I am connecting the GSM

[Apache79]

I am connecting the GSM Module to the MC with pins 2(tx), 3(rx) and 5(gnd). Should i connect the other pins of the RS232, or short them in any way?

 

I read somewhere that we have to give +9v to pin 7 and -9v to pin 4 of DB9. Is it true?

 

Please guide, 

 

Thanks