TEST MODULE SIM 4G

#include <HardwareSerial.h>
#include <WiFi.h>

#define simSerial                 Serial0  
#define MCU_SIM_BAUDRATE          115200
#define MCU_SIM_TX_PIN            43 
#define MCU_SIM_RX_PIN            44 
#define MCU_SIM_EN_PIN            41
#define PHONE_NUMBER            "" //SĐT của bạn

void sim_at_wait() {
    delay(500);
    while (simSerial.available()) {
        Serial.write(simSerial.read());
    }
}

bool sim_at_cmd(String cmd) {
    Serial.print("Sending command: ");
    Serial.println(cmd);
    simSerial.println(cmd);
    delay(500); // 
    sim_at_wait();
    return true;
}

bool sim_at_send(char c) {
    simSerial.write(c);
    return true;
}

void sent_sms() {
    sim_at_cmd("AT+CMGF=1"); 
    String temp = "AT+CMGS=\"";
    temp += PHONE_NUMBER;
    temp += "\"";
    sim_at_cmd(temp);
    sim_at_cmd("hello from TDLOGY");
    sim_at_send(0x1A); 
} 




void setup() {
   pinMode(MCU_SIM_EN_PIN, OUTPUT);
    digitalWrite(MCU_SIM_EN_PIN, HIGH); 
    delay(500);   
    Serial.begin(115200);
    Serial.println("\n\n\n\n-----------------------\nSystem started!!!!");
    delay(8000);
    simSerial.begin(MCU_SIM_BAUDRATE, SERIAL_8N1, MCU_SIM_RX_PIN, MCU_SIM_TX_PIN);
    Serial.println("Checking AT command...");
    sim_at_cmd("AT");
    Serial.println("Getting product info...");
    sim_at_cmd("ATI");
    Serial.println("Checking SIM status...");
    sim_at_cmd("AT+CPIN?");
    Serial.println("Checking signal quality...");
    sim_at_cmd("AT+CSQ");
    Serial.println("Getting IMSI...");
    sim_at_cmd("AT+CIMI");
    sent_sms();
}
void loop() {     
    if (Serial.available()) {
        char c = Serial.read();
        simSerial.write(c);
    }
   
    
}

Đây là màn hình monitor sau khi code được nạp

CSQ là chất lượng sóng.