Documentation

// Ra-02 SX1278 - LoRa Sender (Arduino IDE)
// Library: "LoRa" by Sandeep Mistry (Library Manager)
// ESP32 pins: NSS=5, RESET=14, DIO0=26 (change for your wiring)

#include <SPI.h>
#include <LoRa.h>

const long FREQ = 433E6;
int counter = 0;

void setup() {
  Serial.begin(115200);
  LoRa.setPins(5, 14, 26);          // NSS, RESET, DIO0

  if (!LoRa.begin(FREQ)) {
    Serial.println("LoRa init failed - check wiring/antenna!");
    while (1);
  }
  LoRa.setSpreadingFactor(9);       // 7 = fast, 12 = max range
  LoRa.setSignalBandwidth(125E3);
  LoRa.setTxPower(17);              // dBm (max 20)
  LoRa.setSyncWord(0x12);           // private-network marker
  Serial.println("LoRa sender ready");
}

void loop() {
  Serial.print("Sending packet ");
  Serial.println(counter);

  LoRa.beginPacket();
  LoRa.print("Hello #");
  LoRa.print(counter++);
  LoRa.endPacket();

  delay(2000);
}

// Ra-02 SX1278 - LoRa Receiver (Arduino IDE)
// Same library and settings as the sender.

#include <SPI.h>
#include <LoRa.h>

void setup() {
  Serial.begin(115200);
  LoRa.setPins(5, 14, 26);

  if (!LoRa.begin(433E6)) {
    Serial.println("LoRa init failed!");
    while (1);
  }
  LoRa.setSpreadingFactor(9);
  LoRa.setSignalBandwidth(125E3);
  LoRa.setSyncWord(0x12);
  Serial.println("LoRa receiver ready");
}

void loop() {
  int packetSize = LoRa.parsePacket();
  if (packetSize) {
    String msg = "";
    while (LoRa.available()) {
      msg += (char)LoRa.read();
    }
    Serial.print("Received: '");
    Serial.print(msg);
    Serial.print("'  RSSI: ");
    Serial.print(LoRa.packetRssi());
    Serial.print(" dBm  SNR: ");
    Serial.println(LoRa.packetSnr());
  }
}

#!/usr/bin/env python3
# Ra-02 SX1278 - Raspberry Pi LoRa receiver (pyLoRa)
# Install: pip3 install pyLoRa spidev RPi.GPIO
# Wiring: NSS->CE0, RESET->GPIO22, DIO0->GPIO24 (BOARD mode in lib config)

from SX127x.LoRa import LoRa
from SX127x.board_config import BOARD
import time

BOARD.setup()

class Receiver(LoRa):
    def __init__(self):
        super(Receiver, self).__init__(verbose=False)
        self.set_mode(0x80)          # sleep, LoRa mode
        self.set_freq(433.0)
        self.set_spreading_factor(9)
        self.set_bw(7)               # 7 = 125 kHz
        self.set_sync_word(0x12)
        self.set_rx_crc(True)

    def on_rx_done(self):
        payload = self.read_payload(nocheck=True)
        text = bytes(payload).decode(errors="ignore")
        print("Received: '{}'  RSSI: {} dBm".format(
            text, self.get_pkt_rssi_value()))
        self.set_mode(0x85)          # back to RX continuous

lora = Receiver()
print("LoRa receiver ready (433 MHz, SF9)")
lora.set_mode(0x85)                  # RX continuous

try:
    while True:
        time.sleep(0.5)
except KeyboardInterrupt:
    BOARD.teardown()
    print("Stopped by user")

# Ra-02 SX1278 - Pico MicroPython sender
# Driver: copy sx127x.py from the micropython-lora project
#   (github.com/martynwheeler/u-lora or similar sx127x.py) to the Pico
# Wiring: SCK=GP2, MOSI=GP3, MISO=GP4, NSS=GP5, RESET=GP6, DIO0=GP7

from machine import Pin, SPI
from sx127x import SX127x
import time

lora_cfg = {
    "frequency": 433E6,
    "spreading_factor": 9,
    "signal_bandwidth": 125E3,
    "tx_power_level": 17,
    "sync_word": 0x12,
}

spi = SPI(0, baudrate=5_000_000,
          sck=Pin(2), mosi=Pin(3), miso=Pin(4))

lora = SX127x(spi,
              pins={"ss": 5, "reset": 6, "dio_0": 7},
              parameters=lora_cfg)

counter = 0
print("LoRa sender ready (433 MHz, SF9)")
while True:
    msg = "Pico #{}".format(counter)
    print("Sending:", msg)
    lora.println(msg)
    counter += 1
    time.sleep(2)