GSM SIM900A MINI V3.8.2

Hello there...
I am using SIM900A GSM module with Arduino Uno when I tested by AT comm. there is no answer back like 'OK' or 'error please help me with that.
External power source 5v 2A to gsm
5vt >> pin 9
5vr >> pin 10
GR >> ard. GR

You will have to elaborate a little and narrow down your request. Provide your source code, the input and the output. Tell us about your setup.

#include <SoftwareSerial.h>

/*
GSM Tx <–> digital pin 9
GSM Rx <–> digital pin 8
*/
SoftwareSerial gsmSerial(9,10);

void setup()
{
Serial.begin(9600); // Setting the baud rate of Serial Monitor (Arduino)
gsmSerial.begin(9600); // Setting the baud rate of GSM Module
delay(100);
}

void loop()
{
while (Serial.available()) gsmSerial.write(Serial.read());
while (gsmSerial.available()) Serial.write(gsmSerial.read());
}

just the GSM input and output . I want to test it with AT comm. but no response

ibrahim_77:
#include <SoftwareSerial.h>
/*
GSM Tx <–> digital pin 9
GSM Rx <–> digital pin 8
*/
SoftwareSerial gsmSerial(9,10);

void setup()
{
Serial.begin(9600); // Setting the baud rate of Serial Monitor (Arduino)
gsmSerial.begin(9600); // Setting the baud rate of GSM Module
delay(100);
}

void loop()
{
while (Serial.available()) gsmSerial.write(Serial.read());
while (gsmSerial.available()) Serial.write(gsmSerial.read());
}

Did you write this? Do you know what it’s doing?
This code prints to the serial port what is received by the software serial port and to the software serial port what is received by the serial port.
How are you sending AT commands? Where are you looking for a response?

/*
    GSM Tx <--> digital pin 9
    GSM Rx <--> digital pin 8
*/
SoftwareSerial gsmSerial(9,10);

Why did you connect the module RX to pin 8?

The module RX should be connected to Pin 10 which is the Arduino SS TX According to the SoftwareSerial constructor

SoftwareSerial mySerial (rxPin, txPin);