/*
  This is a simple example show the Heltec.LoRa recived data in OLED.

  The onboard OLED display is SSD1306 driver and I2C interface. In order to make the
  OLED correctly operation, you should output a high-low-high(1-0-1) signal by soft-
  ware to OLED's reset pin, the low-level signal at least 5ms.

  OLED pins to ESP32 GPIOs via this connecthin:
  OLED_SDA -- GPIO4
  OLED_SCL -- GPIO15
  OLED_RST -- GPIO16
  
  by Aaron.Lee from HelTec AutoMation, ChengDu, China
  成都惠利特自动化科技有限公司
  www.heltec.cn
  
  this project also realess in GitHub:
  https://github.com/Heltec-Aaron-Lee/WiFi_Kit_series
*/
#include "heltec.h" 


#define BAND    868E6  //you can set band here directly,e.g. 868E6,915E6
String rssi = "RSSI --";
String packSize = "--";
String packet ;



void LoRaData(){
  Heltec.display->clear();
  Heltec.display->setTextAlignment(TEXT_ALIGN_LEFT);
  Heltec.display->setFont(ArialMT_Plain_10);
  Heltec.display->drawString(0 , 15 , "Received "+ packSize + " bytes");
  Heltec.display->drawStringMaxWidth(0 , 26 , 128, packet);
  Heltec.display->drawString(0, 0, rssi);  
  Heltec.display->display();
}

void cbk(int packetSize) {
  packet ="";
  packSize = String(packetSize,DEC);
  for (int i = 0; i < packetSize; i++) { packet += (char) LoRa.read(); }
  rssi = "RSSI " + String(LoRa.packetRssi(), DEC) ;
  LoRaData();
}

void setup() { 
   //WIFI Kit series V1 not support Vext control
  Heltec.begin(true /*DisplayEnable Enable*/, true /*Heltec.Heltec.Heltec.LoRa Disable*/, true /*Serial Enable*/, true /*PABOOST Enable*/, BAND /*long BAND*/);
  //
  LoRa.setSpreadingFactor(8);
    // put in standby mode
  LoRa.setSignalBandwidth(125E3);
  LoRa.setCodingRate4(4);
  LoRa.setSyncWord(0x12);   //0x34
  LoRa.setPreambleLength(8);
  
  Heltec.display->init();
  Heltec.display->flipScreenVertically();  
  Heltec.display->setFont(ArialMT_Plain_10);

  delay(1500);
  Heltec.display->clear();
  
  Heltec.display->drawString(0, 0, "Heltec.LoRa Initial success!");
  Heltec.display->drawString(0, 10, "Wait for incoming data...");
  Heltec.display->display();
  delay(1000);
  //LoRa.onReceive(cbk);
  LoRa.receive();
}

void loop() {
  int packetSize = LoRa.parsePacket();
  if (packetSize) { cbk(packetSize);  }
  delay(10);
}