sample code and interfacing instruction for m590 gsm module

See documentation: http://guides.cyntech.co.uk/raspberry-pi/tutorial/soldering-the-m590-gsmgprs-module/

Pins :

+5v > 5v power supply in
GND > Ground – 0v
I > Ring – Output (Will pulse low for an incoming call or SMS)
T > Transmit (3.3v logic)
R > Receive (3.3v logic)
V > Voltage after diode (Around 4.45v – M590 maximum is 4.5v)
K > On/Off (Latched input – Pull low to turn on, pull low again to turn module off)
G > Ground – 0v

Note :
Connect a 1000uF capacitor between 5V and GND. THIS IS IMPORTANT.
Generally Default baud rate is 57600