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Project to make a mobile phone

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Newbie level 4
Aug 6, 2007
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I have a project that to make a simple mobile phone by myself(dial and receive the call). May be i will add a display later.

I have got a GM862-QUAD module and GM862 Evaluation Board - RS232

I connected it to PC though Serial Cable(RS232).And it works fine when i send AT command by hyperterminal. So i am now starting to use microcontroller to operate it as a phone.

The problem is that i don't know how to start my project. My concept is, I need a keypad. Then connect the keypad to the microcontroller directly.Then connect the microcontroller to GM862.Is it right?Am i need to add something between keypad and microcontroller? Also microcontroller and GM862?

I want to know which microcontroller is good for this project? I would like to use C program. It seems that PIC and AVR are most popular. Is PIC16F877 enough for doing this?

Do there any sources and project that is similar to this?Can you send it to me as a reference?

I am really not familiar with it.It is my first time to do this kind of project.

use the NXP LPC microcontrollers
it ARM uC , Most phones use ARM uC!

You need to add some resistors between the keypad and the uc and nothing between the uC and the GM.
The gm has a RS232 port wich support 3v!

What is the advantages of LPC uC?

People said that AVR is good for C progamming, and i have used AT89C51 before. So i would like to use AVR if there are no big problem on AVR series. And is it good for me to use ATmega32 in this project?

The way I see it you only need a serial port to interface with your GSM module.
For the keypad you can use any IO ports of the microcontroller.

So not only can you use the AVR ATMega32 but you can also use your AT89C51 because both of them have a serial port and IO ports !!!

yes u can use AT89c51 too.
ur work will become keypad numbers,decode them in microcontroller,and then simply send AT commands according to dat...
so simple:D
and if module has data cable so u also need Rs232 with controller.

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