mDot_sate_manger.js

// a very simple mDot LoRaWAN connection manager

var tx_wdog = {intv: 60000,  counter:0, flag: false,  sendingFlag: null, ts:null, tid:null};
var con = {state:0, statePrevious: 0, cmd: null, msg: null, status: null, rx_msg: null, sendInt: 60000};
var tx_string = '';
var rx_string = '';
var log = true;

function cLog(logMsg){
    var d = new Date(); 
    print(d.toUTCString()+ ' '+ logMsg);
}

function serialSend(tx_msg){
    d = new Date(); 
    tx_wdog.sendingFlag = true;
    Serial1.print(tx_msg+"\r\n"); 
}


// tx-downlink 
Serial1.on('data', function (data) { 

  var hexVal = String(data).charCodeAt(0);
  var _rx = "";
  
  for (as=0; as<data.length; as++){
    hexVal = String(data).charCodeAt(as);
    if(hexVal == 10 || hexVal == 13){ //  \r Carriage Return 0x0D, 13 -- \n Line Feed 0x0A, 10
      //_rx += <cr-lf>;
    } else {
       _rx += String.fromCharCode(hexVal);
    }
  }

  rx_string = rx_string + _rx;

  // con.cmd responce terminator OK or ERROR
  if(rx_string.indexOf("OK") >=0){
     tx_wdog.sendingFlag = false;
     tx_wdog.counter = 0;
     conLEDs(0);
     rx_string = rx_string.replace("OK","");
    
     if(con.state <4){
       cLog("rx: Ok - "+rx_string);
       stateMan(rx_string,'OK');
     } else {
       cLog("rx: Ok - "+rx_string);
       cmdHandler(rx_string);
     }
     rx_string = "";
    
  } else if (rx_string.indexOf("ERROR") >=0){
     tx_wdog.sendingFlag = false;
     tx_wdog.counter = 0;
     rx_string = rx_string.replace("ERROR","");
     cLog("rx: Error - "+rx_string);
     stateMan(rx_string,'ERROR');
     rx_string = "";
  }

});

function cmdHandler(rx){
	// handle downlink commmands
}

// LoRaWAN connection manager
function stateMan(response,rType){
// *************************
// State transition manager
// *************************
  //cLog('res: '+response+' type: '+ rType+' cmd: '+con.cmd+' state: '+con.state);

  if(con.state === 4 && rType === 'OK'){
    return;
  }

  // t5 & t6 handle errors on joined network
  if(con.state === 4 && rType === 'ERROR'){
    con.cmd = null;
    //cLog('network not joined: '+response.indexOf("network not joined"));
    if(response.indexOf("network not joined")>0){  // transtion to s2 re-join network 
      con.state = 2;
    }
    if(response.indexOf("Operation Timed Out")>0){   
      //con.state = 2;
    }
   
  }

  //s0 Test for mDot
  if(con.state === 0){
    if(con.cmd === null ){
      cLog('re/starting state mananger');
      con.cmd = "AT";
      serialSend(con.cmd);

    } else if (rType === 'OK'){    // t1
      con.cmd = null;
      con.statePrevious = 0;
      con.state = 1;

    } else if (con.cmd === "AT" && rType === 'ERROR'){
      con.cmd = null;
      setTimeout(function() {
         stateMan('','');
      },30000);
    }
  }

  //s1 echo off
  if(con.state === 1){

    if(con.cmd === null){
      con.cmd = "ATE0";
      serialSend(con.cmd);

    } else if (con.cmd === "ATE0" && rType === 'OK'){  // t2
      con.cmd = null;
      con.statePrevious = 1;
      con.state = 2;
    }
  }

  // s2 join network  
  if(con.state === 2){

    if(con.cmd === null){
      con.cmd = "AT+JOIN";
      serialSend(con.cmd);

   } else if (con.cmd === "AT+JOIN" && rType === 'OK'){ // t3 joined ok
      con.cmd = null;
      con.statePrevious = 1;
      con.state = 3;

   } else if (rType === 'ERROR'){  // t4 join failed
      con.cmd = null;
      setTimeout(function(){stateMan('','');},60000);
    }
  }

  // s3 Joined network so recive msg from Conduit in hex
  if(con.state === 3){
     if(con.cmd === null){
       con.cmd = "AT+RXO=1";
       serialSend(con.cmd);
       con.cmd = null;
       con.statePrevious = 3;
       con.state = 4;
     }
  }
}

// watch dog
function tx_watchDog(){

  //cLog('tx watch dog count: '+tx_wdog_counter);

  if(tx_wdog.flag){
    con.cmd = null;  // Re-Start state manager
    con.state = 0;
    tx_wdog.flag = false;
    stateMan('','');
  }

  if(tx_wdog.sendingFlag){ 
    tx_wdog.counter++;
    if(tx_wdog.counter > 2){
      cLog('tx watch dog expired re-set mDot');
      var d = new Date(); 
      tx_wdog.ts = d.toUTCString();
      tx_wdog.sendingFlag = false;
      tx_wdog.counter = 0;
      tx_wdog.flag = true;
      digitalWrite(B1,0); // hard re-set mDot
    }
  }
}
setInterval(tx_watchDog,tx_wdog.intv);  // tick every x sec

// called once on boot 
function onInit(){
  cLog('on init');
  stateMan('','');
}