The Sim900 shield does not respond to AT commands sent through the Arduino IDE serial monitor.
Here is my sketch
#include <SoftwareSerial.h>
SoftwareSerial Sim900Serial(2, 3); //rx and tx
void setup()
{
Sim900Serial.begin(19200); // the GPRS baud rate
Serial.begin(19200); // the GPRS baud rate
}
void loop()
{
if (Sim900Serial.available())
Serial.write(Sim900Serial.read());
if (Serial.available())
Sim900Serial.write(Serial.read());
}
The code compiles with no errors.
With regard to jumper settings on the Sim900, GTx is linked with D2, while GRx is linked to D3.
Arduino Uno's pin 2,3 and GND are connected to Sim900's Tx,Rx and GND respectively.
I have powered the Sim900 with 7V 2A from the wall socket to Vin and GND of the GPRS Shield.
I should believe that the SIM900 is working perfectly fine because i have inserted the SIM card, and when the shield is powered up and switched on, it registers a network, as it blinks every 3 seconds, and also when i call the SIM on the shield from my mobile phone, it rings with no answer.
The only response that comes from the SIM900 shield is some funny unreadable characters, they only print on the serial monitor when Sim900 is switched on then off through the PWRKEY button.
I have attached images of my hardware connection as well as the serial monitor results
