Using the “Wio-SX1262 for XIAO” to easily build LoRa point-to-point communication with various XIAOs

[PJ_Glasso]

Hi there,

So I got the Open Receiver code up on the Dev Expansion Board, Displays “Beacon Message” on first line and is sent in // REV 5.5b - SX1262 Beacon Sender with LED + Button + Power Modes // Posted below.
Press the button to send message with different power levels…
on the Sender (beacon) intervals of 2 dB Transmit power. Watch display on Open receiver and note the RSSI & SNR .
(next experiment will be a press button on each end to change modes.)
OPEN Receiver:

// REV 5.6n - SX1262 Open Receiver with OLED Display
// Board: ESP32-S3 with SX1262 LoRa Module + OLED (XIAO Expansion Board)
// Receives LoRa messages and displays: 
//   1) Beacon Message (1st line)
//   2) RSSI and SNR values (formatted & centered)
//   3) Blinks onboard LED (GPIO 48) on message reception
//   4) Serial output stays consistent with previous 5.5b version

#include <RadioLib.h>
#include <Wire.h>
#include <U8g2lib.h>

// SX1262 Module Pins: NSS, DIO1, RST, BUSY
SX1262 radio = new Module(41, 39, 42, 40);

// OLED: I2C (128x64), flipped orientation (USB on right side)
U8G2_SSD1306_128X64_NONAME_F_HW_I2C display(U8G2_R0, U8X8_PIN_NONE);

// LED for RX activity
const int LED_PIN = 48;

// Last received values for change detection
float lastRSSI = 0;
float lastSNR = 0;
String lastMsg = "";

// Thresholds for display update
const float RSSI_THRESHOLD = 0.25;
const float SNR_THRESHOLD = 0.25;

void setup() {
  pinMode(LED_PIN, OUTPUT);
  digitalWrite(LED_PIN, LOW);

  Serial.begin(115200);
  delay(500);
  Serial.println();
  Serial.println(F("// REV 5.6n - SX1262 Open Receiver with OLED Display"));
  Serial.println(F("// Board: ESP32-S3 with SX1262 LoRa Module + OLED"));
  Serial.print(F("Initializing SX1262 LoRa radio... "));

  if (radio.begin() != RADIOLIB_ERR_NONE) {
    Serial.println(F("FAILED!"));
    while (true);
  }
  Serial.println(F("SUCCESS!"));
  Serial.println(F("Listening for LoRa messages..."));

  // LoRa radio config
  radio.setOutputPower(22);
  radio.setSpreadingFactor(7);
  radio.setBandwidth(125.0);
  radio.setCodingRate(5);

  // OLED startup screen
  display.begin();
  display.setFlipMode(1);  // Flip vertically for correct orientation
  display.clearBuffer();
  display.setFont(u8g2_font_6x12_tf);
  display.setCursor(0, 12);
  display.print("SX1262 Open Receiver");
  display.setCursor(0, 28);
  display.print("XIAO S3 + OLED");
  display.setCursor(0, 44);
  display.print("REV 5.6n");
  display.sendBuffer();
  delay(2000);

  // Initial Listening Screen
  display.clearBuffer();
  display.setCursor(0, 12);
  display.print("Listening...");
  display.sendBuffer();
}

void loop() {
  String msg;
  int state = radio.receive(msg);

  if (state == RADIOLIB_ERR_NONE) {
    float rssi = radio.getRSSI();
    float snr = radio.getSNR();
    bool updated = false;

    if (msg != lastMsg) {
      Serial.print("Received: ");
      Serial.println(msg);
      lastMsg = msg;
      updated = true;
    }

    if (abs(rssi - lastRSSI) > RSSI_THRESHOLD || abs(snr - lastSNR) > SNR_THRESHOLD) {
      Serial.print("  RSSI: ");
      Serial.print(rssi, 2);
      Serial.print(" dBm\tSNR: ");
      Serial.print(snr, 2);
      Serial.println(" dB");
      lastRSSI = rssi;
      lastSNR = snr;
      updated = true;
    } else {
      Serial.print(".");
    }

    if (updated) {
      display.clearBuffer();
      display.setFont(u8g2_font_6x12_tf);
      display.setCursor(0, 12);
      display.print(lastMsg);  // Line 1

      display.setCursor(0, 28);
      display.print("  RSSI    -    SNR");  // Line 3

      display.setFont(u8g2_font_7x13B_tf);
      display.setCursor(10, 44);
      display.printf("%.0f", lastRSSI);
      display.setCursor(74, 44);
      display.printf("%.2f", lastSNR);

      display.setFont(u8g2_font_6x12_tf);
      display.setCursor(15, 60);
      display.print("dBm");
      display.setCursor(86, 60);
      display.print("dB");

      display.sendBuffer();
    }

    digitalWrite(LED_PIN, HIGH);
    delay(30);
    digitalWrite(LED_PIN, LOW);
  }
}

Serial output for receiver ;

// REV 5.6n - SX1262 Open Receiver with OLED Display
// Board: ESP32-S3 with SX1262 LoRa Module + OLED
Initializing SX1262 LoRa radio... SUCCESS!
Listening for LoRa messages...
Received: Seeed Studio
  RSSI: -125.00 dBm	SNR: -9.25 dB

// REV 5.6n - SX1262 Open Receiver with OLED Display
// Board: ESP32-S3 with SX1262 LoRa Module + OLED
Initializing SX1262 LoRa radio... SUCCESS!
Listening for LoRa messages...
Received: Seeed Studio
  RSSI: -125.00 dBm	SNR: -8.75 dB
.  RSSI: -125.00 dBm	SNR: -9.25 dB
  RSSI: -125.00 dBm	SNR: -8.75 dB
.  RSSI: -125.00 dBm	SNR: -9.25 dB
...  RSSI: -125.00 dBm	SNR: -8.50 dB
  RSSI: -125.00 dBm	SNR: -9.25 dB
  RSSI: -126.00 dBm	SNR: -9.50 dB
.  RSSI: -125.00 dBm	SNR: -9.25 dB
..  RSSI: -126.00 dBm	SNR: -9.50 dB
  RSSI: -125.00 dBm	SNR: -9.25 dB
  RSSI: -126.00 dBm	SNR: -9.50 dB
  RSSI: -126.00 dBm	SNR: -10.50 dB
  RSSI: -125.00 dBm	SNR: -8.75 dB
  RSSI: -126.00 dBm	SNR: -9.75 dB
.  RSSI: -125.00 dBm	SNR: -8.50 dB
  RSSI: -125.00 dBm	SNR: -9.00 dB
.
  RSSI: -115.00 dBm	SNR: 1.25 dB
  RSSI: -115.00 dBm	SNR: 1.75 dB
  RSSI: -115.00 dBm	SNR: 1.25 dB
  RSSI: -113.00 dBm	SNR: 3.50 dB
  RSSI: -117.00 dBm	SNR: -0.50 dB
  RSSI: -114.00 dBm	SNR: 2.00 dB
.....  RSSI: -114.00 dBm	SNR: 2.50 dB
  RSSI: -114.00 dBm	SNR: 2.00 dB
..  RSSI: -115.00 dBm	SNR: 1.25 dB
  RSSI: -114.00 dBm	SNR: 1.75 dB
  RSSI: -116.00 dBm	SNR: 0.25 dB
  RSSI: -114.00 dBm	SNR: 2.25 dB
.....  RSSI: -114.00 dBm	SNR: 1.75 dB
  RSSI: -115.00 dBm	SNR: 1.25 dB
  RSSI: -114.00 dBm	SNR: 2.00 dB
.....  RSSI: -113.00 dBm	SNR: 2.50 dB
  RSSI: -114.00 dBm	SNR: 2.00 dB
..  RSSI: -114.00 dBm	SNR: 2.50 dB
..  RSSI: -113.00 dBm	SNR: 2.75 dB
  RSSI: -114.00 dBm	SNR: 2.50 dB
.  RSSI: -114.00 dBm	SNR: 2.00 dB
  RSSI: -114.00 dBm	SNR: 2.50 dB
....  RSSI: -115.00 dBm	SNR: 1.00 dB
  RSSI: -113.00 dBm	SNR: 3.00 dB
  RSSI: -110.00 dBm	SNR: 5.75 dB
  RSSI: -108.00 dBm	SNR: 7.00 dB
...............................  RSSI: -109.00 dBm	SNR: 6.25 dB
  RSSI: -108.00 dBm	SNR: 7.25 dB
  RSSI: -109.00 dBm	SNR: 6.50 dB
.  RSSI: -108.00 dBm	SNR: 6.75 dB
.  RSSI: -109.00 dBm	SNR: 6.25 dB
  RSSI: -108.00 dBm	SNR: 7.25 dB
................  RSSI: -107.00 dBm	SNR: 7.25 dB
  RSSI: -109.00 dBm	SNR: 6.25 dB
  RSSI: -108.00 dBm	SNR: 7.25 dB
..  RSSI: -108.00 dBm	SNR: 6.75 dB
.  RSSI: -109.00 dBm	SNR: 7.00 dB
..  RSSI: -108.00 dBm	SNR: 6.50 dB
.  RSSI: -108.00 dBm	SNR: 7.00 dB
.................

Beacon Sender…:

// REV 5.5b - SX1262 Beacon Sender with LED + Button + Power Modes
// Board: ESP32-S3 with SX1262 LoRa Module
// Sends "Seeed Studio" as beacon every 5 seconds
// LED on GPIO 48 blinks on TX
// Button on GPIO 21 cycles TX power level (2 to 22 dBm)

#include <RadioLib.h>

#define NSS     41
#define DIO1    39
#define RST     42
#define BUSY    40
#define LED_PIN 48
#define BTN_PIN 21

SX1262 radio = new Module(NSS, DIO1, RST, BUSY);

const char beaconMessage[] = "Seeed Studio";
int txPower = 22;
unsigned long lastSendTime = 0;
const unsigned long beaconInterval = 5000;

int lastButtonState = HIGH;
bool firstPrint = true;

void setup() {
  pinMode(LED_PIN, OUTPUT);
  pinMode(BTN_PIN, INPUT_PULLUP);
  digitalWrite(LED_PIN, LOW);

  Serial.begin(115200);
  delay(1000);
  Serial.println();
  Serial.println("// REV 5.5b - SX1262 Beacon Sender");
  Serial.println("// Board: ESP32-S3 with SX1262 LoRa Module");
  Serial.print("Initializing SX1262 LoRa radio... ");

  if (radio.begin() != RADIOLIB_ERR_NONE) {
    Serial.println("FAILED!");
    while (true);
  }

  Serial.println("SUCCESS!");
  radio.setOutputPower(txPower);
  radio.setSpreadingFactor(7);
  radio.setBandwidth(125.0);
  radio.setCodingRate(5);

  Serial.print("TX Power: ");
  Serial.print(txPower);
  Serial.println(" dBm");
  Serial.println("Beacon message: \"Seeed Studio\"");
  Serial.println("Transmitting every 5 seconds...\n");
}

void loop() {
  unsigned long now = millis();

  // Button handling to change TX power
  int btnState = digitalRead(BTN_PIN);
  if (btnState == LOW && lastButtonState == HIGH) {
    txPower += 2;
    if (txPower > 22) txPower = 2;
    radio.setOutputPower(txPower);
    Serial.print("\nTX Power changed to: ");
    Serial.print(txPower);
    Serial.println(" dBm");
    delay(250);  // debounce
  }
  lastButtonState = btnState;

  // Send beacon every interval
  if (now - lastSendTime >= beaconInterval) {
    lastSendTime = now;

    digitalWrite(LED_PIN, HIGH);
    int state = radio.transmit(beaconMessage);
    digitalWrite(LED_PIN, LOW);

    if (state == RADIOLIB_ERR_NONE) {
      if (firstPrint) {
        Serial.print("Sent: ");
        Serial.println(beaconMessage);
        firstPrint = false;
      } else {
        Serial.print(".");
      }

      static int dotCount = 0;
      dotCount++;
      if (dotCount % 80 == 0) Serial.println();
    } else {
      Serial.print("Transmit failed, code ");
      Serial.println(state);
    }
  }
}

Sender Serial Output.:

// REV 5.5b - SX1262 Beacon Sender
// Board: ESP32-S3 with SX1262 LoRa Module
Initializing SX1262 LoRa radio... SUCCESS!
TX Power: 22 dBm
Beacon message: "Seeed Studio"
Transmitting every 5 seconds...

Sent: Seeed Studio
...............................................................................
................................................................................
................................................................................
.......................................................................
TX Power changed to: 2 dBm
.........
.
TX Power changed to: 4 dBm
.....
TX Power changed to: 6 dBm
...
TX Power changed to: 8 dBm
..........
TX Power changed to: 10 dBm
....
TX Power changed to: 12 dBm
.............................................
TX Power changed to: 14 dBm

TX Power changed to: 16 dBm
.
TX Power changed to: 18 dBm

TX Power changed to: 20 dBm

TX Power changed to: 22 dBm
...
TX Power changed to: 2 dBm
........
................................................................................
........................................................
// REV 5.5b - SX1262 Beacon Sender
// Board: ESP32-S3 with SX1262 LoRa Module
Initializing SX1262 LoRa radio... SUCCESS!
TX Power: 22 dBm
Beacon message: "Seeed Studio"
Transmitting every 5 seconds...

Sent: Seeed Studio
...............................................................................
...................................

Starts at 22 dBm , press button goes to 2,4,6,8, etc…

HTH
GL PJ
Like, Share and subscribe… LOL

[msfujino]

A point-to-point long distance communication experiment was carried out with XIAO_MG24 mounted on Wio-SX1262 for XIAO. The main parameters are: frequency 922.6[MHz], Txpower=13[dBm], bw=125[kHz], sf=12, cr=5, antenna λ/2.
Stable communication was achieved with RSSI=-127[dBm] and SNR=-15[dB] over a line of sight of 24.5[km].

This was the same as the results of the experiment with LoRa-E5 mini shown in the link below.

Here is the sketch I used for the experiment. The sketch should be easily modified for other XIAOs.
POST_SX1262_MG24_P2P.zip (8.5 KB)

Programming LoRa-E5 with Arduino, LoRa-E5 mini Point to Point Comminucation over 24 km

In my previous experiments I had been able to achieve a communication distance of 10 km. To further extend the communication distance, I used Google Map to find a line-of-sight route. The result was communication over a distance of 24.5 km, RSSI below the measurement limit of -127[dBm], and SNR of -15[dB]. However, it was susceptible to noise, and every time a truck passed by Slave, communication was lost or a verify error occurred, so I think 24 km is the limit. The procedure is, Slave send…

[PJ_Glasso]

Hi there,

Bro , the Use of the cardboard is simply BAdA$$, man way to use what you got just shows with some vision what one can achieve…

GL PJ

Are those Seeed Studio Antennas? on web site?

[cgwaltney]

Nice Pigtails… and I dont mean your hair…

Have you tried LoRa Board with Round Display… I dont think it will work because they use the SPI bus?.. also GPS mated? also Graphics Driver Issue I wonder if a Daughter Board could be created to remap pins between layers

the ESP32S3 may work with a IIC GPS

I dont know if meshtastic supports color display

[PJ_Glasso]

Hi there,

Round will work, Just needs correct config on the buss. the new unit is good that it uses the B2B connector. Someone posted they had it working with the Clock Demo, but I never saw any code, so YMMV
I don’t see a reason it wouldn’t in present form WIO-SX1262 & S3
The open Receiver code demo uses the Dev expansion board OLED straight away no issues. Same with Grove Expansion with the SD1306 I2C Cheep display.

I’ll wack & Chop something up for it, eventually.
HTH
GL PJ

[msfujino]

@PJ_Glasso

Are those Seeed Studio Antennas? on web site?

The antenna was included with the LoRa-E5 mini.

Remembering my granddaughter’s craft, I fixed the antenna with cardboard.
It was enough for about an hour of experimentation.

[msfujino]

There was a problem with interrupts during reception, so the sketch has been updated.

POST_SX1262_MMG24_P2P_1.zip (8.5 KB)

[msfujino]

There are sketches for long distance communication experiments with various XIAOs.I think these will work with any master/slave combination.
If you are interested, please use them.

SX1262_XIAOs_P2P_MasterSlave.zip (46.2 KB)