Untitled

/*
 * Lora to Lora (P2P) using RN2484 and ESP8266
 * This sketch will listen for any lora messages sent with correct SP, frequency, and other settings (see code below). 
 * An LED will blink every time a package is received. The received payload is printed on serial monitor. 
 * 
 * Code based on JP Meijers code from 30 September 2016
 * MN Petersen, Aug 2020
 * 
 * CONNECTIONS:
 * RN2483 - ESP8266:
 * TX     - GPIO18
 * RX     - GPIO19 
 * 3V3    - 3V3
 * GND    - GND
 * 
 * D7 on ESP8266 is connected to anode (long leg) on LED. Insert resistor between cathode and GND on ESP8266.
 * 
 */
 
#include <HardwareSerial.h>

// Define the RX and TX pins for the connection to the RN2484 module
#define RN2484_RX 18 // Example pin for RX, connect to TX of RN2484
#define RN2484_TX 19 // Example pin for TX, connect to RX of RN2484
#define RN2484_RST 23 //RESET PIN

// Initialize Serial2
HardwareSerial loraSerial(1); //BEGIN SERIAL ON UART1

String str;

void setup() {
  //output LED pin
  pinMode(LED_BUILTIN, OUTPUT);  // D7 on ESP8266
  led_off();
  
  // Open serial communications and wait for port to open:
  Serial.begin(57600);
  Serial.println("STARTUP!!!!"); //Startup print
  
  digitalWrite(RN2484_RST, LOW); // Resetting RN2483 by pulling RST pin low in 200 ms
  delay(200);
  digitalWrite(RN2484_RST, HIGH);
  
  loraSerial.begin(57600, SERIAL_8N1, RN2484_RX, RN2484_TX); //SETTING SERIAL UP
  loraSerial.setTimeout(1000);

  digitalWrite(RN2484_RST, LOW); // Resetting RN2483 by pulling RST pin low in 200 ms
  delay(200);
  digitalWrite(RN2484_RST, HIGH);

  lora_autobaud();
  
  led_on();
  delay(1000);
  led_off();

  Serial.println("Initing LoRa");
  
  // loraSerial.listen();
  //str = loraSerial.readStringUntil('\n');
  //Serial.println(str);
  loraSerial.println("sys get ver");
  str = loraSerial.readStringUntil('\n');
  Serial.print("Version: ");
  Serial.println(str);
  
  loraSerial.println("mac pause");
  str = loraSerial.readStringUntil('\n');
  Serial.println(str);
  
//  loraSerial.println("radio set bt 0.5");
//  wait_for_ok();
// Set the LoRa modulation, frequency, power, spreading factor, bandwidth, etc.
// Each command is followed by reading the response to ensure it was set correctly
  loraSerial.println("radio set mod lora");
  str = loraSerial.readStringUntil('\n');
  Serial.println(str);
  
  loraSerial.println("radio set freq 869100000");
  str = loraSerial.readStringUntil('\n');
  Serial.println(str);
  
  loraSerial.println("radio set pwr 14");
  str = loraSerial.readStringUntil('\n');
  Serial.println(str);
  
  loraSerial.println("radio set sf sf12");
  str = loraSerial.readStringUntil('\n');
  Serial.println(str);
  
  loraSerial.println("radio set afcbw 41.7");
  str = loraSerial.readStringUntil('\n');
  Serial.println(str);
  
  loraSerial.println("radio set rxbw 20.8");  // Receiver bandwidth can be adjusted here. Lower BW equals better link budget / SNR (less noise). 
  str = loraSerial.readStringUntil('\n');   // However, the system becomes more sensitive to frequency drift (due to temp) and PPM crystal inaccuracy. 
  Serial.println(str);
  
//  loraSerial.println("radio set bitrate 50000");
//  wait_for_ok();
  
//  loraSerial.println("radio set fdev 25000");
//  wait_for_ok();
  
  loraSerial.println("radio set prlen 8");
  str = loraSerial.readStringUntil('\n');
  Serial.println(str);
  
  loraSerial.println("radio set crc on");
  str = loraSerial.readStringUntil('\n');
  Serial.println(str);
  
  loraSerial.println("radio set iqi off");
  str = loraSerial.readStringUntil('\n');
  Serial.println(str);
  
  loraSerial.println("radio set cr 4/5"); // Maximum reliability is 4/8 ~ overhead ratio of 2.0
  str = loraSerial.readStringUntil('\n');
  Serial.println(str);
  
  loraSerial.println("radio set wdt 1000"); //disable for continuous reception
  str = loraSerial.readStringUntil('\n');
  Serial.println(str);
  
  loraSerial.println("radio set sync 12");
  str = loraSerial.readStringUntil('\n');
  Serial.println(str);
  
  loraSerial.println("radio set bw 125");
  str = loraSerial.readStringUntil('\n');
  Serial.println(str);
}

void loop() {
  Serial.println("waiting for a message");
  loraSerial.println("radio rx 0"); // Listen for incoming messages indefinitely
  str = loraSerial.readStringUntil('\n');
  Serial.println(str); // Print any initial response
  delay(20);
  
  // Check for "ok" response to ensure the radio is in receive mode
  if (str.indexOf("ok") == 0) {
    str = String(""); // Clear the string to prepare for receiving a message
    while (str == "") {
      str = loraSerial.readStringUntil('\n'); // Wait for a message
    }
    if (str.indexOf("radio_rx") == 0) { // Check if a message was received
      toggle_led(); // Toggle LED as visual indication of message reception
      Serial.println(str); // Print the received message
    } else {
      Serial.println("Received nothing"); // Indicate that no message was received
    }
  } else {
    Serial.println("radio not going into receive mode"); // Error handling
    delay(1000);
  }
}

void lora_autobaud() {
  String response = "";
  while (response == "") {
    delay(1000); // Wait a bit before trying again
    loraSerial.write((byte)0x00); // Send synchronization characters
    loraSerial.write(0x55);
    loraSerial.println(); // Ensure command line is terminated
    loraSerial.println("sys get ver"); // Attempt to get version as a way to confirm communication
    response = loraSerial.readStringUntil('\n');
  }
}

/*
 * This function blocks until the word "ok\n" is received on the UART,
 * or until a timeout of 3*5 seconds.
 */
int wait_for_ok()
{
  str = loraSerial.readStringUntil('\n');
  if ( str.indexOf("ok") == 0 ) {
    return 1;
  }
  else return 0;
}

void toggle_led()
{
  digitalWrite(LED_BUILTIN, 1);
  delay(100);
  digitalWrite(LED_BUILTIN, 0);
}

void led_on()
{
  digitalWrite(LED_BUILTIN, 1);
}

void led_off()
{
  digitalWrite(LED_BUILTIN, 0);
}