Heltec LoRa

TBD

Heltec LoRa

Lora permite conectar los dispositivos en varias topologías: punto a punto y en estrella (un nodo hace de gateway).

Además, tiene mayor alcance que WiFi o Bluetooth, por lo que algunos fabricantes incorporan alguna de estas otras redes para dar cobertura a otros sensores que no tienen LoRa.

Así, podríamos tener capacidad de leer sensores a más distancia que la que permiten los protocolos WiFi o Bluetooth, [como se ve en este link.](https://randomnerdtutorials.com/esp32-lora-rfm95-transceiver-arduino-ide/)

Para usar LoRa en Arduino IDE es necesario installar la librería correspondiente:

Algunos proyectos:

• GPS -LoRa- Tracker
• Temperature -LoRa- Tracker

Lora DHT11 Sender

#include <SPI.h>
#include <LoRa.h>
#include "SSD1306.h"
#include<Arduino.h>
#include <U8x8lib.h>

#include "DHT.h"

#define DHTTYPE DHT11

const int DHTPin = 23;

DHT dht(DHTPin, DHTTYPE);

 
//OLED pins to ESP32 GPIOs via this connecthin:
//OLED_SDA -- GPIO4
//OLED_SCL -- GPIO15
//OLED_RST -- GPIO16
 
SSD1306  display(0x3c, 4, 15);
 
// 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    868E6 //433E6  //915E6 

U8X8_SSD1306_128X64_NONAME_SW_I2C u8x8(/* clock=*/ 15, /* data=*/ 4, /* reset=*/ 16);

int counter = 0;
 
void setup() {
  pinMode(DHTPin, INPUT);
  dht.begin();
  
  pinMode(25,OUTPUT); //Send success, LED will bright 1 second
  pinMode(16,OUTPUT);
  digitalWrite(16, LOW);    // set GPIO16 low to reset OLED
  delay(50); 
  digitalWrite(16, HIGH);
   
  Serial.begin(115200);
  while (!Serial); //If just the the basic function, must connect to a computer
  // Initialising the UI will init the display too.
  //display.init();
  //display.flipScreenVertically();
  //display.setFont(ArialMT_Plain_10);
  //display.setTextAlignment(TEXT_ALIGN_LEFT);
  //display.drawString(5,5,"LoRa Sender");
  //display.display();
  u8x8.begin();
  u8x8.setFont(u8x8_font_chroma48medium8_r);
  u8x8.drawString(0, 1, "LoRa Sender");
   
  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!");
  //display.drawString(5,20,"LoRa Initializing OK!");
  u8x8.drawString(0, 1, "LoRa Initializing OK!");
  //display.display();
  delay(2000);
}
void loop() {
  Serial.print("Sending packet: ");
  Serial.println(counter);
  //display.clear();
  //display.setFont(ArialMT_Plain_16);
  //display.drawString(3, 5, "Sending packet ");
  //display.drawString(50, 30, String(counter));
  //display.display();
  u8x8.drawString(3, 5, "Sending packet ");
  u8x8.setCursor(0, 6);
  u8x8.print(counter); 
  u8x8.display();

  float h = dht.readHumidity();
  float t = dht.readTemperature();
  Serial.println(t);
  u8x8.setCursor(0, 7);
  u8x8.print(t); 
  u8x8.display();
  // send packet
  LoRa.beginPacket();
  LoRa.print("Temp: ");
  LoRa.print(t);
  LoRa.print(" // MSG: ");
  LoRa.print(counter);
  LoRa.endPacket();
  counter++;
  digitalWrite(25, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(1000);                       // wait for a second
  digitalWrite(25, LOW);    // turn the LED off by making the voltage LOW
  delay(1000);                       // wait for a second
  //delay(1000);
}

Lora Receiver

#include <U8x8lib.h>
#include <LoRa.h>

String receivedText;
String receivedRssi;

// 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    433E6

// the OLED used
U8X8_SSD1306_128X64_NONAME_SW_I2C u8x8(/* clock=*/ 15, /* data=*/ 4, /* reset=*/ 16);

void setup() {

  SPI.begin(5, 19, 27, 18);
  LoRa.setPins(SS, RST, DI0);

  Serial.begin(115200);
  while (!Serial); //if just the the basic function, must connect to a computer
  delay(1000);

  u8x8.begin();
  u8x8.setFont(u8x8_font_chroma48medium8_r);

  Serial.println("LoRa Receiver");
  u8x8.drawString(0, 1, "LoRa Receiver");

  if (!LoRa.begin(BAND)) {
    Serial.println("Starting LoRa failed!");
    u8x8.drawString(0, 1, "Starting LoRa failed!");
    while (1);
  }
}

void loop() {

  // try to parse packet
  int packetSize = LoRa.parsePacket();
  if (packetSize) {
    // received a packet
    Serial.print("Received packet '");
    u8x8.drawString(0, 4, "PacketID");

    // read packet
    while (LoRa.available()) {
      receivedText = (char)LoRa.read();
      Serial.print(receivedText);
      char currentid[64];
      receivedText.toCharArray(currentid, 64);
      u8x8.drawString(9, 4, currentid);
    }

    // print RSSI of packet
    Serial.print("' with RSSI ");
    Serial.println(LoRa.packetRssi());
    u8x8.drawString(0, 5, "PacketRS");
    receivedRssi = LoRa.packetRssi();
    char currentrs[64];
    receivedRssi.toCharArray(currentrs, 64);
    u8x8.drawString(9, 5, currentrs);
  }

}

Más información en este link.