Arduino LORA Send and Receive Data - arduino

Question

I tried to allow sending and receiving data using 2 Arduino Unos, 2 LORA chips (SX1278 433MHz), 2 antennas and 2 Arduino IDE.
Problem is with the receiving data command.
This is the code for SENDING command:
#include <SPI.h>
#include <LoRa.h>
int counter = 0;
const int ss = 10;
const int reset = 9;
const int dio0 = 2;
void setup() {
Serial.begin(9600);
LoRa.begin(433E6);
LoRa.setPins(ss, reset, dio0);
while (!Serial);
Serial.println("LoRa Sender");
}
void loop() {
Serial.print("Sending packet: ");
Serial.println(counter);
// send packet
LoRa.beginPacket();
LoRa.print("hello ");
LoRa.print(counter);
LoRa.endPacket();
counter++;
delay(5000);
}
On serial monitor, I succeed in sending packages, but not receiving. This is the RECEIVING code:
#include <SPI.h>
#include <LoRa.h>
const int ss = 10;
const int reset = 9;
const int dio0 = 2;
void setup() {
Serial.begin(9600);
LoRa.begin(433E6);
LoRa.setPins(ss, reset, dio0);
while (!Serial);
Serial.println("LoRa Receiver");
}
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());
Serial.print("hello ");
}
// print RSSI of packet
Serial.print("' with RSSI ");
Serial.println(LoRa.packetRssi());
}
}
I used instructions about connections from this git page:
https://github.com/sandeepmistry/arduino-LoRa

Answer 1

To make this board work, I had to explicitly initialize SPI
SPI.begin(/*sck*/ 5, /*miso*/ 19, /*mosi*/ 27, /*ss*/ cs);
It may be the same for yours. Also, you should properly initialize Lora:
while (!LoRa.begin(433E6)) {
Serial.print(".");
delay(500);
}
Serial.println("LoRa Initializing OK!");
With the code you posted, you don't really know if it initialized correcly or if it's actually sending any data.

Answer 2

First I haven't worked with Lora library. I worked with SX1278 libaray. So I can help you with that.
At first here is the link to the libaray - Lora SX1278.h library
Now you might ask why I'm not using the library from the original GitHub repo. Well I faced issue with that library and the issue is this:
The sx1278::getPacket() library function is modified to stabilize the Lora receive functionality. There was a bug which led the esp to panic. The payloadlength read from the REG_FIFO register was not checked for valid value which led to reading the REG_FIFO register read for over 65000 times. Moreover yield() is added in time consuming parts of this function.
That is why I'm using this custom library. Anyway, for you:
You can use this function to send packet:
T_packet_state = sx1278.sendPacketTimeoutACK(ControllerAddress, message); //T_packet_state is 0 if the packet data is sent successful.
Also to receive data use this function:
R_packet_state = sx1278.receivePacketTimeoutACK(); //R_packet_state is 0 if the packet data is received successfully.
And at the beginning of the code just define this few things:
//Lora SX1278:
#define LORA_MODE 10 //Add your suitable mode from the library
#define LORA_CHANNEL CH_6_BW_125 //Ch number and Bandwidth
#define LORA_ADDRESS 3 //Address of the device from which you will send data
uint8_t ControllerAddress = 5; //Address of receiving end device
My first decent answer on StackOverflow. Finger Crossed