Issue during duplex communication

[zolag63]

Hi, please help me out.

So i have two arduino nano, connected LoRa sx1278 units.

I use the to send: LoRa.beginPacket(); LoRa.write((uint8_t*)&data, sizeof(data)); LoRa.endPacket();

and to receive: int packetSize = LoRa.parsePacket(); if (packetSize){ LoRa-readBytes((unit8_t*), packetSize); }

What works: unit1 send to unit 2, unit 2 receive it. unit 2 send to unit 1, unit 1 receive it.

but if I would like to: unit1 send to unit 2 than wait for reply - meanwhile unit 2 receive than send

here the is just not works.

the code for the unit1:

include

include

byte program_state = 0; unsigned long pre_millis = 0;

struct payload { int id; int counter = 0; int rnd; }; typedef struct payload Package; Package data;

void setup() { Serial.begin(115200); while (!Serial); LoRa.setPins(8, 7); Serial.println("LoRa Sender");

if (!LoRa.begin(433E6)) { Serial.println("Starting LoRa failed!"); while (1); } LoRa.setSpreadingFactor(7); LoRa.setSignalBandwidth(62.5E3); }

void loop() { while (1) { switch (program_state) { case 0: if (millis() - pre_millis >= 1500) { id(); tx_msg(); data.counter++; pre_millis = millis(); } program_state = 1; break;

  case 1:
    rx_msg();
    program_state = 0;
    break;

  default:
    break;
}

} }

void id() { data.id += 1; if (data.id >= 5) { data.id = 0; } }

void rx_msg() { int packetSize = LoRa.parsePacket(); if (packetSize) { LoRa.readBytes((uint8_t*)&data, packetSize); Serial.print("; rnd: "); Serial.println(data.rnd); } }

void tx_msg() { LoRa.beginPacket(); LoRa.write((uint8_t*)&data, sizeof(data)); LoRa.endPacket(); Serial.print("Sending packet: "); Serial.print(data.counter); Serial.print(" to "); Serial.println(data.id); }

unit 2 code:

include

include

byte program_state = 0;

struct payload { int id = 3; int counter = 0; int rnd; }; typedef struct payload Package; Package data;

void setup() { Serial.begin(115200); while (!Serial);

Serial.println("LoRa Receiver"); LoRa.setPins(8, 7); if (!LoRa.begin(433E6)) { Serial.println("Starting LoRa failed!"); while (1); } LoRa.setSpreadingFactor(7); LoRa.setSignalBandwidth(62.5E3); }

void loop() { while (1) { switch (program_state) { case 0: rx_msg(); if (data.id == 3) prnt_msg(); program_state = 1; break;

  case 1:
    if (data.id == 8) {
      tx_msg();
    }
    data.id = 0;
    program_state = 0;
    break;

  default:
    break;
}

} }

void prnt_msg() { Serial.print("Received packet '"); Serial.print(data.counter); Serial.print("' with RSSI "); Serial.print(LoRa.packetRssi()); Serial.print("; SNR: "); Serial.println(LoRa.packetSnr()); }

void rx_msg() { int packetSize = LoRa.parsePacket(); if (packetSize) { LoRa.readBytes((uint8_t*)&data, packetSize); } }

void tx_msg() { data.rnd = random(12, 36000); Serial.print("; rnd: "); Serial.println(data.rnd); LoRa.beginPacket(); LoRa.write((uint8_t*)&data, sizeof(data)); LoRa.endPacket(); }

What do you think? why I cannot solve this? where is the problem?

[zolag63]

I found out. at the setPins() I have to declaire the dio0 as wel, so 2 variable not enough, If I don't use the 3rd one, it should be -1 something like this works: LoRa.setPins(8, 7, -1), this cause issue: LoRa.setPins(8, 7);

[universam1]

Thanks for updating with the solution