ModemClass.cpp


/*
   Class example for communicating the the Telstra LPWAN modem.
*/

#include <stdlib.h>
#include <stdarg.h>

#include <Arduino.h>

// To have the Regexp.h line below work, firstly
// 1) Download the file http://gammon.com.au/Arduino/Regexp.zip
// 2) Within the Arduino IDE, use Sketch > Include Library > Add .ZIP Library
//    and select the Regexp.zip file you just downloaded
// #include "Regexp.h"

#include "ModemClass.h"

SoftwareSerial _LoRaSerial(8, 9);
//AltSoftSerial _LoRaSerial;

LoRaModem::LoRaModem()
{
  _LoRaSerial.begin(9600);
  _LoRaSerial.setTimeout(100);
};

/******************
   _sendSerial
   Generic private method for sending serial data to the modem, used by everything.
*/

void LoRaModem::_sendSerial(String message)
{
  DEBUG_PRINT("> " + message);
  _LoRaSerial.read();
  _LoRaSerial.println(message);
};

/******************
   _checkresponse
   Generic private method for reading back from the modem, and qualifying the response against a Regex
*/

int LoRaModem::_checkresponse(const char* checkVal, int call_timeout = rx_timeout, int _trim = 0)
{
  modemResp[0] = 0;

  unsigned long startTime = millis();

  int i = 0;

  while (i < rx_buffer - 1)
  {

    if (_trim == 1)
    {
      // _LoRaSerial.find("Wait"); // toss the verbosity.
    }

    int rxcount = _LoRaSerial.readBytes(&modemResp[i], rx_buffer - i);
    i += rxcount;
    modemResp[i] = 0;

    if (millis() - startTime > call_timeout)
    {
      _rspMs.Target(modemResp, i);
      char result = _rspMs.Match(checkVal, 0);
      if (result == REGEXP_MATCHED)
      {
        //Terminate the string
        DEBUG_PRINT(modemResp);
        return 0;
      }
      else
      {
        DEBUG_PRINT(F("Unexpected or no response"));
        DEBUG_PRINT(modemResp);
        return 1;
      }
    }
  }
};


// Check AT, just check if the modem is alive
int LoRaModem::checkAT() {
  _sendSerial("AT");
  return _checkresponse("%+AT: OK", rx_timeout_fast);
};

// Find out current modem ID
int LoRaModem::checkID() {
  _sendSerial("AT+ID");
  if (_checkresponse("%+ID: DevAddr (.+)\r\n%+ID: DevEui (.+)\r\n%+ID: AppEui (.+)"))
  {
    return 1;
  }
  _rspMs.GetCapture (DevAddr, 0);
  _rspMs.GetCapture (DevEui, 1);
  _rspMs.GetCapture (AppEui, 2);

  String temp_s;
  temp_s = String(DevAddr);
  temp_s.replace(":", " ");
  temp_s.toCharArray(DevAddr, 12);

  temp_s = String(DevEui);
  temp_s.replace(":", " ");
  temp_s.toCharArray(DevEui, 24);

  temp_s = String(AppEui);
  temp_s.replace(":", " ");
  temp_s.toCharArray(AppEui, 24);

};

// Find out current network data class
int LoRaModem::getDR() {
  _DR[0] = '0';
  _sendSerial("AT+DR");
  if (_checkresponse("%+DR: DR(.+)\r\n", rx_timeout_fast))
  {
    return 1;
  }
  _rspMs.GetCapture (_DR, 0);

  return _DR[0];
};


// Set DR, where DR is "DR0", "DR1", "DR2" or "DR3"
int LoRaModem::setDR(String DR) {
  _sendSerial("AT+DR=" + DR);
  if (_checkresponse("%+DR: DR.+", rx_timeout_fast))
  {
    return 1;
  }

  return 0;
};

// Disable ADR
int LoRaModem::disableADR() {
  _sendSerial("AT+ADR=OFF");
  if (_checkresponse("%+ADR: OFF.+", rx_timeout_fast))
  {
    return 1;
  }

  return 0;
};

// Set the modem ID
int LoRaModem::setID(String addr, String dev) {
  _sendSerial("AT+ID=DevAddr,\"" + addr + "\"");
  if (_checkresponse("%+ID: DEVADDR .+", rx_timeout_fast))
  {
    return 1;
  }

  _sendSerial("AT+ID=DevEui,\"" + dev + "\"");
  if (_checkresponse("%+ID: DEVEUI .+", rx_timeout_fast))
  {
    return 1;
  }

  return 0;
};

// Set the modem keys
int LoRaModem::setKeys(String NWSKey, String AppSKey) {
  _sendSerial("AT+KEY=NWKSKEY,\"" + NWSKey + "\"");
  if (_checkresponse("%+KEY: NWKSKEY .+", rx_timeout_fast))
  {
    return 1;
  }

  _sendSerial("AT+KEY=APPSKEY,\"" + AppSKey + "\"");
  if (_checkresponse("%+KEY: APPSKEY .+", rx_timeout_fast))
  {
    return 1;
  }

  return 0;

};

// Set the payload port #
int LoRaModem::setPort(String portNum) {
  _sendSerial("AT+PORT=" + portNum);
  if (_checkresponse("%+PORT: OK.+", rx_timeout_fast))
  {
    return 1;
  }

  return 0;

};

// Send a message, don't expect an ACK
int LoRaModem::Msg(String message) {
  _sendSerial("AT+MSG=\"" + message + "\"");

  if (_checkresponse(".+MSG: Done"))
  {
    return 1;
  }

  return 0;
};

// Send a message, expect an ACK
int LoRaModem::cMsg(String message) {
  _sendSerial("AT+CMSG=\"" + message + "\"");

  if (_checkresponse(".+ACK Received.+CMSG: Done"))
  {
    return 1;
  }

  return 0;
};

// Send a HEX string message, don't expect an ACK
int LoRaModem::MsgHEX(String message) {
  _sendSerial("AT+MSGHEX=\"" + message + "\"");

  if (_checkresponse(".+MSGHEX: Done"))
  {
    return 1;
  }

  return 0;
};

// Send a HEX string message, expect an ACK
int LoRaModem::cMsgHEX(String message) {
  _sendSerial("AT+CMSGHEX=\"" + message + "\"");

  if (_checkresponse(".+ACK Received.+CMSGHEX: Done"))
  {
    return 1;
  }

  return 0;
};


/******************
   cMsgBytes
   Send a byte array message, expect an ACK
*/
int LoRaModem::cMsgBytes(uint8_t * bytes, int16_t length) {

  _LoRaSerial.read();
  _LoRaSerial.print("AT+CMSGHEX=\"");

  do {
    prnt("%02x", *bytes++);
  } while (--length);

  _LoRaSerial.println("\"");

  if (_checkresponse(".+ACK Received.+CMSGHEX: Done"))
  {
    return 1;
  }

  return 0;
};

int LoRaModem::lowPower() {
  _sendSerial("AT+LOWPOWER");

  if (_checkresponse(".+LOWPOWER: SLEEP.+", rx_timeout_fast))
  {
    return 1;
  }
  return 0;
};

// Reset the modem
int LoRaModem::Reset() {
  _sendSerial("AT+RESET");

  if (_checkresponse(".+RESET: OK.+ 1.7.1"))
  {
    return 1;
  }
  return 0;
};

// Extract the downlink payload (if any) and convert to ASCII
String LoRaModem::getAscii() {

  char buf[100];

  char result = _rspMs.Match(".+RX: \"(.+)\".+", 0);
  if (result == REGEXP_MATCHED)
  {
    _rspMs.GetCapture (buf, 0);

    String ASCIIValue = "";

    for (int i = 0; i < strlen(buf) + 1; i += 3) {
      char val = buf[i] > 0x39 ? (buf[i] - 55) * 16 : (buf[i] - '0') * 16;
      val += buf[i + 1] > 0x39 ? (buf[i + 1] - 55) : (buf[i + 1] - '0');
      ASCIIValue += val;
    }
    return ASCIIValue;
  }
  else
  {
    DEBUG_PRINT(F("No ASCII payload..."));
    return "";
  }
};

void LoRaModem::prnt(char * fmt, ... ) {
        char buf[8]; // resulting string limited to 7 chars
        va_list args;
        va_start (args, fmt );
        vsnprintf(buf, 8, fmt, args);
        va_end (args);
        _LoRaSerial.print(buf);
}