mkr 1300, the things network and mydevices cayenne

Projects Programming
9

To my opinion -aside of the issue with sending data too frequently- is that your code obviously refers to The Things Uno device based on the TheThingsNetwork library <TheThingsNetwork.h>. This library however requires the use of a LoRa Module controlled via a UART. TheThingsUno uses an Arduino Leonardo that controls the RN2483 Lora Module via the Serial1 UART interface. The Arduino MKR WAN however uses an CMWX1ZZABZ LoRa Module that is controlled via a SPI interface which is handled inside the <MKRWAN.h> library. Therefore, you need to use the <MKRWAN.h> library together with Cayenne. This means, instead of sending the data with :

ttn.sendBytes(lpp.getBuffer(), lpp.getSize());

you have to use the following call from the MKRWAN library:

modem.write(lpp.getBuffer(), lpp.getSize());

A working code example derived from the MKRWAN Library Send and Receive Example is the following:

/*
  Lora Send And Receive
  This sketch demonstrates how to send and receive data with the MKR WAN 1300 LoRa module.
  This example code is in the public domain.
*/

#include <MKRWAN.h>
#include <CayenneLPP.h>

LoRaModem modem;
CayenneLPP lpp(51);

// Uncomment if using the Murata chip as a module
// LoRaModem modem(Serial1);

//#include "arduino_secrets.h"
// Please enter your sensitive data in the Secret tab or arduino_secrets.h
String appEui = " *** ";
String appKey = " *** ";

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  
  pinMode(LED_BUILTIN, OUTPUT);        //sign of live
  for (int i=1; i<=10; i++) {           
    digitalWrite(LED_BUILTIN, HIGH);   // turn the LED on (HIGH is the voltage level)
    delay(1000);                       // wait for a second
    digitalWrite(LED_BUILTIN, LOW);    // turn the LED off by making the voltage LOW
    delay(1000);
    // wait for a second
    Serial.println(10-i);
  }
  
  // change this to your regional band (eg. US915, AS923, ...)
  if (!modem.begin(EU868)) {
    Serial.println("Failed to start module");
    while (1) {}
  };
  Serial.print("Your module version is: ");
  Serial.println(modem.version());
  Serial.print("Your device EUI is: ");
  Serial.println(modem.deviceEUI());

  int connected = modem.joinOTAA(appEui, appKey);
  if (!connected) {
    Serial.println("Something went wrong; are you indoor? Move near a window and retry");
    while (1) {}
  }

  // Set poll interval to 60 secs.
  modem.minPollInterval(60);
  // NOTE: independently by this setting the modem will
  // not allow to send more than one message every 2 minutes,
  // this is enforced by firmware and can not be changed.
}

void loop() {
  int err;
  
  lpp.reset();
  lpp.addTemperature(1, 22.5);
  modem.beginPacket();
  modem.write(lpp.getBuffer(), lpp.getSize());
  err = modem.endPacket(true);
  if (err > 0) {
    Serial.println("Message sent correctly!");
  } else {
    Serial.println("Error sending message :(");
    Serial.println("(you may send a limited amount of messages per minute, depending on the signal strength");
    Serial.println("it may vary from 1 message every couple of seconds to 1 message every minute)");
  }
  delay(1000);
  if (!modem.available()) {
    Serial.println("No downlink message received at this time.");
  }
  else {
    String rcv;
    rcv.reserve(64);
    while (modem.available()) {
      rcv += (char)modem.read();
    }
    Serial.print("Received: " + rcv + " - ");
    for (unsigned int i = 0; i < rcv.length(); i++) {
      Serial.print(rcv[i] >> 4, HEX);
      Serial.print(rcv[i] & 0xF, HEX);
      Serial.print(" ");
    }
    Serial.println();
  }
  Serial.println("waiting 60 seconds");
  for (int i=1; i<=60; i++) { //wait a minute
    Serial.println(i);
    delay(1000); 
  }  
}