Unable to get Reyax RYLR896 module working

Products & Technology LoRa
#1

Hello, I hope it is okay to post a question like this on this forum, as this is not regarding a Seeed product. I’m still getting familiar.

I’m making an attempt to use a Reyax RYLR896 module, however it is not working. Any input would be much appreciated.

I have looked at a number of tutorials, both video and text, and have tried to boil it down to a simple proof-of-concept design.

The connections seem quite simple:

Arduino - RYLR896:
3.3v to Vdd
gnd to gnd
Tx to Rx (through 5v to 3.3v voltage divider)
Rx to Tx

Here is the wiring diagram I followed: (Note: I used a 5K5 instead of 4K7 so the voltage wouldn’t be over 3.3V.)

RYLR896_wiring
RYLR896_wiring1020×796 67.1 KB

This is my code. It reads a “sensor” (translate: variable resistor.) Distilled from this page:

(Note however, I could not get the code as written in the article to work either. I also tried another example which used SoftwareSerial, but couldn’t get it to work either.)

Transmitter:

int vresistor = A0; 

void setup() {
  Serial.begin(115200); 
  pinMode(vresistor,INPUT); 
}

void loop() {
  int sensorvalue = analogRead(vresistor);
  String sensorvaluestr = String(sensorvalue);
  String datalength = String(sensorvaluestr.length());

  String mymessage = "AT+SEND=0," + datalength + "," + sensorvaluestr + "\r\n";
  
  Serial.println(mymessage); 

  delay(100); 
}

Receiver:

void setup() {
  Serial.begin(115200); 
  Serial.print("AT\r\n");
  delay(100); 
}

void loop() {
  if (Serial.available()) { 
    String rcvdData = Serial.readString();
    Serial.println(rcvdData); 
  }
}

Note: I have since realized the use of Strings is not recommended and not needed here, but this should give an idea of what I have done.

I have also attempted to communicate with the RYLR896 using AT commands per this video tutorial:

Per instruction on the tutorial, I reversed the Tx/Rx connections on the Arduino (now Tx on Arduino to Tx on transceiver; Rx on Arduino to Rx on transceiver, through voltage divider,) have baud of the serial monitor set at 115200, and line endings set to “Both NL & CR”. I send the command “AT” expecting “+OK” in return, I get no responses, not even an error. Sending “AT+ADDRESS?” gives no response either.

I purchased 2 modules when I started this, and have the same results with both.

I’m beginning to wonder if I have bad modules or bad luck.

The aforementioned video instructed to remove the Tx/Rx connections on the Arduino before uploading a program which I did not do when following the first tutorial (it wasn’t mentioned there.) I don’t know if that can damage the transceiver modules, but it doesn’t seem like it would.

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