ESP32 SIM7600 Cellular Modem Interface using Arduino IDE

const char apn[]      = "airtelgprs.com";

#define MODEM_RST            5
#define MODEM_PWKEY          4
#define MODEM_POWER_ON       36
#define MODEM_TX             14
#define MODEM_RX             33

// Debug console
#define SerialMon Serial
// AT command serial
#define SerialAT Serial1

// Configure TinyGSM library
#define TINY_GSM_MODEM_SIM7600      // Modem is SIM7600
#define TINY_GSM_RX_BUFFER   1024   // Set RX buffer to 1Kb
#define TINY_GSM_DEBUG SerialMon

#include <TinyGsmClient.h>

TinyGsm modem(SerialAT);
// TinyGSM Client for Internet connection
TinyGsmClient client(modem);

void setup() {
  // Set modem reset, enable, power pins
  pinMode(MODEM_PWKEY, OUTPUT);
  pinMode(MODEM_RST, OUTPUT);
  pinMode(MODEM_POWER_ON, OUTPUT);
  digitalWrite(MODEM_PWKEY, LOW);
  digitalWrite(MODEM_RST, HIGH);
  digitalWrite(MODEM_POWER_ON, HIGH);

  // Set GSM module baud rate and UART pins
  SerialAT.begin(115200, SERIAL_8N1, MODEM_RX, MODEM_TX);
  delay(3000);

  SerialMon.begin (115200);
  SerialMon.println("Restarting + Initializing modem...");
  modem.restart();
}

void loop() {
  SerialMon.println("Waiting for link to be ready...");
  SerialMon.println("Connecting to APN...");
  SerialMon.println(apn);
  if (!modem.gprsConnect(apn))
  {
    SerialMon.println("Failed to connect (APN)");
  }
  else 
  {
    SerialMon.println("Connected (APN)!");
  }

  // Connect to pcbartists.com
  if (client.connect ("pcbartists.com", 80))
  {
    SerialMon.println("Connected!");
  }
  else
  {
    SerialMon.println("Could not connect to pcbartists.com");
    while (1)
      delay (10);
  }

  SerialMon.println ("Sending GET request to pcbartists.com/test.txt...");

  // Send a GET request
  client.println ("GET /test.txt HTTP/1.1");
  client.println ("Host: pcbartists.com");
  client.println ("Connection: close");
  client.println ();
  
  // Print response from server, including response headers
  SerialMon.println ("### Server response: ###");
  while (client.connected() || client.available())
  {
    if (client.available())
    {
      char c = client.read();
      SerialMon.print (c);
    }
  }
  SerialMon.println ("");
  SerialMon.println ("### End of response ###");

  client.stop();
  SerialMon.println ("Disconnected from pcbartists.com!");

  // Do nothing
  while (1)
    delay (10);
}