ESP32 Lora Home Automation, Long Rage Lora Sender and Receiver, LoRa SX1278

LoRa ESP32 Home Automation Project

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Table of Contents

ESP32 LoRa Home Automation:

ESP32 Lora Home Automation, Long Rage Lora Sender and Receiver- So far I have used LoRa Transceiver modules with Arduino, Nodemcu ESP8266, and STM32 controller boards. Today, for the first time I am going to use these Long Range LoRa SX1278 Transceiver modules with ESP32 controller boards.

As you know ESP32 is much more powerful than the ESP8266 and Arduino. It is even faster than the Raspberry Pi Pico and STM32. And as you might know, ESP32 has onboard WiFi and Bluetooth and this is what makes the ESP32 much more popular than all the other controller boards.

So, in today’s article, you will learn how to make a Long range of wireless Home automation systems using ESP32 WiFi + Bluetooth modules, LoRa SX1278 Transceiver modules, 12V SPDT type relays, 110/220Vac Bulbs, and some switches.

In this project, I am using two ESP32 modules, one as the sender and the other one as the receiver.

You might have noticed, that I am using two different versions of the ESP32 WiFi + Bluetooth modules. I could use the similar ESP32 modules, but the reason I am using different versions is that to explain it doesn’t matter which one of these you use; the code is going to work just fine.

You can see 4 buttons on the transmitter side. Using these 4 buttons, I am going to control certain loads on the receiver side. For demonstration purposes, I have put 4 bulbs on the receiver’s side, which are connected to 4 relays. Besides lights, you can use any other 110/220Vac loads or use any other DC type loads.

If you want to use 110/220Vac supply, you must not forget to use protective gloves, because 110/220Vac can prove fatal. So, as far as possible you must ensure the presence of a friend or any companion while working on such projects. When the AC supply is ON, do not touch the relay contacts. Now, let’s go ahead and kick off our practical demonstration.

Practical Demonstration:

I have connected everything as per the circuit diagrams which I will explain in a minute.

Now you can see, that I have turned ON the receiver side using a 12V adaptor. And I have also connected the 220Vac. Let me remind you once again. When the 220Vac supply is connected never touch the relay contacts.

You can also use a solar panel or 12V battery to power up the ESP32 controller board as I am using 7805 Voltage regulator.

I am powering up the transmitter side through a 4S Lithium Ion Battery Pack. You may also use a 3S lipo battery pack or any other type of battery or a DC adopter for this purpose. If you also want to make such a 4S Lithium Ion battery pack, then I highly recommend read my article on 4S lithium Ion Battery Pack.

You can make the transmitter side much smaller by designing your own PCB. And you can use small toggle switches to control the AC or DC loads.

I can randomly turn ON or turn OFF any light and it is working quite superbly.

I am sure by now, you might have got an idea of how does this system work. So, without any further delay let’s get started!!!

Amazon Links:

LoRa SX1278 Module

12v Adaptor

ESP32 WiFi + Bluetooth Module(Recommended)

LM7805 Voltage Regulator

12V SPDT Relay

*Disclosure: These are affiliate links. As an Amazon Associate I earn from qualifying purchases.

SX1278 LoRa Module:

In this project, we are using the same SX-1278 LoRa modules for the transmitter and receiver. In order to use it as a receiver and transmitter, we will make changes in the code. Lora SX-1278 long-distance wireless transceiver module integrates Semtech RF transceiver chip SX1278, which adopts LoRa TM Spread Spectrum modulation frequency hopping technique. The features of long distance and high sensitivity (-139dBm) make this module perform better than FSK and GFSK modules. Multi-signal won’t affect each other even in a crowd frequency environment; it comes with strong anti-interference performance. This module is 100mW and ultra-small size, widely used in AMR, remote industrial control field.

Features:

Frequency Range: 868 / 915 MHz
Sensitivity up to -139dBm @Lora
Maximum output power: 20 dBm
13mA@receiver mode
Sleep current <200 nA
Data transfer rate: @FSK,1.2-300 Kbps
@Lora TM, 0.018-37.5 Kbps
Lora TM, FSK, GFSK & OOK Modulation mode
Built-in ESD Protection
127 dB Dynamic Range RSSI
Packet engine up to 256 bytes with FIFO and CRC
Hopping frequency
Built-in temperature sensor and low battery indicator
Excellent blocking immunity
Operating Temperature Range：-40 ~ + 85 °C

Applications:

Remote control
Remote meter reading
Home security alarm and remote keyless entry
Industrial control
Home automation remote sensing
Individual data records
Toys control
Sensor network
Tire pressure monitoring
Health monitoring
Wireless PC peripherals
Tag reading and writing

ESP32 LoRa Home Automation Circuit Diagrams:

ESP32 LoRa Transmitter Circuit Diagram:

This is the transmitter side circuit diagram. I am using 5V regulated power supply based on the LM7805 linear voltage regulator. The output of the regulator is connected with the Vin pin on the ESP32 module.

The NSS pin of the LoRa module is connected with the GPIO5, the MOSI pin is connected with the GPIO23, the MISO is connected with the GPIO19, and the SCK pin of the SX1278 LoRa module is connected with the GPIO18. Make sure the ground of the ESP32 module is connected with the ground pin of the LoRa transceiver module.

On the left side you can see, 4 switches are connected with the GIPO pins 33, 26, 14, and 13. Now, let’s take a look at the receiver side circuit diagram.

ESP32 LoRa Receiver Circuit Diagram:

The connections of the 5V regulated power supply and SX1278 LoRa transceiver module remain exactly the same.

4 SPDT type relays are connected with the GPIO pins 27, 14, 12, and 13. You can connect AC or DC loads with the Relays Common and Normally Open contacts. You can also see freewheeling diodes are connected across the relays coil pins. You can use 1N4007 diodes. I am using a pair of 10K ohm and 2N2222 NPN transistor to control each relay. So, using these connections you can make your own 4-channel relay module or you can use a readymade 4-channel relay module. Read my article on how to control different types of relays.

ESP32 Home Automation Project PCBs:

Download Gerber files:

These are the PCB boards which I received from the JLCPCB as you can see the quality is really great. The silkscreen is quite clear and the Black Solder mask looks amazing. Next, I started off by placing the components and completed the soldering job.

Libraries Needed:

Before, you start the programming, first of all, make sure you download the LoRa library.

Download: LoRa.h

Download: Adafruit_GFX.h

Download: Adafruit_SSD1306.h

You will need the LoRa library for the LoRa transceiver modules.The Adafruit_GFX and Adafruit_SSD1306 libraries are used with the Oled display module. So, if you want to display the feedback message on the Oled display then you will need these two libraries. I have added code for the feedback message.

If you are using the ESP32 WiFi + Bluetooth module for the first then you will need to know about the pinout and how to install the ESP32 board manager url link. So, I highly recommend, you guys should read my getting started tutorial on the ESP32.

ESP32 LoRa Programming:

ESP32 LoRa Tx Side Code:

<span style="font-family: georgia, palatino, serif;">/*
  Transmitter code
  
  ESP32 LoRa Home Automation Project by
  https://www.electroniclinic.com/
*/
#include <SPI.h>              // include libraries
#include <LoRa.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#define nss 5
#define rst 34
#define dio0 2


int sw1 = 33; 
int sw2 = 13; 
int sw3 = 14; 
int sw4 = 26;
int Sensor1 = 0; 
int Sensor2 = 0; 
int Sensor3 = 0;  
int Sensor4 = 0;  
boolean bflag = false;
String outgoing;              // outgoing message

byte msgCount = 0;            // count of outgoing messages
byte localAddress = 0xBB;     // address of this device
byte destination = 0xFF;      // destination to send to
long lastSendTime = 0;        // last send time
int interval = 50;          // interval between sends

// For Oled display
#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels
// Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
#define OLED_RESET     -1 // Reset pin # (or -1 if sharing Arduino reset pin)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);
 
String Mymessage = "";
void setup() {
  Serial.begin(9600);                   // initialize serial
   LoRa.setPins(nss, rst, dio0);
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
  display.clearDisplay();
  display.setTextColor(WHITE);

 
    pinMode(sw1, INPUT_PULLUP);
  pinMode(sw2, INPUT_PULLUP); 
  pinMode(sw3, INPUT_PULLUP); 
 pinMode(sw4, INPUT_PULLUP);

  Serial.println("LoRa Duplex");

  if (!LoRa.begin(433E6)) {             // initialize ratio at 915 MHz
    Serial.println("LoRa init failed. Check your connections.");
    while (true);                       // if failed, do nothing
  }

  Serial.println("LoRa init succeeded.");
}

void loop() {
  
  if (millis() - lastSendTime > interval) {
   Sensor1 = digitalRead(sw1);
    delay(10);
    Sensor2 = digitalRead(sw2); 
    delay(10);
    Sensor3 = digitalRead(sw3);
    delay(10);
       Sensor4 = digitalRead(sw4);
    delay(10);
    Mymessage = Mymessage + Sensor1 +"," + Sensor2 + "," + Sensor3 +"," + Sensor4;  
    sendMessage(Mymessage);
    delay(100);
    Mymessage = "";
    
    //Serial.println("Sending " + message);
    lastSendTime = millis();            // timestamp the message
    interval = random(50) + 100;  
    
    }

      // parse for a packet, and call onReceive with the result:
  onReceive(LoRa.parsePacket());
  }





void sendMessage(String outgoing) {
  LoRa.beginPacket();                   // start packet
  LoRa.write(destination);              // add destination address
  LoRa.write(localAddress);             // add sender address
  LoRa.write(msgCount);                 // add message ID
  LoRa.write(outgoing.length());        // add payload length
  LoRa.print(outgoing);                 // add payload
  LoRa.endPacket();                     // finish packet and send it
  msgCount++;                           // increment message ID
}

void onReceive(int packetSize) {
  if (packetSize == 0) return;          // if there's no packet, return

  // read packet header bytes:
  int recipient = LoRa.read();          // recipient address
  byte sender = LoRa.read();            // sender address
  byte incomingMsgId = LoRa.read();     // incoming msg ID
  byte incomingLength = LoRa.read();    // incoming msg length

  String incoming = "";

  while (LoRa.available()) {
    incoming += (char)LoRa.read();
  }

  if (incomingLength != incoming.length()) {   // check length for error
    //Serial.println("error: message length does not match length");
    ;
    return;                             // skip rest of function
  }

  // if the recipient isn't this device or broadcast,
  if (recipient != localAddress && recipient != 0xFF) {
   // Serial.println("This message is not for me.");
    ;
    return;                             // skip rest of function
  }

  // if message is for this device, or broadcast, print details:
  //Serial.println("Received from: 0x" + String(sender, HEX));
  //Serial.println("Sent to: 0x" + String(recipient, HEX));
  //Serial.println("Message ID: " + String(incomingMsgId));
 // Serial.println("Message length: " + String(incomingLength));
  Serial.println("Message: " + incoming);
//  Serial.println("RSSI: " + String(LoRa.packetRssi()));
//  Serial.println("Snr: " + String(LoRa.packetSnr()));
//  Serial.println();

    //clear display
  display.clearDisplay();

  display.setTextSize(2);
  display.setCursor(0,0);
  display.print("Status:");

  display.setTextSize(3);
  display.setCursor(0, 28);
  display.print(incoming);

display.display(); 
}
</span>

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<span style="font-family: georgia, palatino, serif;">/*

Transmitter code

ESP32 LoRa Home Automation Project by

https://www.electroniclinic.com/

#include <SPI.h> // include libraries

#include <LoRa.h>

#include <Adafruit_GFX.h>

#include <Adafruit_SSD1306.h>

#define nss 5

#define rst 34

#define dio0 2

int sw1 = 33;

int sw2 = 13;

int sw3 = 14;

int sw4 = 26;

int Sensor1 = 0;

int Sensor2 = 0;

int Sensor3 = 0;

int Sensor4 = 0;

boolean bflag = false;

String outgoing; // outgoing message

byte msgCount = 0; // count of outgoing messages

byte localAddress = 0xBB; // address of this device

byte destination = 0xFF; // destination to send to

long lastSendTime = 0; // last send time

int interval = 50; // interval between sends

// For Oled display

#define SCREEN_WIDTH 128 // OLED display width, in pixels

#define SCREEN_HEIGHT 64 // OLED display height, in pixels

// Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)

#define OLED_RESET -1 // Reset pin # (or -1 if sharing Arduino reset pin)

Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

String Mymessage = "";

void setup() {

Serial.begin(9600); // initialize serial

LoRa.setPins(nss, rst, dio0);

display.begin(SSD1306_SWITCHCAPVCC, 0x3C);

display.clearDisplay();

display.setTextColor(WHITE);

pinMode(sw1, INPUT_PULLUP);

pinMode(sw2, INPUT_PULLUP);

pinMode(sw3, INPUT_PULLUP);

pinMode(sw4, INPUT_PULLUP);

Serial.println("LoRa Duplex");

if (!LoRa.begin(433E6)) { // initialize ratio at 915 MHz

Serial.println("LoRa init failed. Check your connections.");

while (true); // if failed, do nothing

}

Serial.println("LoRa init succeeded.");

}

void loop() {

if (millis() - lastSendTime > interval) {

Sensor1 = digitalRead(sw1);

delay(10);

Sensor2 = digitalRead(sw2);

delay(10);

Sensor3 = digitalRead(sw3);

delay(10);

Sensor4 = digitalRead(sw4);

delay(10);

Mymessage = Mymessage + Sensor1 +"," + Sensor2 + "," + Sensor3 +"," + Sensor4;

sendMessage(Mymessage);

delay(100);

Mymessage = "";

//Serial.println("Sending " + message);

lastSendTime = millis(); // timestamp the message

interval = random(50) + 100;

}

// parse for a packet, and call onReceive with the result:

onReceive(LoRa.parsePacket());

}

void sendMessage(String outgoing) {

LoRa.beginPacket(); // start packet

LoRa.write(destination); // add destination address

LoRa.write(localAddress); // add sender address

LoRa.write(msgCount); // add message ID

LoRa.write(outgoing.length()); // add payload length

LoRa.print(outgoing); // add payload

LoRa.endPacket(); // finish packet and send it

msgCount++; // increment message ID

}

void onReceive(int packetSize) {

if (packetSize == 0) return; // if there's no packet, return

// read packet header bytes:

int recipient = LoRa.read(); // recipient address

byte sender = LoRa.read(); // sender address

byte incomingMsgId = LoRa.read(); // incoming msg ID

byte incomingLength = LoRa.read(); // incoming msg length

String incoming = "";

while (LoRa.available()) {

incoming += (char)LoRa.read();

}

if (incomingLength != incoming.length()) { // check length for error

//Serial.println("error: message length does not match length");

;

return; // skip rest of function

}

// if the recipient isn't this device or broadcast,

if (recipient != localAddress && recipient != 0xFF) {

// Serial.println("This message is not for me.");

;

return; // skip rest of function

}

// if message is for this device, or broadcast, print details:

//Serial.println("Received from: 0x" + String(sender, HEX));

//Serial.println("Sent to: 0x" + String(recipient, HEX));

//Serial.println("Message ID: " + String(incomingMsgId));

// Serial.println("Message length: " + String(incomingLength));

Serial.println("Message: " + incoming);

// Serial.println("RSSI: " + String(LoRa.packetRssi()));

// Serial.println("Snr: " + String(LoRa.packetSnr()));

// Serial.println();

//clear display

display.clearDisplay();

display.setTextSize(2);

display.setCursor(0,0);

display.print("Status:");

display.setTextSize(3);

display.setCursor(0, 28);

display.print(incoming);

display.display();

}

</span>

ESP32 LoRa Rx Side Code:

<span style="font-family: georgia, palatino, serif;">/*
 Receiver code
 
 ESP32 LoRa Home Automation Project by
 https://www.electroniclinic.com/
*/
#include <SPI.h>              // include libraries
#include <LoRa.h>

#define nss 5
#define rst 34
#define dio0 2

boolean flag1 = false;
boolean flag2 = false;

boolean flag3 = false;
boolean flag4 = false; 

int RLY1=12;
int RLY2=13;
int RLY3=14;
int RLY4=27;

int Sensor1 = 0; 
int Sensor2 = 0; 
int Sensor3 = 0; 
int Sensor4 = 0; 

int relay1Status;
int relay2Status;
int relay3Status;
int relay4Status;

String outgoing;              // outgoing message

byte msgCount = 0;            // count of outgoing messages
byte localAddress = 0xFF;     // address of this device
byte destination = 0xBB;      // destination to send to
long lastSendTime = 0;        // last send time
int interval = 50;          // interval between sends

String statusmessage = "";

void setup() {
  Serial.begin(9600);                   // initialize serial


 pinMode(RLY1,OUTPUT);
  pinMode(RLY2,OUTPUT);
    pinMode(RLY3,OUTPUT);
      pinMode(RLY4,OUTPUT);
 LoRa.setPins(nss, rst, dio0);
  Serial.println("LoRa Duplex");

  if (!LoRa.begin(433E6)) {             // initialize ratio at 915 MHz
    Serial.println("LoRa init failed. Check your connections.");
    while (true);                       // if failed, do nothing
  }

  Serial.println("LoRa init succeeded.");
}

void loop() {

  if (millis() - lastSendTime > interval) {
  relay1Status = digitalRead(RLY1);
       relay2Status = digitalRead(RLY2);
        relay3Status = digitalRead(RLY3);
         relay4Status = digitalRead(RLY4);
        statusmessage = statusmessage + relay1Status + "," + relay2Status + "," + relay3Status + "," + relay4Status;
        sendMessage(statusmessage); 
delay(10);
statusmessage = "";
    lastSendTime = millis();            // timestamp the message
    interval = random(50) + 100;  
  }
  

  // parse for a packet, and call onReceive with the result:
  onReceive(LoRa.parsePacket());
}

void sendMessage(String outgoing) {
  LoRa.beginPacket();                   // start packet
  LoRa.write(destination);              // add destination address
  LoRa.write(localAddress);             // add sender address
  LoRa.write(msgCount);                 // add message ID
  LoRa.write(outgoing.length());        // add payload length
  LoRa.print(outgoing);                 // add payload
  LoRa.endPacket();                     // finish packet and send it
  msgCount++;                           // increment message ID
}

void onReceive(int packetSize) {
  if (packetSize == 0) return;          // if there's no packet, return

  // read packet header bytes:
  int recipient = LoRa.read();          // recipient address
  byte sender = LoRa.read();            // sender address
  byte incomingMsgId = LoRa.read();     // incoming msg ID
  byte incomingLength = LoRa.read();    // incoming msg length

  String incoming = "";

  while (LoRa.available()) {
    incoming += (char)LoRa.read();
  }

  if (incomingLength != incoming.length()) {   // check length for error
   // Serial.println("error: message length does not match length");
   ;
    return;                             // skip rest of function
  }

  // if the recipient isn't this device or broadcast,
  if (recipient != localAddress && recipient != 0xFF) {
    //Serial.println("This message is not for me.");
    ;
    return;                             // skip rest of function
  }

  // if message is for this device, or broadcast, print details:
 // Serial.println("Received from: 0x" + String(sender, HEX));
 // Serial.println("Sent to: 0x" + String(recipient, HEX));
  //Serial.println("Message ID: " + String(incomingMsgId));
 // Serial.println("Message length: " + String(incomingLength));
  Serial.println("Message: " + incoming);
  //Serial.println("RSSI: " + String(LoRa.packetRssi()));
  //Serial.println("Snr: " + String(LoRa.packetSnr()));
  Serial.println();
   String q = getValue(incoming, ',', 0); 
String r = getValue(incoming, ',', 1); 
String s = getValue(incoming, ',', 2); 
String t = getValue(incoming, ',', 3); 
Sensor1 = q.toInt();
Sensor2 = r.toInt();
Sensor3 = s.toInt();
Sensor4 = t.toInt();
if((Sensor1 == 0)&&(flag1==true))
{
 
  digitalWrite(RLY1,HIGH);
   relay1Status = 1;
  Serial.println("Relay 1 is turned on");
  flag1=false;
}

if((Sensor1 == 1)&&(flag1 ==false))
{

  digitalWrite(RLY1,LOW);
   relay1Status = 0;
  Serial.println("Relay 1 is turned off");
  flag1=true;
}
if((Sensor2 == 0)&&(flag2==true))
{
 
  digitalWrite(RLY2,HIGH);
   relay2Status = 0;
  Serial.println("Relay 2 is turned on");
  flag2=false;
}

if((Sensor2 == 1)&&(flag2 ==false))
{

  digitalWrite(RLY2,LOW);
  relay2Status = 0;
  Serial.println("Relay 2 is turned off");
  flag2=true;
}
if((Sensor3 == 0)&&(flag3==true))
{
 
  digitalWrite(RLY3,HIGH);
  relay3Status = 1;
  Serial.println("Relay 3 is turned on");
  flag3=false;
}

if((Sensor3 == 1)&&(flag3 ==false))
{

  digitalWrite(RLY3,LOW);
  relay3Status = 0;
  Serial.println("Relay 3 is turned off");
  flag3=true;
}

if((Sensor4 == 0)&&(flag4==true))
{
 
  digitalWrite(RLY4,HIGH);
  relay4Status = 1;
  Serial.println("Relay 4 is turned on");
  flag4=false;
}

if((Sensor4 == 1)&&(flag4 ==false))
{

  digitalWrite(RLY4,LOW);
  relay4Status = 0;
  Serial.println("Relay 4 is turned off");
  flag4=true;
}

incoming = "";
  
}
String getValue(String data, char separator, int index)
{
    int found = 0;
    int strIndex[] = { 0, -1 };
    int maxIndex = data.length() - 1;
 
    for (int i = 0; i <= maxIndex && found <= index; i++) {
        if (data.charAt(i) == separator || i == maxIndex) {
            found++;
            strIndex[0] = strIndex[1] + 1;
            strIndex[1] = (i == maxIndex) ? i+1 : i;
        }
    }
    return found > index ? data.substring(strIndex[0], strIndex[1]) : "";
}
</span>

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<span style="font-family: georgia, palatino, serif;">/*

Receiver code

ESP32 LoRa Home Automation Project by

https://www.electroniclinic.com/

#include <SPI.h> // include libraries

#include <LoRa.h>

#define nss 5

#define rst 34

#define dio0 2

boolean flag1 = false;

boolean flag2 = false;

boolean flag3 = false;

boolean flag4 = false;

int RLY1=12;

int RLY2=13;

int RLY3=14;

int RLY4=27;

int Sensor1 = 0;

int Sensor2 = 0;

int Sensor3 = 0;

int Sensor4 = 0;

int relay1Status;

int relay2Status;

int relay3Status;

int relay4Status;

String outgoing; // outgoing message

byte msgCount = 0; // count of outgoing messages

byte localAddress = 0xFF; // address of this device

byte destination = 0xBB; // destination to send to

long lastSendTime = 0; // last send time

int interval = 50; // interval between sends

String statusmessage = "";

void setup() {

Serial.begin(9600); // initialize serial

pinMode(RLY1,OUTPUT);

pinMode(RLY2,OUTPUT);

pinMode(RLY3,OUTPUT);

pinMode(RLY4,OUTPUT);

LoRa.setPins(nss, rst, dio0);

Serial.println("LoRa Duplex");

if (!LoRa.begin(433E6)) { // initialize ratio at 915 MHz

Serial.println("LoRa init failed. Check your connections.");

while (true); // if failed, do nothing

}

Serial.println("LoRa init succeeded.");

}

void loop() {

if (millis() - lastSendTime > interval) {

relay1Status = digitalRead(RLY1);

relay2Status = digitalRead(RLY2);

relay3Status = digitalRead(RLY3);

relay4Status = digitalRead(RLY4);

statusmessage = statusmessage + relay1Status + "," + relay2Status + "," + relay3Status + "," + relay4Status;

sendMessage(statusmessage);

delay(10);

statusmessage = "";

lastSendTime = millis(); // timestamp the message

interval = random(50) + 100;

}

// parse for a packet, and call onReceive with the result:

onReceive(LoRa.parsePacket());

}

void sendMessage(String outgoing) {

LoRa.beginPacket(); // start packet

LoRa.write(destination); // add destination address

LoRa.write(localAddress); // add sender address

LoRa.write(msgCount); // add message ID

LoRa.write(outgoing.length()); // add payload length

LoRa.print(outgoing); // add payload

LoRa.endPacket(); // finish packet and send it

msgCount++; // increment message ID

}

void onReceive(int packetSize) {

if (packetSize == 0) return; // if there's no packet, return

// read packet header bytes:

int recipient = LoRa.read(); // recipient address

byte sender = LoRa.read(); // sender address

byte incomingMsgId = LoRa.read(); // incoming msg ID

byte incomingLength = LoRa.read(); // incoming msg length

String incoming = "";

while (LoRa.available()) {

incoming += (char)LoRa.read();

}

if (incomingLength != incoming.length()) { // check length for error

// Serial.println("error: message length does not match length");

;

return; // skip rest of function

}

// if the recipient isn't this device or broadcast,

if (recipient != localAddress && recipient != 0xFF) {

//Serial.println("This message is not for me.");

;

return; // skip rest of function

}

// if message is for this device, or broadcast, print details:

// Serial.println("Received from: 0x" + String(sender, HEX));

// Serial.println("Sent to: 0x" + String(recipient, HEX));

//Serial.println("Message ID: " + String(incomingMsgId));

// Serial.println("Message length: " + String(incomingLength));

Serial.println("Message: " + incoming);

//Serial.println("RSSI: " + String(LoRa.packetRssi()));

//Serial.println("Snr: " + String(LoRa.packetSnr()));

Serial.println();

String q = getValue(incoming, ',', 0);

String r = getValue(incoming, ',', 1);

String s = getValue(incoming, ',', 2);

String t = getValue(incoming, ',', 3);

Sensor1 = q.toInt();

Sensor2 = r.toInt();

Sensor3 = s.toInt();

Sensor4 = t.toInt();

if((Sensor1 == 0)&&(flag1==true))

{

digitalWrite(RLY1,HIGH);

relay1Status = 1;

Serial.println("Relay 1 is turned on");

flag1=false;

}

if((Sensor1 == 1)&&(flag1 ==false))

{

digitalWrite(RLY1,LOW);

relay1Status = 0;

Serial.println("Relay 1 is turned off");

flag1=true;

}

if((Sensor2 == 0)&&(flag2==true))

{

digitalWrite(RLY2,HIGH);

relay2Status = 0;

Serial.println("Relay 2 is turned on");

flag2=false;

}

if((Sensor2 == 1)&&(flag2 ==false))

{

digitalWrite(RLY2,LOW);

relay2Status = 0;

Serial.println("Relay 2 is turned off");

flag2=true;

}

if((Sensor3 == 0)&&(flag3==true))

{

digitalWrite(RLY3,HIGH);

relay3Status = 1;

Serial.println("Relay 3 is turned on");

flag3=false;

}

if((Sensor3 == 1)&&(flag3 ==false))

{

digitalWrite(RLY3,LOW);

relay3Status = 0;

Serial.println("Relay 3 is turned off");

flag3=true;

}

if((Sensor4 == 0)&&(flag4==true))

{

digitalWrite(RLY4,HIGH);

relay4Status = 1;

Serial.println("Relay 4 is turned on");

flag4=false;

}

if((Sensor4 == 1)&&(flag4 ==false))

{

digitalWrite(RLY4,LOW);

relay4Status = 0;

Serial.println("Relay 4 is turned off");

flag4=true;

}

incoming = "";

}

String getValue(String data, char separator, int index)

{

int found = 0;

int strIndex[] = { 0, -1 };

int maxIndex = data.length() - 1;

for (int i = 0; i <= maxIndex && found <= index; i++) {

if (data.charAt(i) == separator || i == maxIndex) {

found++;

strIndex[0] = strIndex[1] + 1;

strIndex[1] = (i == maxIndex) ? i+1 : i;

}

return found > index ? data.substring(strIndex[0], strIndex[1]) : "";

}

</span>

Actually, these codes are from my previous project based on the Arduino. I have already explained the programming. I practically demonstrated the feedback message feature, this is an important feature, when you press a button on the transmitter side, the receiver side sends you a feedback message that the desired load is turned ON or turned OFF. I also practically checked the communication range of LoRa transceiver modules. So, I highly recommend you guys need to read my previous article on Lora Home automation using Arduino, if you want to learn the most important things. Anyway.

If you don’t want the feedback message feature, then simply don’t connect the Oled display module. The code is still going to work. As in my case I am not using an Oled display. So, that’s all about the programming.