#include <SoftwareSerial.h>

#define RX_PIN 26
#define TX_PIN 27
#define POWER_PIN 4
#define BAUD_RATE 115200
#define LED_PIN 12

SoftwareSerial sim(RX_PIN, TX_PIN);

bool isModemPoweredOn() {
  sim.println("AT");
  delay(1000);
  if (sim.find("OK")) {
    return true;
  } else {
    return false;
  }
}

void setup() {
  Serial.begin(BAUD_RATE);
  sim.begin(BAUD_RATE);
  pinMode(POWER_PIN, OUTPUT);
  pinMode(LED_PIN, OUTPUT);
  Serial.println("Powering off modem.");
  digitalWrite(POWER_PIN, LOW);
  digitalWrite(LED_PIN, LOW);
  delay(1000);
  Serial.println("Powering on modem.");
  digitalWrite(POWER_PIN, HIGH);
  digitalWrite(LED_PIN, HIGH);
  delay(10000);
  
  // Check if modem is powered on
  if (isModemPoweredOn()) {
    Serial.println("Modem is powered on and ready.");
  } else {
    Serial.println("Modem is not responding to AT commands. Please check power connection and pin configuration.");
  }
}

void loop() {
  // Check if modem is registered to the network
  sim.println("AT+CREG?");
  delay(1000);
  if (sim.find("+CREG: 0,1") || sim.find("+CREG: 0,5")) {
    Serial.println("Modem registered to the network.");
    
    // Set SMS mode to text mode
    sim.println("AT+CMGF=1");
    delay(1000);
    
    // Send SMS message
    sim.println("AT+CMGS=\"+4799999999\"");
    delay(1000);
    sim.println("LilyGO-T-SIM7000G booted up!");
    delay(100);
    sim.write(26);
    delay(1000);
  } else {
    Serial.println("Modem not registered to the network. Trying to connect...");
    
    // Configure APN
    sim.println("AT+CGDCONT=1,\"IP\",\"telia\"");
    delay(1000);
    
    // Set modem to automatically select the network and start the GPRS and LTE services
    sim.println("AT+COPS=0");
    delay(5000);
    
    // Check if modem is registered to the network
    sim.println("AT+CREG?");
    delay(1000);
    if (sim.find("+CREG: 0,1") || sim.find("+CREG: 0,5")) {
      Serial.println("Modem connected to the network.");
      
      // Set SMS mode to text mode
      sim.println("AT+CMGF=1");
      delay(1000);
      
      // Send SMS message
      sim.println("AT+CMGS=\"+479999999\"");
      delay(1000);
      sim.println("LilyGO-T-SIM7000G booted up!");
      delay(100);
      sim.write(26);
      delay(1000);
    } else {
      Serial.println("Modem could not connect to the network.");
    }
  }
  
  delay(1000);
}

// https://github.com/Xinyuan-LilyGO/LilyGO-T-SIM7000G/tree/master/examples

#define TINY_GSM_MODEM_SIM7000 //Defines model of the modem.
#define TINY_GSM_RX_BUFFER 1024 // Set RX buffer to 1Kb
#define SerialAT Serial1 //Makes us able to communicate directly with the SIM-card with SerialAT-commands.

// See all AT commands, if wanted
//#define DUMP_AT_COMMANDS //If you want to debug, then remove // and connect to the serial cable.

// set GSM PIN, if any
#define GSM_PIN ""	//I don't have any PIN at the SIM.

// Your GPRS credentials, if any
const char apn[]  = "telia";     //SET TO YOUR APN
const char gprsUser[] = "";
const char gprsPass[] = "";

#include <TinyGsmClient.h>
#include <SPI.h>
#include <SD.h>
#include <Ticker.h>

#ifdef DUMP_AT_COMMANDS  // if enabled it requires the streamDebugger lib
#include <StreamDebugger.h>
StreamDebugger debugger(SerialAT, Serial); //sends output from SerialAT to Serial.
TinyGsm modem(debugger);
#else
TinyGsm modem(SerialAT);
#endif

#define uS_TO_S_FACTOR 1000000ULL  // Conversion factor for micro seconds to seconds
#define TIME_TO_SLEEP  60          // Time ESP32 will go to sleep (in seconds)

#define UART_BAUD   115200		//The SIM7000G module requires 115200 BAUD.
#define PIN_DTR     25
#define PIN_TX      27
#define PIN_RX      26
#define PWR_PIN     4

#define SD_MISO     2
#define SD_MOSI     15
#define SD_SCLK     14
#define SD_CS       13
#define LED_PIN     12
#define CELLULAR    true


int counter, lastIndex, numberOfPieces = 24;
String pieces[24], input;





void setup() {
//Sets the BAUD rate to 115200 from UART_BAUD
Serial.begin(UART_BAUD);

//Begin SD-car discovery and mount.
SPI.begin(SD_SCLK, SD_MISO, SD_MOSI, SD_CS);
if (!SD.begin(SD_CS)) {
	Serial.println("No SD-card present!");
} else {
	//If SD-card present.
    uint32_t cardSize = SD.cardSize() / (1024 * 1024);
    String str = "SDCard Size: " + String(cardSize) + "MB";
}
//End SD-card dicovery and mount.

cellularconnect();
}



void cellularconnect() {
  if (CELLULAR) {
    //Sets PIN for LED and modem off.
    //The LED is the built-in blue.
    pinMode(LED_PIN, OUTPUT);
    pinMode(PWR_PIN, OUTPUT);
    digitalWrite(LED_PIN, HIGH); //HIGH does the opposite at this pin.
    digitalWrite(PWR_PIN, HIGH); //HIGH does the opposite at this pin.

    //Waiting for 5 seconds before proceeding.
    delay(5000);

    //Turning on the modem.
    digitalWrite(PWR_PIN, LOW); //LOW does the opposite at this pin.
    
    //waiting for 5 seconds before proceeding.
    delay(5000);

      //Starts serial session with the modem.
      SerialAT.begin(UART_BAUD, SERIAL_8N1, PIN_RX, PIN_TX);
      if(!modem.init()) {
        Serial.println("Modem did not init. Try rebooting your device by plugging out power!");
      } else {
        if( GSM_PIN && modem.getSimStatus() != 3 ) {
          modem.simUnlock(GSM_PIN); // If the SIM is locked, this will unlock with the PIN defined in the variables.
        }
        modem.sendAT("+SGPIO=0,4,1,0");	//This turns off the GPS-module.
        modem.sendAT("+CFUN=0 ");		//This disables some functions on the modem, for example phone calls. Power saving.
        modem.setNetworkMode(2);		//2 = Automatic, LTE or GPRS.
        modem.setPreferredMode(3);
        delay(5000);
        modem.sendAT("+CFUN=1 ");
        modem.sendAT("+CGDCONT=1, \"IPV4V6\",\"" + String(apn) + "\", \"0.0.0.0\",0,0,0,0"); //I know the modem profile number 1 because the original script gave me them in a very huge loop-script.
        modem.sendAT("+CGDCONT=13, \"IPV4V6\",\"" + String(apn) + "\", \"0.0.0.0\",0,0,0,0"); //I know the modem profile number 13 because the original script gave me them in a very huge loop-script.
        modem.sendAT("+CGDCONT=3, \"IPV4V6\",\"" + String(apn) + "\", \"0.0.0.0\",0,0,0,0"); //I know the modem profile number 3 because the original script gave me them in a very huge loop-script.
        delay(5000);
        if (modem.isNetworkConnected()) {
          modem.gprsConnect(apn, gprsUser, gprsPass);
          if (modem.isGprsConnected()) { //Telling us if we are connected or not.
            digitalWrite(LED_PIN, LOW); //Turns on the blue LED to confirm we are connected.
            String name = modem.getModemName();
            String modemInfo = modem.getModemInfo();
            String ccid = modem.getSimCCID();
            String imei = modem.getIMEI();
            String cop = modem.getOperator();
            IPAddress local = modem.localIP();
            int csq = modem.getSignalQuality();
            Serial.println("Modem name: " + name + "Modem info: " + modemInfo + "CCID: " + ccid + "IMEI: " + imei + "Operator: " + cop + "Local IP: " + local + "Signal: " + csq);
			//At this point, we are connected.
          } else {
			//If the connection failed, the LED will blink 2 times and turn off. You will probably not see this error because the script will break before this point.
            Serial.println("Not connected!");
            digitalWrite(LED_PIN, LOW);
            delay(50);
            digitalWrite(LED_PIN, HIGH);
            delay(50);
            digitalWrite(LED_PIN, LOW);
            delay(50);
            digitalWrite(LED_PIN, HIGH);
        }
      }
    }
  }
}


void loop() {
SerialAT.println("AT+CPSI?");     //Get connection type and band
    if (SerialAT.available()) {
        String r = SerialAT.readString();
 //       Serial.println(r);
    }
	
String name = modem.getModemName();
String modemInfo = modem.getModemInfo();
String ccid = modem.getSimCCID();
String imei = modem.getIMEI();
String cop = modem.getOperator();
IPAddress local = modem.localIP();
int csq = modem.getSignalQuality();

Serial.println("Modem name: " + name + "Modem info: " + modemInfo + "CCID: " + ccid + "IMEI: " + imei + "Operator: " + cop + "Local IP: " + local + "Signal: " + csq);
delay(60);

//The loop is printing out modem name, info, IMEI, operator, local ip and signal strength to the serial console every 60 milliseconds.
}

#define TINY_GSM_MODEM_SIM7000 //Defines model of the modem.
#define TINY_GSM_RX_BUFFER 1024 // Set RX buffer to 1Kb
#define SerialAT Serial1 //Makes us able to communicate directly with the SIM-card with SerialAT-commands.

// See all AT commands, if wanted
//#define DUMP_AT_COMMANDS //If you want to debug, then remove // and connect to the serial cable.

// set GSM PIN, if any
#define GSM_PIN ""

// Your GPRS credentials, if any
const char apn[]  = "telia";     //SET TO YOUR APN
const char gprsUser[] = "";
const char gprsPass[] = "";

unsigned long cellularConnectionStepMillis;
unsigned int cellularConnectionStep;

#include <TinyGsmClient.h>
#include <SPI.h>
#include <SD.h>
#include <Ticker.h>


#ifdef DUMP_AT_COMMANDS  // if enabled it requires the streamDebugger lib
#include <StreamDebugger.h>
StreamDebugger debugger(SerialAT, Serial); //sends output from SerialAT to Serial.
TinyGsm modem(debugger);
#else
TinyGsm modem(SerialAT);
#endif

#define UART_BAUD   115200
#define PIN_DTR     25
#define PIN_TX      27
#define PIN_RX      26
#define PWR_PIN     4

#define SD_MISO     2
#define SD_MOSI     15
#define SD_SCLK     14
#define SD_CS       13
#define LED_PIN     12

TinyGsmClient client(modem);


//The array below is the 28 commands that needs to be sent to the modem to initialize it and connect it to GPRS / LTE, then get a IP-address.
//I haven't a PIN-code, so the command to unlock the SIM-card is not in the array. If you need it, the command is:
//AT+CPIN=XXXX
//And it should be sent after the AT+CPIN? command.

String cellularConnectCommands[] = {
  "AT",
  "AT+CPIN?",
  "AT+COPS=0",
  "AT+CNMP=0",
  "AT+CNMB=3",
  "AT+SGPIO=0,4,1,1",
  "AT+CGDCONT=1, \"IPV4V6\",\"" + String(apn) + "\", \"0.0.0.0\",0,0,0,0",
  "AT+CGDCONT=13, \"IPV4V6\",\"" + String(apn) + "\", \"0.0.0.0\",0,0,0,0",
  "AT+CGDCONT=3, \"IPV4V6\",\"" + String(apn) + "\", \"0.0.0.0\",0,0,0,0",
  "AT+CGREG?",
  "AT+CIPSHUT",
  "AT+CGATT=0",
  "AT+SAPBR=0,1",
  "AT+SAPBR=3,1,\"Contype\",\"GPRS\"",
  "AT+SAPBR=3,1,\"APN\",\"telia\"",
  "AT+CGDCONT=1,\"IP\",\"telia\"",
  "AT+CGATT=1",
  "AT+CGACT=1,1",
  "AT+SAPBR=1,1",
  "AT+SAPBR=2,1",
  "AT+CIPMUX=1",
  "AT+CIPQSEND=1",
  "AT+CIPRXGET=1",
  "AT+CSTT=\"telia\",\"\",\"\"",
  "AT+CIICR",
  "AT+CIFSR;E0",
  "AT+CEREG?",
  "AT+CGATT?"
};

/////////////////////////////////////// VOID SETUP AND VOID LOOP
void setup() {
//Sets the BAUD rate to 115200 from UART_BAUD
Serial.begin(UART_BAUD);

//Begin SD-car discovery and mount.
SPI.begin(SD_SCLK, SD_MISO, SD_MOSI, SD_CS);
if (!SD.begin(SD_CS)) {
	Serial.println("No SD-card present!");
} else {
        uint32_t cardSize = SD.cardSize() / (1024 * 1024);
        String str = "SDCard Size: " + String(cardSize) + "MB";
}
//End SD-card dicovery and mount.

//Turn off / on modem to initialize it.
pinMode(PWR_PIN, OUTPUT);
pinMode(LED_PIN, OUTPUT);

digitalWrite(PWR_PIN, LOW);
digitalWrite(LED_PIN, LOW); //LOW means that the LED is turned ON. This built-in PIN does the opposite of LOW / HIGH.

delay(1200); //According to original script, the modem have to be turned on after 1,2 seconds.

digitalWrite(PWR_PIN, HIGH);
digitalWrite(LED_PIN, HIGH); //HIGH means that LED is turned off. This built-in PIN does the opposite of LOW / HIGH.

//Starts a serial connection with the modem.
SerialAT.begin(UART_BAUD, SERIAL_8N1, PIN_RX, PIN_TX); //Starting a serial session with the modem.

//Sets variables for the loop.
cellularConnectionStep = 1;
cellularConnectionStepMillis = millis();

}



void loop() {

//The if-statement below do run all commands in the array, and do check if the modem does respond to it, but not what the response is. This script does not do a error check, but this script will repeat the steps if the modem does not respond, until it responds, then it will go to next step.

  if((cellularConnectionStep > 0) && (millis () - cellularConnectionStepMillis > 2000)) {
    SerialAT.println(cellularConnectCommands[cellularConnectionStep - 1]);
    if(SerialAT.available()) {
        cellularConnectionStepMillis = 0;
        cellularConnectionStep += 1;
        if(cellularConnectionStep == 29) {
          cellularConnectionStep = 0;
          cellularConnectionStepMillis = 0;
        }
    Serial.println(cellularConnectionStep);
    }
        cellularConnectionStepMillis = millis();
  }


//The if statement below is actual when the loop above have finished all commands in the array.
    if((cellularConnectionStep == 0) && (millis () - cellularConnectionStepMillis > 10000)) {
        String name = modem.getModemName();
        String modemInfo = modem.getModemInfo();
        String ccid = modem.getSimCCID();
        String imei = modem.getIMEI();
        String cop = modem.getOperator();
        IPAddress local = modem.localIP();
        int csq = modem.getSignalQuality();
        Serial.println("Modem name: " + name + " Modem info: " + modemInfo + " CCID: " + ccid + " IMEI: " + imei + " Operator: " + cop + " Local IP: " + local + " Signal: " + csq);
        cellularConnectionStepMillis = millis();
    }
}