//tambahin fungsi:
//fungsi send data to esp
boolean sendData(String command, char response[], const int timeout) {
    esp8266.print(command); // send the read character to the esp8266
    Serial.println(">"+command);
    long int time = millis();
    while( (time+timeout) > millis()) {
        while(esp8266.available()) {
            if(esp8266.find(response)){
                Serial.println("Response found");
                return true;
            }
            else if(esp8266.find("busy")){    //If device is busy...
                Serial.println("busy...");
                wifi_reset();
                waitResponse("ready",5000);
                return false;
            }
        }
    }
    Serial.println("Response NOT found");
    return false;
}

//## reset the esp8266 by digitalwrite pin
void wifi_reset(){
    digitalWrite(RST,LOW);
    delay(100);
    digitalWrite(RST,HIGH);
    delay(1000);
    Serial.println("##### ESP8266 Reset #####");
}


//kode untuk kirim data di main:
main(){
    ...
    String cmd="AT+CIPSEND=";
    cmd+= getStr.length();
    cmd+= "\r\n";

    //timeout 10000
    if(sendData(cmd,">",10000)){
        //berhasil
    } else {
        //gagal
        Serial.println("connection timeout");
        sendData("AT+CIPCLOSE\r\n","OK",1000);
        return;
    }
    ...
}