// This example just provide basic LoRa function test;
// Not the LoRa's farthest distance or strongest interference immunity.
// For more informations, please vist www.heltec.cn or mail to support@heltec.cn

#include <SPI.h>
#include <LoRa.h>
#include<Arduino.h>
#include "SSD1306.h "
// WIFI_LoRa_32 ports

// GPIO5  -- SX1278's SCK
// GPIO19 -- SX1278's MISO
// GPIO27 -- SX1278's MOSI
// GPIO18 -- SX1278's CS
// GPIO14 -- SX1278's RESET
// GPIO26 -- SX1278's IRQ(Interrupt Request)

#define SS      18
#define RST     14
#define DI0     26
#define BAND    833E6  //915E6 -- 这里的模式选择中，检查一下是否可在中国实用915这个频段

int counter = 0;

SSD1306  display(0x3c, 4, 15);


void setup() {
  pinMode(25,OUTPUT); //Send success, LED will bright 1 second

  Serial.begin(115200);
  while (!Serial); //If just the the basic function, must connect to a computer

  SPI.begin(5,19,27,18);
  LoRa.setPins(SS,RST,DI0);
//  Serial.println("LoRa Sender");

  if (!LoRa.begin(BAND)) {
    Serial.println("Starting LoRa failed!");
    while (1);
  }
  Serial.println("LoRa Initial OK!");

  pinMode(16,OUTPUT);
  digitalWrite(16, LOW);    // set GPIO16 low to reset OLED
  delay(50);
  digitalWrite(16, HIGH); // while OLED is running, must set GPIO16 in high

  display.init();
  display.setContrast(255);

  // register the receive callback
  //LoRa.onReceive(onReceive);

  // put the radio into receive mode
  //LoRa.receive();
}
void fillRect(void) {
  uint8_t color = 1;
  for (int16_t i=0; i<DISPLAY_HEIGHT/2; i+=3) {
    display.setColor((color % 2 == 0) ? BLACK : WHITE); // alternate colors
    display.fillRect(i, i, DISPLAY_WIDTH - i*2, DISPLAY_HEIGHT - i*2);
    display.display();
    delay(10);
    color++;
  }
  // Reset back to WHITE
  display.setColor(WHITE);
}
void loop() {
  int packetSize = LoRa.parsePacket();
  if (packetSize) {
    // received a packet
    Serial.print("Received packet '");
    display.clear();
    display.setColor(WHITE); // alternate colors
    display.drawString(0, 0, String(counter++,DEC));
    display.drawString(0, 20, String(LoRa.packetRssi(),DEC));
    display.display();
    // read packet
    while (LoRa.available()) {
      Serial.print((char)LoRa.read());
    }
    Serial.println("Send back");
    LoRa.beginPacket();
    LoRa.print("ACK ");
    LoRa.print(counter);
    LoRa.endPacket();

    // print RSSI of packet
    Serial.print("' with RSSI ");
    Serial.println(LoRa.packetRssi());
  }
}