@mfalkvidd said:

@gvorster 868 is the default so you don't need to do anything. If you want to change it, add

#define MY_RFM69_FREQUENCY

Great, thanks!

@gloob said:

How are the leds connected to the arduino? Are the LEDs connected to ground or 5V?

Ah, sorry my bad. That's it. I had it turned around.
Should have rtfm:

"Each LED is connected by its anode (long leg) to +5V. The cathode (short leg) is connected through a resistor to one of the following digital pins of the Arduino:"

@mfalkvidd said in 💬 Serial Protocol - 2.x:

@gvorster see https://forum.mysensors.org/post/43373

Thanks, got it now.

@siod said in 💬 Serial Protocol - 2.x:

@gvorster Thank you for explanation!

One more thing: I wanted to implement a sendHeartbeat() into a Repeater node (which should never sleep!), where should I put this function and how? When putting it just into the loop it is of course spamming my gateway with heartbeat messages...Is it possible anyway?

There are many examples code how to do this. One Timer library I use myself is this https://playground.arduino.cc/Code/Timer

e.g. for a repeater you could use this:

#include "Timer.h"

Timer t;

void setup() {
    t.every(60000, sendImAlive);
}

void loop() {
    t.update();
}

void sendImAlive() {
    sendHeartbeat();
}