main.cpp

#include "credentials.h"
#include <Arduino.h> // for type definitions
#define TINY_GSM_MODEM_SIM800

#include <SoftwareSerial.h>
SoftwareSerial SerialAT(10, 11); // RX, TX

//#define DUMP_AT_COMMANDS
#define TINY_GSM_DEBUG Serial

#include <TinyGsmClient.h>

#ifdef DUMP_AT_COMMANDS
#include <StreamDebugger.h>
StreamDebugger debugger(SerialAT, Serial);
TinyGsm* modem = new TinyGsm(debugger);
#else
TinyGsm* modem = new TinyGsm(SerialAT);
#endif

class Gsm
{
public:
    Gsm(TinyGsm* modem)
        : modem(modem)
    {
    }

    bool sendSms(const char* text, const char* number)
    {
        bool res = modem->sendSMS(String(number), String(text));
        DBG("SMS:", res ? "OK" : "fail");
        return res;
    }

private:
    TinyGsm* modem;
};

Gsm gsm(modem);

void setup()
{

    Serial.begin(115200);
    delay(10);

    // Set your reset, enable, power pins here
    pinMode(8, OUTPUT);
    digitalWrite(8, LOW);
    delay(1000);
    digitalWrite(8, HIGH);

    // Set GSM module baud rate
    TinyGsmAutoBaud(SerialAT, 57600, 57600);

    // Restart takes quite some time
    // To skip it, call init() instead of restart()
    DBG("Initializing modem ...");
    if (!modem->restart())
    {
        delay(10000);
        return;
    }

    String modemInfo = modem->getModemInfo();
    DBG("Modem:", modemInfo);

    // Unlock your SIM card with a PIN
    modem->simUnlock(PIN);
    delay(5000);

    DBG("Waiting for network...");
    if (!modem->waitForNetwork())
    {
        delay(10000);
        return;
    }

    if (modem->isNetworkConnected())
    {
        DBG("Network connected");
    }
#if 1
    // Not working!
    gsm.sendSms(NUMBER, "Hallo Test");
#else
    // Working!
    bool res = modem->sendSMS(NUMBER, "Hello Test");
    DBG("SMS:", res ? "OK" : "fail");
#endif
}

void loop()
{
}