Answering one of my own questions.
On ethernet gateway send() may return true when there is no connected controller, even when there is no ethernet cable plugged in. :/

@matkor said in How ethernet gateway code can check if is connected with controller?:

1. Is any way to know if controller is connected ?
2. Is any way to know if send message really reached controller?

Seems positive send() result means message reached controller when executed on gateway?

Having arduino ethernet gateway I need to send messages with senors values to controller (Home assistant requirement to auto configure sensors).
With serial gateway simple sending in first iteration of loop:

	void loop() {
		if ( ! inital_msgs_sent ) {
			inputs.sendStates(); 
			outputs.sendStates();
			inital_msgs_sent = true;

worked.

But with ethernet controller loop starts when HA is not yet connected to GW so sent messages do not reach controller :/
So, how should I fix it?

1. Is any way to know if controller is connected ?
2. Is any way to know if controller requested presentation?
3. Is any way to know if send message really reached controller?

TIA, regards,

@matkor said in How can one use MyMessage class in library?:

Switching both clashing functions ( wakeUp1(), wakeUp2() ) to static functions seems to fix linking for me.

This sees to be deadend as there come more function name clashes, and i suspect linking problems come from magic done by arduino IDE.

Current hack for me is include in arduino sketch my lib headers after including MySensors:

#include <MySensors.h>
#include <MyLib.h>

and than inside library use only:

#include <core/MySensorsCore.h>

not sure if its right solution, if one has any better please share.

Switching both clashing functions ( wakeUp1(), wakeUp2() ) to static functions seems to fix linking for me.

diff --git a/hal/architecture/AVR/MyHwAVR.cpp b/hal/architecture/AVR/MyHwAVR.cpp
index 5a17b063..a018ab35 100644
--- a/hal/architecture/AVR/MyHwAVR.cpp
+++ b/hal/architecture/AVR/MyHwAVR.cpp
@@ -41,7 +41,7 @@ volatile uint8_t _wakeUp2Interrupt  =
 
 static uint32_t sleepRemainingMs = 0ul;
 
-void wakeUp1(void)
+void static wakeUp1(void)
 {
        // Disable sleep. When an interrupt occurs after attachInterrupt,
        // but before sleeping the CPU would not wake up.
@@ -53,7 +53,7 @@ void wakeUp1(void)
                _wokeUpByInterrupt = _wakeUp1Interrupt;
        }
 }
-void wakeUp2(void)
+void static wakeUp2(void)
 {
        sleep_disable();
        detachInterrupt(_wakeUp2Interrupt);
diff --git a/hal/architecture/NRF5/MyHwNRF5.cpp b/hal/architecture/NRF5/MyHwNRF5.cpp
index d91a0438..f083a17c 100644
--- a/hal/architecture/NRF5/MyHwNRF5.cpp
+++ b/hal/architecture/NRF5/MyHwNRF5.cpp
@@ -28,11 +28,11 @@ volatile uint8_t _wakeUp1Interrupt =
 volatile uint8_t _wakeUp2Interrupt =
     INVALID_INTERRUPT_NUM; // Interrupt number for wakeUp2-callback.
 
-void wakeUp1(void) // place to send the interrupts
+void static wakeUp1(void) // place to send the interrupts
 {
        _wokeUpByInterrupt = _wakeUp1Interrupt;
 }
-void wakeUp2(void) // place to send the second interrupts
+void static wakeUp2(void) // place to send the second interrupts
 {
        _wokeUpByInterrupt = _wakeUp2Interrupt;
 }

@tekka said in How can one use MyMessage class in library?:

#define MY_CORE_ONLY

It solved compiiation errors, but now I have link errors(I have many .cpp/.h files in my lib):

/tmp/arduino_build_899057/libraries/MyLib/Foo.cpp.o (symbol from plugin): In function `wakeUp1()':(.text+0x0): multiple definition of `wakeUp1()'

Seems same as https://forum.mysensors.org/topic/6084/including-mysensors-h-in-multiple-files .
I tried:

#include <core/MySensorsCore.h>

but it fails:

Alternatives for core/MyMessage.h: []In file included from mytest.ino:13:0:
ResolveLibrary(core/MyMessage.h)
  -> candidates: []

MyLib/MyLib.h:10:10: fatal error: core/MyMessage.h: No such file or directory
 #include <core/MyMessage.h>
          ^~~~~~~~~~~~~~~~~~
compilation terminated.

How can one use MyMessage class in library?

When I try to

#include <MySensors.h>

in my library code I get:
Arduino/libraries/MySensors/MySensors.h:426:2: error: #error No forward link or gateway feature activated. This means nowhere to send messages! Pretty pointless.

without include I of course get:

Button.h:13:5: error: 'MyMessage' does not name a type
MyMessage msg;

@mfalkvidd

Use the W5100 module instead (if you need ethernet)

Good idea, thanks! Same code, but only W5100 based:
Sketch uses 17190 bytes (...) Global variables use 853 bytes (41%)

Using W5500 ( Ethernet2.h ) gives even better:
Sketch uses 14712 bytes (...) Global variables use 809 bytes (39%)

If you don’t need ethernet, use usb or wifi since those options also use less ram.

I need some kind of 25m wire so options are ethernet, RS-485 or PJON

I need only few binary sensors/switches (relays) controllable from HomeAssistant, so I hoped to add their simple logic to
https://github.com/mysensors/MySensorsArduinoExamples/blob/master/examples/GatewayENC28J60/GatewayENC28J60.ino
But building above already takes: Sketch uses 29276 bytes (...) Global variables use 1757 bytes

I tried to reduce SRAM usage, but disabling MY_DEBUG, MY_RADIO_RF24, MY_INCLUSION_* , MY_DEFAULT_* reduces sizes to
Sketch uses 22980 bytes (...) Global variables use 1626 bytes (79%)
only :(

Is there any way one can go down with SRAM usage further?

Assuming I have light switch/push button with only readable state (via pin on Arduino).
Following https://www.mysensors.org/download/serial_api_20#sensor-types ,should I present it via:

present(CHILD_ID, S_BINARY);

?

Later, having binary switch (which should be settable from controller) how it should be presented?

How controller can distinguish between RO button and RW switch?