Question about Arduino Uno and ItedStudio 3G Shield ...

Hi, I’m trying to send commands to 3G Shield by Arduino Uno.
My jumper is set like 1.jpg
Here is my code, but I got strange response like 2.jpg
Anyone please tell me why, thanks!

#include <SoftwareSerial.h>
#define rxPin 0
#define txPin 1
SoftwareSerial mySerial(rxPin, txPin);//RX,TX

void setup() {

void loop() {
  if (mySerial.available())
  if (Serial.available())

You can't use D0 & D1 to talk to both Serial Monitor and the shield.

Move the jumpers to D2 & D3 and change your call to SoftwareSerial to reflect this.

Thank you!
Now I move the jumpers and modify my code like attachment and send ATcommand by serial monitor, but get nothing!

I can’t see your modified code.

Try exchanging the values of Rx, Tx in your code? SoftwareSerial mySerial(3,2) (You normally connect Rx to Tx and v.v.)