Waveshare SIM7600G-H AT Commands on Serial Port

[ankitvirdi]

Hello,

I am trying to learn more about GSM modules so I can eventually use them for my IOT projects. I have a Waveshare SIM7600G-H Module.

I managed to get the UART between Arduino UNO and the GSM module established by following the instructions on the wiki.

I did change a small part in the library SoftwareSerial mySerial(3,4);//RX=3,TX=4 as in the orginal library the pins are 2 and 3 which clash with the pwr pin, being 2.

Here's my code

#include "Waveshare_SIM7600.h"

// Pin definition
int POWERKEY = 2;

char phone_number[] = "7380XXXXXX";      //********** change it to the phone number you want to call
char text_message[] = "www.waveshare.com";      //

void setup() {
  sim7600.PowerOn(POWERKEY);
  sim7600.SendingShortMessage(phone_number,text_message);
  sim7600.ReceivingShortMessage();
}


void loop() {

}

Here what I get on the serial monitor: -

I want to send AT commands from my Serial Monitor to debug, however thats on USB which would go to Serial, and GSM Module communicates via myserial, is there a way to echo data to and fro?

[ankitvirdi]

Added the following code in the loop:-

void loop() {
    while(Serial.available()){
      sim7600.sendATcommand(Serial.read(), “OK”, 1000);
    }
}

this should work, but it doesn't I don't know what I am missing

[red_car]

@ankitvirdi

this should work, but it doesn't I don't know what I am missing

Serial.read() returns a single character... so you are currently sending multiple single character commands to the SIM7600... that won't work.

Try...

      sim7600.sendATcommand(Serial.readString(), “OK”, 1000);

[ankitvirdi]

You are right, i figured that and tried to send string that threw an error

Cause in the header the function declaration is

uint8_t sendATcommand(const char* ATcommand, const char* expected_answer, unsigned int timeout);

Here's the error:

Compilation error: no matching function for call to ‘Sim7x00::sendATcommand(String, const char [3], int)’

[red_car]

Try converting to a C string...
sim7600.sendATcommand(Serial.readString().c_str(), “OK”, 1000);

[ankitvirdi]

Compiles now

However, Can't use Serial.avaliable() in the loop() cause the SIM7600 responses are on the Serial Bus as well.

OKAT+CMGR=1

+CMGR:AT

OKAT+CREG?

+CREG: 0,1Setting SMS mode...
AT+CMGF=1

OKSending Short Message
AT+CMGS="7380xxxxxx"

>
+CMS ERROR: Unknown error
error 
Setting SMS mode...
AT+CMGF=1

OKAT+CPMS="QM","SM","SM!


+ChS*'�b��b�b��b�b��j

OKAT+CMGR=1

+CMGR:

[red_car]

I use the following sketch for sending commands to my SIM7600 (different module). You might need to set the power on pin on yours.

#include <SoftwareSerial.h>

#define BAUD 9600

SoftwareSerial softSerial (3, 4);  // Rx, Tx as required.


void setup()
{
  Serial.begin(BAUD);
  softSerial.begin(BAUD);

  Serial.print("Ready @ ");
  Serial.print(BAUD);
  Serial.println(" baud");
}


void loop()
{
  while (Serial.available() > 0)
  {
    char c = Serial.read();

    if (c == '*')
        softSerial.write(0x1A);  
      else
        softSerial.write(c);
  }

  while (softSerial.available() > 0)
    Serial.write(softSerial.read());
}

[ankitvirdi]

Thanks for your help, this should work, I dont understand whats up with this module, NET LED is flashing quickly so its connected to the network, I managed to send myself an SMS if I hardcode it. Nothing works on serial tho.

I added PowerOn to your sketch

#include <SoftwareSerial.h>

#define BAUD 115200
#define POWERKEY 2
SoftwareSerial softSerial (3, 4);  // Rx, Tx as required.
void PowerOn();

void setup()
{
  Serial.begin(BAUD);
  softSerial.begin(BAUD);
  PowerOn();
  Serial.print("Ready @ ");
  Serial.print(BAUD);
  Serial.println(" baud");
}


void loop()
{
  while (Serial.available() > 0)
  {
    char c = Serial.read();

    if (c == '*')
        softSerial.write(0x1A);  
      else
        softSerial.write(c);
  }

  while (softSerial.available() > 0)
    Serial.write(softSerial.read());
}

void PowerOn() {
    pinMode(POWERKEY, OUTPUT); // power on pulse
    digitalWrite(POWERKEY, HIGH);
    delay(500);
    digitalWrite(POWERKEY, LOW);

}

I dont get any response to AT

[red_car]

Software serial won't work at anything more than about 38400.

Do you know what baud rate is the module currently set to?

[ankitvirdi]

Its set to 115200, hold on let me try and change that.

[ankitvirdi]

@red_car I changed the module Baud to 9600, still can't get it to respond to me on Serial

[ankitvirdi]

Only Seems to respond to sim7600.sendATcommand()

[red_car]

Not sure why. Try powering on before you open the serial connection.

[ankitvirdi]

If power on before openning the terminal I get the auto responses on power on.

but no response to the AT commands

[red_car]

Ok that's something... looks like you are at least receiving messages. I presume if you send an SMS to the SIM7600 you also receive messages?

What line ending are you using in the Serial Monitor? Try "Both NL & CR".

[ankitvirdi]

Sweet! That did it, Cheers. Thanks for the help.