No packet received on receiver LoRa-02. Everything worked perfectly fine before

[Benedict-Bsl]

I have been testing LoRa-02 and using it for quite some time now. But recently i came across a bug which is some how tricky. i am using the "LoRaSender" and "LoRaReceiver" example code available in the library to send the "hello word + counter" packet and receiving it, both the receiver and transmitter at a frequency of 433mhz changed in the code from LoRa.begin(915E6) to LoRa.begin(433E6).

Everything worked perfectly fine before but a couple of days ago it just stopped receiving.... like nothing.

Sender code:

`#include

include

int counter = 0;

void setup() { Serial.begin(9600); while (!Serial);

Serial.println("LoRa Sender");

if (!LoRa.begin(433E6)) { Serial.println("Starting LoRa failed!"); while (1); } }

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

// send packet LoRa.beginPacket(); LoRa.print("hello "); LoRa.print(counter); LoRa.endPacket();

counter++;

delay(2000); }`

Receiver Code

`#include

include

void setup() { Serial.begin(9600); while (!Serial);

Serial.println("LoRa Receiver");

if (!LoRa.begin(433E6)) { Serial.println("Starting LoRa failed!"); while (1); } }

void loop() { // try to parse packet int packetSize = LoRa.parsePacket(); if (packetSize) { // received a packet Serial.print("Received packet '");

// read packet
while (LoRa.available()) {
  Serial.print((char)LoRa.read());
}

// print RSSI of packet
Serial.print("' with RSSI ");
Serial.println(LoRa.packetRssi());

} }`

Your help will greatly be appreciated. The library is Fantastic by the way!

[IoTThinks]

Hi, You can open an UART terminal to check if the LoRa setup succeeds. If it prints "Serial.println("Starting LoRa failed!");" then something is failed.

[Janadhii]

Hello, Did you find any solution? I also have the same problem of not receiving packets. The Sender works fine ! Thanks.

[NgHieuPickon]

Hello, I fixed it. In funchion endPacket (LoRa.ccp):

int LoRaClass::endPacket(bool async)
{
  // put in TX mode
  writeRegister(REG_OP_MODE, MODE_LONG_RANGE_MODE | MODE_TX);

  if (async) {
    // grace time is required for the radio
    delayMicroseconds(150);
  } else {
    // wait for TX done
    while ((readRegister(REG_IRQ_FLAGS) & IRQ_TX_DONE_MASK) == 0) {
      yield();
    }
    // clear IRQ's
    writeRegister(REG_IRQ_FLAGS, IRQ_TX_DONE_MASK);
  }
  return 1;
}

if you trans and receive very fast, the program will stop in "while" => break it!

i have edited that:

  if (async) {
    // grace time is required for the radio
    delayMicroseconds(150);
  } else {
    // wait for TX done
    int fix = 0;
    while ((readRegister(REG_IRQ_FLAGS) & IRQ_TX_DONE_MASK) == 0) {
      yield();
      Serial.println("hehe");
      fix++;
      delay(1);
      if(fix > 100){
          writeRegister(REG_IRQ_FLAGS, IRQ_TX_DONE_MASK);
          return 0;
      }
    }
    // clear IRQ's
    writeRegister(REG_IRQ_FLAGS, IRQ_TX_DONE_MASK);
  }

And in Arduino:

          LoRa_txMode();          
          LoRa.beginPacket();          
          LoRa.print(Res);          // Res is message, type String.
          if (LoRa.endPacket() == 0) {
            Serial.println("error endPacket!");  //print error
          }          
          LoRa_rxMode();

English isn't my first language, so please excuse my mistakes!

[orimate]

Hi, are LoRa_txMode(); LoRa_rxMode() your own functions? Should be not called LoRa.endPacket(); after LoRa.print(Res); ?