Module LoRa868 v1.2 Arduino Usage Tutorial

#include <Arduino.h>
#include <M5GFX.h>
#include <M5Unified.h>
#include <RadioLib.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
 
#define LORA_BW 500.0
#define LORA_SF 7
#define LORA_CR 8
 
#define LORA_FREQ         868.0
#define LORA_SYNC_WORD    0x34
#define LORA_TX_POWER     22
#define LORA_PREAMBLE_LEN 20
 
#define CONFIG_MISO_GPIO GPIO_NUM_35
#define CONFIG_MOSI_GPIO GPIO_NUM_37
#define CONFIG_SCLK_GPIO GPIO_NUM_36
 
#define CONFIG_LORA_NSS  GPIO_NUM_1
#define CONFIG_LORA_BUSY GPIO_NUM_2
#define CONFIG_LORA_RST  GPIO_NUM_7
#define CONFIG_LORA_IRQ  GPIO_NUM_10
 
SX1262 *radio = NULL;
 
// save transmission states between loops
int transmissionState = RADIOLIB_ERR_NONE;
 
// flag to indicate transmission or reception state
bool transmitFlag = false;
 
volatile bool operationDone = false;
 
ICACHE_RAM_ATTR void setFlag(void)
{
    // we sent or received a packet, set the flag
    operationDone = true;
}
 
void lora_init()
{
    radio = new SX1262(new Module(CONFIG_LORA_NSS,     // NSS
                                  CONFIG_LORA_IRQ,     // DIO1
                                  CONFIG_LORA_RST,     // RST
                                  CONFIG_LORA_BUSY));  // BUSY
 
    M5.Display.println("LoRa init...");
 
    //   RADIOLIB_ERR_NONE
    int state = radio->begin(LORA_FREQ, LORA_BW, LORA_SF, LORA_CR, LORA_SYNC_WORD, LORA_TX_POWER, LORA_PREAMBLE_LEN,
                             3.0, false);
 
    radio->setDio1Action(setFlag);
 
    Serial.print(F("Starting to listen ... "));
    state = radio->startReceive();
    if (state == RADIOLIB_ERR_NONE) {
        Serial.println(F("success!"));
        M5.Display.println("LoRa init success");
        M5.Display.println("Touch to send packet");
    } else {
        Serial.print(F("failed, code "));
        M5.Display.println("LoRa init failed");
        Serial.println(state);
        while (true) {
            delay(10);
        }
    }
}
 
void setup()
{
    M5.begin();
    Serial.begin(115200);
    M5.Display.setTextColor(YELLOW);
    M5.Display.setFont(&fonts::FreeSansBold9pt7b);
    M5.Display.setTextScroll(true);
    lora_init();
}
 
int msg_count = 0;
String tx_payload;
String rx_payload;
void loop()
{
    M5.update();
    auto t = M5.Touch.getDetail();
 
    if (t.wasClicked() || M5.BtnA.wasClicked()) {
        // send another one
        msg_count++;
        Serial.print(F("Sending another packet ... "));
 
        tx_payload = "Hello LoRa Count: " + String(msg_count);
        transmissionState = radio->transmit(tx_payload);
        M5.Display.println("Sending packet!");
        M5.Display.println(tx_payload);
        transmitFlag = true;
    }
    // check if the previous operation finished
    if (operationDone) {
        // reset flag
        operationDone = false;
        if (transmitFlag) {
            transmitFlag = false;
            int state    = radio->startReceive();
        } else {
            int state = radio->readData(rx_payload);
            Serial.println("lora_rx_flag");
            Serial.println(state);
            if (state == RADIOLIB_ERR_NONE) {
                // packet was successfully received
                Serial.println(F("Received packet!"));
 
                // print data of the packet
                Serial.print(F("Data:\t\t"));
                Serial.println(rx_payload);
 
                // print RSSI (Received Signal Strength Indicator)
                Serial.print(F("RSSI:\t\t"));
                Serial.print(radio->getRSSI());
                Serial.println(F(" dBm"));
 
                // print packet length
                Serial.print(F("Length:\t\t"));
                Serial.print(radio->getPacketLength());
 
                // print SNR (Signal-to-Noise Ratio)
                Serial.print(F("SNR:\t\t"));
                Serial.print(radio->getSNR());
                Serial.println(F(" dB"));
 
                // display on screen
                M5.Display.println("Received packet!");
                M5.Display.println("Data:");
                M5.Display.println(rx_payload);
                M5.Display.print("RSSI:");
                M5.Display.print(radio->getRSSI());
                M5.Display.println(" dBm");
                M5.Display.print("SNR:");
                M5.Display.print(radio->getSNR());
                M5.Display.println(" dB");
            }
        }
    }
}