Interfacing A9G with Arduino for AT commands testing

Question

I am trying to hook up to an A9G Pudding GSM board via an Arduino. I intend to use the onboard UART chip to facilitate TTL-UART conversion between PC and A9G.

I have initiated a software serial instance and using this to pass communication to/from the A9G and the Arduino.

Here's my code. However, all I'm getting is gibberish stuff. I've checked my connections, the link seems to exist but the encoding is mismatched. I'm communicating with the A9G at 115200 and my emulated serial is at 9600.

Could this be an issue?

#include <SoftwareSerial.h>

SoftwareSerial mySerial(10, 11); // RX, TX

void setup() {
  Serial.begin(9600); // Monitor baud rate
  mySerial.begin(57600); // Set to detected baud rate

  Serial.println("A9G Module Communication Test");
  
  // Send AT command with carriage return and line feed
  mySerial.print("AT\r\n");
  delay(1000); // Wait for response
}
void loop() {
  // Check if data is available from the A9G module
  if (mySerial.available()) {
    // Read the data from the A9G module
    while (mySerial.available()) {
      char c = mySerial.read();
      Serial.write(c); // Send it to the Serial Monitor
    }
  }

  // Check if data is available from the Serial Monitor
  if (Serial.available()) {
    // Read the data from the Serial Monitor
    while (Serial.available()) {
      char c = Serial.read();
      mySerial.write(c); // Send it to the A9G module
    }
  }
}

Here's the output on the serial monitor.

Answer 1

You can edit your code like this.

#include <SoftwareSerial.h>

SoftwareSerial mySerial(10, 11); // RX, TX

void setup() {
  Serial.begin(9600); // Monitor baud rate to match A9G
  mySerial.begin(115200); // Set to A9G baud rate

  Serial.println("A9G Module Communication Test");
  
  // Send AT command with carriage return and line feed
  mySerial.print("AT\r\n");
  delay(1000); // Wait for response
}

void loop() {
  // Check if data is available from the A9G module
  if (mySerial.available()) {
    // Read the data from the A9G module
    while (mySerial.available()) {
      char c = mySerial.read();
      Serial.write(c); // Send it to the Serial Monitor
    }
  }

  // Check if data is available from the Serial Monitor
  if (Serial.available()) {
    // Read the data from the Serial Monitor
    while (Serial.available()) {
      char c = Serial.read();
      mySerial.write(c); // Send it to the A9G module
    }
  }
}