and I don't bother connecting up the voice circuit on the GSM module that I use. The same module can be put into a phone that anyone can use. The original poster is looking to build a device recognisable to and usable by anyone who had used a mobile phone, from a pile of bits that most people wouldn't know what they are for. He is even going to lay out circuit board and program a microcontroller.

All electronic projects rely heavily on the work of others. It may be just a transistor, battery and LED in a Joule Thief, or it could be microcontroller, C complier, voltage regulators etc etc in a larger project. We still regard such projects as "ours", because significant work has gone into them, and they are of use and their functionality is what we have made them to be.
 
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