LoRa Communication - Kinematrix

Kinematrix provides multiple LoRa implementations for long-range, low-power wireless communication supporting distances up to 10+ kilometers.

LoRa Modules Overview

LoRa Base

Foundation LoRa library (Sandeep Mistry)

LoRa Com V2

Enhanced communication with mesh and half-duplex modes

LoRa EByte E220

EByte E220 module-specific implementation

LoRa Specifications

Parameter	Value	Notes
Range	Up to 10-15 km	Line of sight, depends on environment
Frequency	433 MHz, 868 MHz, 915 MHz	Region-dependent
Data Rate	0.3 - 50 kbps	Configurable spreading factor
Power Consumption	10-120 mA TX, <1 mA sleep	Very low for IoT
Spreading Factor	SF7 - SF12	Higher SF = longer range, lower speed
Bandwidth	125 kHz, 250 kHz, 500 kHz	Configurable
TX Power	2-20 dBm	Typically 17-20 dBm

LoRa Base

Foundation LoRa library based on Sandeep Mistry’s implementation, providing core SPI-based LoRa functionality.

Hardware Configuration

lib/modules/communication/wireless/lora/lora-base.h

// Default pins (Arduino)
#define LORA_DEFAULT_SPI           SPI
#define LORA_DEFAULT_SPI_FREQUENCY 8E6
#define LORA_DEFAULT_SS_PIN        10  // Chip select
#define LORA_DEFAULT_RESET_PIN     9   // Reset
#define LORA_DEFAULT_DIO0_PIN      2   // Interrupt

Basic Transmitter

#define ENABLE_MODULE_LORA_BASE
#include "Kinematrix.h"

void setup() {
  Serial.begin(115200);
  
  // Initialize LoRa at 915 MHz
  if (!LoRa.begin(915E6)) {
    Serial.println("LoRa init failed!");
    while (1);
  }
  
  // Configure LoRa parameters
  LoRa.setTxPower(17);              // 17 dBm
  LoRa.setSpreadingFactor(8);       // SF8
  LoRa.setSignalBandwidth(125E3);   // 125 kHz
  LoRa.setCodingRate4(5);           // 4/5 coding rate
  LoRa.enableCrc();                 // Enable CRC
  
  Serial.println("LoRa initialized");
}

void loop() {
  Serial.println("Sending packet...");
  
  // Send packet
  LoRa.beginPacket();
  LoRa.print("Temperature: ");
  LoRa.print(25.5);
  LoRa.endPacket();
  
  delay(5000);
}

Basic Receiver

void setup() {
  Serial.begin(115200);
  
  if (!LoRa.begin(915E6)) {
    Serial.println("LoRa init failed!");
    while (1);
  }
  
  LoRa.setSpreadingFactor(8);
  LoRa.setSignalBandwidth(125E3);
  LoRa.enableCrc();
  
  Serial.println("LoRa receiver ready");
}

void loop() {
  int packetSize = LoRa.parsePacket();
  
  if (packetSize) {
    Serial.print("Received packet: ");
    
    // Read packet
    while (LoRa.available()) {
      Serial.write(LoRa.read());
    }
    
    // Print RSSI
    Serial.print(" RSSI: ");
    Serial.print(LoRa.packetRssi());
    Serial.print(" SNR: ");
    Serial.println(LoRa.packetSnr());
  }
}

Interrupt-Driven Reception

volatile bool packetReceived = false;

void onReceive(int packetSize) {
  packetReceived = true;
}

void setup() {
  Serial.begin(115200);
  LoRa.begin(915E6);
  
  // Register interrupt callback
  LoRa.onReceive(onReceive);
  
  // Put radio in receive mode
  LoRa.receive();
  
  Serial.println("LoRa receiver (interrupt mode)");
}

void loop() {
  if (packetReceived) {
    packetReceived = false;
    
    String message = "";
    while (LoRa.available()) {
      message += (char)LoRa.read();
    }
    
    Serial.print("Received: ");
    Serial.println(message);
    Serial.print("RSSI: ");
    Serial.println(LoRa.packetRssi());
  }
}

LoRa Com V2

Enhanced LoRa communication module with advanced features including mesh networking, half-duplex operation, and structured messaging.

Key Features

Multiple Operation Modes: Normal, half-duplex, and mesh
Structured Messages: Source/destination routing with message IDs
ACK System: Optional acknowledgment for reliable delivery
Node Discovery: Automatic mesh network discovery
Signal Quality: RSSI, SNR, and frequency error reporting
Buffering: 256-byte TX/RX buffers

Message Structure

lib/modules/communication/wireless/lora/lora-comv2.h

typedef struct {
    uint8_t msgType;      // MSG_DATA, MSG_ACK, MSG_COMMAND, MSG_BROADCAST, MSG_PING, MSG_PONG
    uint16_t sourceId;    // Source node ID
    uint16_t destId;      // Destination node ID
    uint16_t msgId;       // Message ID for tracking
    uint8_t ttl;          // Time to live (mesh hops)
    uint16_t payloadLen;  // Payload length
    char payload[240];    // Actual data
} LoRaMessage;

Configuration Structure

typedef struct {
    uint8_t cs;              // Chip select pin
    uint8_t rst;             // Reset pin
    uint8_t irq;             // Interrupt pin
    uint16_t nodeId;         // This node's ID
    long frequency;          // Operating frequency
    uint8_t spreadFactor;    // Spreading factor (7-12)
    long bandwidth;          // Bandwidth (125E3, 250E3, 500E3)
    uint8_t txPower;         // TX power (2-20 dBm)
    uint8_t syncWord;        // Sync word (default 0x12)
    uint16_t preambleLen;    // Preamble length
} LoRaConfig;

Basic Point-to-Point

#define ENABLE_MODULE_LORA_COM_V2
#include "Kinematrix.h"

#define LORA_CS_PIN    10
#define LORA_RESET_PIN 9
#define LORA_IRQ_PIN   2
#define LORA_FREQUENCY 915E6

LoRaComV2 lora;

void onInit() {
  Serial.println("LoRa initialized successfully!");
}

void setup() {
  Serial.begin(115200);
  
  // Initialize LoRa
  if (!lora.init(LORA_CS_PIN, LORA_RESET_PIN, LORA_IRQ_PIN, LORA_FREQUENCY, onInit)) {
    Serial.println("LoRa initialization failed!");
    while (1);
  }
  
  // Configure parameters
  lora.configure(
    8,       // Spreading factor
    125E3,   // Bandwidth
    17       // TX power (dBm)
  );
  
  lora.enableCRC();
  lora.setPreambleLength(8);
  
  Serial.println("LoRa ready");
}

void loop() {
  // Send data
  lora.clearData();
  lora.addData("TEMP");
  lora.addData(25.67);
  lora.addData("HUM");
  lora.addData(60.2);
  
  if (lora.sendData()) {
    Serial.println("Data sent");
  }
  
  delay(5000);
}

Bi-Directional Communication

example/modules/communication/wireless/lora/EXAMPLE-lora-comv2/lora-comv2_basic-send-receive-example/lora-comv2_basic-send-receive-example.ino

LoRaComV2 lora;
float temperature = 0.0;
float humidity = 0.0;

void onDataReceived(const String &data) {
  Serial.print("Data received: ");
  Serial.println(data);
  
  // Get signal quality
  Serial.print("RSSI: ");
  Serial.print(lora.packetRssi());
  Serial.print(" dBm, SNR: ");
  Serial.print(lora.packetSnr());
  Serial.println(" dB");
  
  // Parse received data
  String command = lora.getStrData(data, 0);
  
  if (command == "DATA_REQUEST") {
    // Send sensor data
    lora.clearData();
    lora.addData("SENSOR_DATA");
    lora.addData(temperature);
    lora.addData(humidity);
    delay(100);
    lora.sendData();
  }
  else if (command == "PING") {
    // Respond to ping
    lora.clearData();
    lora.addData("PONG");
    lora.addData(millis() / 1000);
    delay(50);
    lora.sendData();
  }
}

void loop() {
  // Check for incoming data
  lora.receive(onDataReceived);
  
  // Send periodic status updates
  static unsigned long lastSend = 0;
  if (millis() - lastSend > 8000) {
    lastSend = millis();
    
    lora.clearData();
    lora.addData("STATUS");
    lora.addData(temperature);
    lora.addData(humidity);
    lora.sendData();
  }
  
  delay(10);
}

Acknowledged Transmission

void loop() {
  lora.clearData();
  lora.addData("CRITICAL");
  lora.addData("Alert message");
  
  // Send with acknowledgment and retries
  if (lora.sendDataWithAck(1000, 3)) {
    Serial.println("Message acknowledged");
  } else {
    Serial.println("No acknowledgment received");
  }
  
  delay(10000);
}

Request-Response Pattern

void loop() {
  lora.clearData();
  lora.addData("GET_SENSOR");
  
  // Send request and wait for response
  String response = lora.sendDataAndWaitResponse(
    2000,  // 2-second timeout
    3      // Max 3 retries
  );
  
  if (response.length() > 0) {
    Serial.print("Response: ");
    Serial.println(response);
    
    float temp = lora.getData(response, 0);
    float humidity = lora.getData(response, 1);
  }
  
  delay(5000);
}

Half-Duplex Mode

Alternate between transmit and receive modes to avoid collisions:

void setup() {
  // ... initialization ...
  
  // Enable half-duplex mode with 1-second intervals
  lora.setMode(MODE_HALF_DUPLEX, 1000);
}

void onDataReceived(const String &data) {
  Serial.println("RX: " + data);
}

void onDataSent(const String &data) {
  Serial.println("TX: " + data);
}

void loop() {
  // Automatically switches between TX and RX
  lora.runHalfDuplexCycle(onDataReceived, onDataSent);
  
  // Queue data to send when in TX mode
  if (lora.isInTransmitState()) {
    lora.clearData();
    lora.addData("Sensor");
    lora.addData(analogRead(A0));
  }
}

Mesh Networking

void setup() {
  lora.init(LORA_CS_PIN, LORA_RESET_PIN, LORA_IRQ_PIN, LORA_FREQUENCY);
  lora.configure(8, 125E3, 17);
  
  // Enable mesh mode with node ID
  lora.enableMeshMode(101);  // This node is ID 101
  
  // Discover other nodes
  lora.discoverNodes(2);  // TTL=2 hops
}

void loop() {
  // Send to specific node in mesh
  lora.sendToMesh(
    102,                    // Destination node ID
    "Temperature: 25.5",   // Data
    3                       // TTL (max hops)
  );
  
  // Check known nodes
  uint8_t nodeCount = lora.getKnownNodeCount();
  Serial.print("Known nodes: ");
  Serial.println(nodeCount);
  
  for (uint8_t i = 0; i < nodeCount; i++) {
    Serial.print("  Node ID: ");
    Serial.println(lora.getKnownNodeId(i));
  }
  
  delay(10000);
}

Broadcast Messages

void loop() {
  // Broadcast to all nodes
  lora.broadcastMessage(
    "ALERT: System update",
    3  // TTL for mesh relay
  );
  
  delay(60000);  // Broadcast every minute
}

LoRa EByte E220

Specialized implementation for the EByte E220 LoRa module with advanced configuration capabilities.

Module Features

UART Interface: Serial communication with the module
Configuration Modes: Normal, WOR (Wake on Radio), sleep
Fixed/Broadcast: Address-based routing
RSSI Support: Signal strength monitoring
Structure Transmission: Send/receive C structs directly

Basic Configuration

#define ENABLE_MODULE_LORA_EBYTE_E220
#include "Kinematrix.h"

LoRaModuleEByteE220 lora(&Serial2, UART_BPS_RATE_9600);

void setup() {
  Serial.begin(115200);
  
  if (!lora.begin()) {
    Serial.println("E220 init failed!");
    while (1);
  }
  
  // Configure module
  lora.setAddress(0x00, 0x01);      // Address high/low
  lora.setChannel(23);               // Channel
  lora.setTransmissionPower(22);     // Max power
  lora.setAirDataRate(0b010);       // 2.4k bps
  lora.enableRSSI(true);             // Enable RSSI
  
  Serial.println("E220 ready");
}

Simple Message Transmission

void loop() {
  String message = "Temperature: " + String(25.5);
  
  if (lora.sendMessage(message)) {
    Serial.println("Message sent");
  } else {
    Serial.print("Error: ");
    Serial.println(lora.getLastError());
  }
  
  delay(5000);
}

Receive with RSSI

void loop() {
  if (lora.available()) {
    String message;
    int rssi;
    
    if (lora.receiveMessage(&message, &rssi)) {
      Serial.print("Received: ");
      Serial.println(message);
      Serial.print("RSSI: ");
      Serial.print(rssi);
      Serial.println(" dBm");
    }
  }
  
  delay(10);
}

Fixed Address Transmission

void loop() {
  // Send to specific address and channel
  lora.sendFixedMessage(
    0x00,              // Address high
    0x02,              // Address low
    23,                // Channel
    "Hello Node 2"    // Message
  );
  
  delay(5000);
}

Broadcast Transmission

void loop() {
  // Broadcast on channel 23
  lora.sendBroadcastMessage(23, "Broadcast message");
  delay(10000);
}

Structure Transmission

struct SensorData {
  float temperature;
  float humidity;
  uint32_t timestamp;
  uint8_t batteryLevel;
};

void loop() {
  SensorData data;
  data.temperature = 25.5;
  data.humidity = 60.2;
  data.timestamp = millis();
  data.batteryLevel = 85;
  
  // Send structure
  if (lora.sendStructure(data)) {
    Serial.println("Structure sent");
  }
  
  delay(5000);
}

// Receiver
void receiveStructure() {
  if (lora.available()) {
    SensorData data;
    int rssi;
    
    if (lora.receiveStructure(&data, &rssi)) {
      Serial.print("Temp: ");
      Serial.println(data.temperature);
      Serial.print("Humidity: ");
      Serial.println(data.humidity);
      Serial.print("RSSI: ");
      Serial.println(rssi);
    }
  }
}

WOR (Wake on Radio) Mode

void setup() {
  lora.begin();
  
  // Configure WOR for low power
  lora.configureWOR(0b011);  // WOR period
  
  Serial.println("WOR mode enabled");
}

LoRa Configuration Guide

Spreading Factor vs Range/Speed

SF	Data Rate	Range	Use Case
7	~5.5 kbps	Shortest	High-speed, short range
8	~3.1 kbps	Medium	Balanced
9	~1.8 kbps	Good	General purpose
10	~980 bps	Better	Long range
11	~440 bps	Excellent	Very long range
12	~250 bps	Maximum	Maximum range, slowest

Bandwidth Selection

// Wider bandwidth = faster data rate, shorter range
lora.setSignalBandwidth(500E3);  // Fast, short range
lora.setSignalBandwidth(250E3);  // Medium
lora.setSignalBandwidth(125E3);  // Slow, long range (default)

TX Power Configuration

// Higher power = longer range, more power consumption
lora.setTxPower(20);  // Maximum (100mW)
lora.setTxPower(17);  // High (50mW) - recommended
lora.setTxPower(14);  // Medium (25mW)
lora.setTxPower(10);  // Low (10mW) - for short range

Coding Rate

// Higher coding rate = more error correction, slower
lora.setCodingRate4(5);  // 4/5 (default)
lora.setCodingRate4(6);  // 4/6
lora.setCodingRate4(7);  // 4/7
lora.setCodingRate4(8);  // 4/8 - maximum error correction

Range Optimization

Maximum Range Configuration

// Optimize for maximum range
lora.setSpreadingFactor(12);      // Slowest, longest range
lora.setSignalBandwidth(125E3);   // Narrowest bandwidth
lora.setTxPower(20);               // Maximum power
lora.setCodingRate4(8);            // Maximum error correction
lora.setPreambleLength(12);        // Longer preamble
lora.enableCrc();                  // Enable error detection

Expected range: 10-15 km (line of sight) Data rate: ~250 bps

Balanced Configuration

// Balance between range and speed
lora.setSpreadingFactor(8);
lora.setSignalBandwidth(125E3);
lora.setTxPower(17);
lora.setCodingRate4(5);
lora.enableCrc();

Expected range: 2-5 km Data rate: ~3.1 kbps

Fast Data Configuration

// Optimize for speed (short range)
lora.setSpreadingFactor(7);
lora.setSignalBandwidth(500E3);
lora.setTxPower(14);
lora.setCodingRate4(5);

Expected range: 500m - 2km Data rate: ~21.9 kbps

Troubleshooting

Frequency Regulations: Ensure you’re using the correct frequency for your region:

US/Canada/South America: 915 MHz
Europe: 868 MHz
Asia: 433 MHz or 923 MHz

No Communication

Check:

Matching frequency on both devices
Matching spreading factor and bandwidth
Matching sync word
Antenna connected properly
Power supply adequate (3.3V, stable)

Debug:

Serial.print("Frequency: ");
Serial.println(lora.getSignalBandwidth());
Serial.print("SF: ");
Serial.println(lora.getSpreadingFactor());

Short Range

Possible causes:

Antenna issue (impedance mismatch, damaged)
Low TX power
High spreading factor not used
Obstacles blocking signal

Solutions:

Check antenna (50Ω impedance)
Increase TX power to 17-20 dBm
Increase spreading factor
Ensure line of sight

Data Corruption

Enable CRC and check signal quality:

lora.enableCrc();

// Check signal quality on receive
int rssi = lora.packetRssi();
float snr = lora.packetSnr();

if (rssi < -120) {
  Serial.println("Signal too weak");
}
if (snr < 0) {
  Serial.println("Noisy environment");
}

Best Practices

Duty Cycle: In Europe (868 MHz), adhere to 1% duty cycle regulations. For US (915 MHz), no duty cycle restrictions but be considerate.

Power Management: Use sleep mode between transmissions to conserve battery:

lora.sleep();  // Sleep mode
// ... wait ...
lora.idle();   // Wake up

Application Examples

Environmental Monitoring

Deploy sensor nodes across large areas (farms, forests)

Smart Agriculture

Soil moisture, weather stations, irrigation control

Asset Tracking

Long-range location tracking for vehicles or equipment

Disaster Communication

Emergency mesh networks when infrastructure fails

ESP-NOW

Alternative for shorter-range mesh networks

Modbus

Wired industrial communication protocol

Getting Started

Core Concepts

Sensor Framework

Communication

Control Algorithms

WiFi & Cloud Services

AutoLight System

Guides

​LoRa Modules Overview

LoRa Base

LoRa Com V2

LoRa EByte E220

​LoRa Specifications

​LoRa Base

​Hardware Configuration

​Basic Transmitter

​Basic Receiver

​Interrupt-Driven Reception

​LoRa Com V2

​Key Features

​Message Structure

​Configuration Structure

​Basic Point-to-Point

​Bi-Directional Communication

​Acknowledged Transmission

​Request-Response Pattern

​Half-Duplex Mode

​Mesh Networking

​Broadcast Messages

​LoRa EByte E220

​Module Features

​Basic Configuration

​Simple Message Transmission

​Receive with RSSI

​Fixed Address Transmission

​Broadcast Transmission

​Structure Transmission

​WOR (Wake on Radio) Mode

​LoRa Configuration Guide

​Spreading Factor vs Range/Speed

​Bandwidth Selection

​TX Power Configuration

​Coding Rate

​Range Optimization

​Troubleshooting

​Best Practices

​Application Examples

Environmental Monitoring

Smart Agriculture

Asset Tracking

Disaster Communication

​Related Modules

ESP-NOW

Modbus

Build docs developers (and LLMs) love

LoRa Modules Overview

LoRa Specifications

LoRa Base

Hardware Configuration

Basic Transmitter

Basic Receiver

Interrupt-Driven Reception

LoRa Com V2

Key Features

Message Structure

Configuration Structure

Basic Point-to-Point

Bi-Directional Communication

Acknowledged Transmission

Request-Response Pattern

Half-Duplex Mode

Mesh Networking

Broadcast Messages

LoRa EByte E220

Module Features

Basic Configuration

Simple Message Transmission

Receive with RSSI

Fixed Address Transmission

Broadcast Transmission

Structure Transmission

WOR (Wake on Radio) Mode

LoRa Configuration Guide

Spreading Factor vs Range/Speed

Bandwidth Selection

TX Power Configuration

Coding Rate

Range Optimization

Troubleshooting

Best Practices

Application Examples

Related Modules