UART issues please help

so, i am interfacing esp8266 wemos d1 mini with atmega328. ATmega328 sending data to esp8266 using serial communication. I think the serial is not working correctly.

when i powered up 2 board,the esp can connect to my local mqtt and sending "no_data", even though i see on my atmega328 lcd that the data was sent correctly.

but when i connect to wemos using espruino ide over ip address. i magically can send the data to mqtt correctly.

i've tries several times, that i need to connect to esp through espruino program on computer as if it is "openning the lock" on my uart port on esp.

where is the mistake?

Serial1.setup(19200,{rx:D3,tx:D1});

var mqtt = require("tinyMQTT").create(server, {
    username: "a",
    password: "asdfghjkl",
    port: 1883
});

function konekwifi()
{
  wifi.connect("qwer",{password:"asdfqwer"­},
  function(){
    mqtt.connect();
  });
}

function kirimdata()
{
  var bsplit=buff.split(",");
  if(buff!='' && bsplit.length>=3)
  {
    mqtt.publish("posisi/"+clientid, JSON.stringify(
      {
        'name':clientid,
        'lat':bsplit[0], 
        'lon':bsplit[1], 
        'pm':bsplit[2]
      }));
  } else
  {
    console.log(bsplit.length+'_no_data_'+bu­ff);
    mqtt.publish("status/"+clientid, "no_data_"+bsplit.length);
  }
}

function onInit() {
  konekwifi();
  wifi.stopAP();

  setTimeout(function(){
    if (wifi.getIP().ip!='0.0.0.0'){
      console.log(wifi.getIP());
    } else {konekwifi();}
  }, 15000);
}


//event handler
Serial1.on('data', 
function (data) { 
  buff=data;
});

setInterval(kirimdata, 2000);