Thank you very much!
I was very upset when I realized that such titanic work and useful information would be lost..

Hello, friend!
May be you need addition send in loop for HA, look at Presentaion

Hello, friend.
Do you read this Presentation?

Hi, friend!
He also became interested in the Home Assistant system, but was upset by the lack of support OTA.
I use a system Majordomo for MySensors devices and my Ethernet-RS485 gateways are based on ENC28J60.
And I found such an idea for myself - to implement a proxy for the TCP protocol in order to implement a parallel connection to the gateway of two systems at the same time.
I tested this solution and it turned out to work - I was able to flash via OTA , while simultaneously receiving data in Home Assistant.
Perhaps this idea will be of interest to you.

@hypnosiss you may be interested in this https://forum.mysensors.org/topic/11814/rs485-transport-ack-support/6

@gieemek Great thanks for you solution, it's work perfect!!
I just change the timeout for resend message to 250ms.
Using now in 6 my RS485 nodes.

@gieemek thanks, this is a good idea! I was thinking about something similar..

@gieemek Can you explain how do you using ACK on RS485? in my practice i see, that having no error, but lossing packets..
I mean that what construction don't working correctly:

boolean MYS_send(MyMessage Msg) {
  boolean status = false;
  int counter = 3;
  
  do {
    status = send(Msg);
    if (status)
    {
      SendCount++;
      return status;
    }
  else
    {
      SendError++;
      counter--;
      wait(50);      
    }
  } while (counter > 0);

  return status;
}

@nexus1212 Hello frend. I am using 0xE2 0xDA 0x06 for my atmega 8Mhz.

@vdomos it is possible to connect the ground wire of the RS485 adapters?

@vdomos this is very strange - it works for me without this directive..

#define MY_BAUD_RATE 9600
#define MY_NODE_ID 111
//#define MY_PARENT_NODE_ID 0
//#define MY_PARENT_NODE_IS_STATIC

#define MY_DEBUG

#define MY_OTA_FIRMWARE_FEATURE
#define MY_OTA_FLASH_SS 16  //  pin A2 of Arduino Pro Mini
#define MY_OTA_FLASH_JDECID 0xEF30

#define MY_OTA_RETRY (10u)
#define MY_OTA_RETRY_DELAY (2000u)

#define MY_RS485
#define MY_RS485_DE_PIN 7
#define MY_RS485_BAUD_RATE 9600

#include <SPI.h>
#include <MySensors.h>

void setup()
{
  pinMode(6, OUTPUT);
}

void before() { 
}

void presentation()
{
  sendSketchInfo("Test_RS485_OTA", "2.3.2.0.004");
}

void loop()
{
  digitalWrite(6,0);
  wait(100);
  digitalWrite(6,1);
  wait(100);
  digitalWrite(6,0);
  wait(100);
  digitalWrite(6,1);

  sendHeartbeat();
  wait(5000);
}

I want to share an interesting case about updating the firmware over FOTA..

I have several nodes on a RS485 bus with memory chips.
Recently I decided to update the firmware on several at once and ran into an unexpected problem - repeated attempts to update constantly ended up with a checksum error !OTA:FWP:CRC FAIL.

At the same time, I usually test all new nodes for FOTA firmware updates before installing.

I tried to understand what the problem might be and came to an unexpected result - in my case, disabling the directive OTA_EXTRA_FLASH_DEBUG, which I had been using for a long time, when I first tested updates, helped.

After disabling this directive, all firmwares were updated the first time. Very strange, but nevertheless ...

@gryzli133 I have a number of MySensors devices using RS485, it would be interesting to try to run PJON protocol over RS485, it seems like there is such an opportunity, but I could not figure out how to use it in the MySensors library.

like this

send(msgPir.setSensor(Number).set(State?"1":"0"));

@Flyer Do you can ping the gateway on it IP?

@skywatch May be you right - the distance between node and gateway so small..
But how can i solve the problem of unstable link with node on distance about 5m and more with wall between node and gateway?

@skywatch Yes, FOTA works with both modules, it is one gateway, i just change one module (black) to another (Ebyte), distance between gatway and node aprox 2-3m.
I want to find a solution to increase distance, because of some of my node work unstable..

@skywatch The peoblem is in not working OTA with NRF24-PA-LNA, if the RF24_PA_LEVEL parameter has not the RF24_PA_LOW value..
It's refers to Ebyte module too..
The power supply is the brand Samsung power adapter for the tablet and the LM1117 3.3V with 100uF capacitor.

@skywatch I am using this module

and like this