@mfalkvidd Yeah, it became stable after I did the same. I will have to simplify the tasks for my bare bones nodes.
Since I'm getting wrong (no warnings) memory messages uploading, do you think I should edit boards.txt?

atmega328bb.name=ATmega328 on a breadboard (8 MHz internal clock)

atmega328bb.upload.protocol=arduino
atmega328bb.upload.maximum_size=30720
atmega328bb.upload.speed=57600

atmega328bb.bootloader.low_fuses=0xE2
atmega328bb.bootloader.high_fuses=0xDA
atmega328bb.bootloader.extended_fuses=0xfd

atmega328bb.bootloader.file=atmega/ATmegaBOOT_168_atmega328_pro_8MHz.hex
atmega328bb.bootloader.unlock_bits=0x3F
atmega328bb.bootloader.lock_bits=0x0F

atmega328bb.build.mcu=atmega328p
atmega328bb.build.f_cpu=8000000L
atmega328bb.build.core=arduino:arduino
atmega328bb.build.variant=arduino:standard


atmega328bb.bootloader.tool=arduino:avrdude
atmega328bb.upload.tool=arduino:avrdude```

I finally got bootloader and upload issues done, but now one sketch/node is killing me. I have tried different AtMega328Ps but the symptom remains.
The node: SlimNode, constant power (step down to 3.3V from alarm system 12V battery), non-PA NRF24, DHT11. Extra LED to blink at start-up, extra cap 100yF at power input. Pins/connections verified once extra.

Serial:

 __  __       ____
|  \/  |_   _/ ___|  ___ _ __  ___  ___  _ __ ___
| |\/| | | | \___ \ / _ \ `_ \/ __|/ _ \| `__/ __|
| |  | | |_| |___| |  __/ | | \__ \  _  | |  \__ \
|_|  |_|\__, |____/ \___|_| |_|___/\___/|_|  |___/
        |___/                      2.3.1

34 MCO:BGN:INIT REPEATER,CP=RNNRASQ-,REL=255,VER=2.3.1
55 MCO:BGN:BFR
2093 TSM:INIT
2097 TSF:WUR:MS=0
2105 TSM:INIT:TSP OK
2109 TSM:INIT:STATID=3
2113 TSF:SID:OK,ID=3
2117 TSM:FPAR
2154 TSF:MSG:SEND,3-3-255-255,s=255,c=3,t=7,pt=0,l=0,sg=0,ft=0,st=OK:
3115 TSF:MSG:READ,0-0-3,s=255,c=3,t=8,pt=1,l=1,sg=0:0
3125 TSF:MSG:FPAR OK,ID=0,D=1
4167 TSM:FPAR:OK
4169 TSM:ID
4171 TSM:ID:OK
4175 TSM:UPL
4182 TSF:MSG:SEND,3-3-0-0,s=255,c=3,t=24,pt=1,l=1,sg=0,ft=0,st=OK:1
4194 TSF:MSG:READ,0-0-3,s=255,c=3,t=25,pt=1,l=1,sg=0:1
4204 TSF:MSG:PONG RECV,HP=1
4208 TSM:UPL:OK
4212 TSM:READY:ID=3,PAR=0,DIS=1
4222 TSF:MSG:SEND,3-3-0-0,s=255,c=3,t=15,pt=6,l=2,sg=0,ft=0,st=OK:0101
4235 TSF:MSG:READ,0-0-3,s=255,c=3,t=15,pt=6,l=2,sg=0:0101
4249 TSF:MSG:SEND,3-3-0-0,s=255,c=3,t=16,pt=0,l=0,sg=0,ft=0,st=OK:
4263 TSF:MSG:READ,0-0-3,s=255,c=3,t=17,pt=6,l=25,sg=0:<NONCE>
4329 TSF:MSG:SEND,3-3-0-0,s=255,c=0,t=18,pt=0,l=5,sg=1,ft=1,st=OK:2.3.1
4341 !TSF:RTE:FPAR ACTIVE
 
 __  __       ____
|  \/  |_   _/ ___|  ___ _ __  ___  ___  _ __ ___
| |\/| | | | \___ \ / _ \ `_ \/ __|/ _ \| `__/ __|
| |  | | |_| |___| |  __/ | | \__ \  _  | |  \__ \
|_|  |_|\__, |____/ \___|_| |_|___/\___/|_|  |___/
        |___/                      2.3.1

36 MCO:BGN:INIT REPEATER,CP=RNNRASQ-,REL=255,VER=2.3.1
57 MCO:BGN:BFR

...and this keeps repeating

Code:

/**
 *
 * DESCRIPTION
 * Temp Sensor and repeater / Slim node
 *
 */

#define MY_DEBUG
#define MY_RADIO_RF24
#define MY_REPEATER_FEATURE   // Enable repeater functionality for this node
#define MY_SIGNING_SIMPLE_PASSWD "XXXXXXXXXX"
#define MY_RF24_IRQ_PIN 2
#define MY_RX_MESSAGE_BUFFER_FEATURE
#define MY_NODE_ID 3
#define MY_BAUD_RATE 57600

#define DHT_DATA_PIN 4
#define SENSOR_TEMP_OFFSET 0
#define HUM 1
#define TEMP 2

static const uint8_t FORCE_UPDATE_N_READS = 10;
float lastTemp;
float lastHum;
uint8_t nNoUpdatesTemp;
uint8_t nNoUpdatesHum;
bool metric = true;

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

MyMessage msgHum(HUM, V_HUM);
MyMessage msgTemp(TEMP, V_TEMP);
DHT dht;

void before()
{
  pinMode(7, OUTPUT);
  int i = 0;
  for(i=0; i < 5; i++) {
    digitalWrite(7, HIGH);
    delay(100);
    digitalWrite(7, LOW);
    delay(300);
}
}

void setup()
{
  delay(100);  // Let power settle
  dht.setup(DHT_DATA_PIN); // set data pin of DHT sensor
  wait(2000);
}

void presentation()  
{ 
  sendSketchInfo("Temp Sensor & Repeater", "v06012019");
  present(HUM, S_HUM);
  present(TEMP, S_TEMP);
  metric = getControllerConfig().isMetric;
}

void loop()
{
   // Force reading sensor, so it works also after sleep()
  dht.readSensor(true);
  float temperature = dht.getTemperature();
  if (isnan(temperature)) {
    Serial.println("Failed reading temperature from DHT!");
  } else if (temperature != lastTemp || nNoUpdatesTemp == FORCE_UPDATE_N_READS) {
    // Only send temperature if it changed since the last measurement or if we didn't send an update for n times
    lastTemp = temperature;
    if (!metric) {
      temperature = dht.toFahrenheit(temperature);
    }
    // Reset no updates counter
    nNoUpdatesTemp = 0;
    temperature += SENSOR_TEMP_OFFSET;
    send(msgTemp.set(temperature, 1));

    #ifdef MY_DEBUG
    Serial.print("T: ");
    Serial.println(temperature);
    #endif
  } else {
    // Increase no update counter if the temperature stayed the same
    nNoUpdatesTemp++;
  }

  float humidity = dht.getHumidity();
  if (isnan(humidity)) {
    Serial.println("Failed reading humidity from DHT");
  } else if (humidity != lastHum || nNoUpdatesHum == FORCE_UPDATE_N_READS) {
    // Only send humidity if it changed since the last measurement or if we didn't send an update for n times
    lastHum = humidity;
    // Reset no updates counter
    nNoUpdatesHum = 0;
    send(msgHum.set(humidity, 1));

    #ifdef MY_DEBUG
    Serial.print("H: ");
    Serial.println(humidity);
    #endif
  } else {
    // Increase no update counter if the humidity stayed the same
    nNoUpdatesHum++;
  }

  // Sleep for a while to save energy
  //sleep(UPDATE_INTERVAL); 
//}
wait(120000);
}

I dont think it's a power issue but what else could it be? Behavior is the same with DHT11 unplugged. Also same if powering from FTDI.

Can someone help me with these questions?
I want the Slim Node to function "like a 3.3/8mhz pro mini" for MySensors home autom applications. So I can upload sketches thru ftdi-pins. Since I also use Pro Minis, I would not want change the mysensors library (serial baud).

1. if I load the bootloader with a 8mhz crystal on the breadboard, does my barebones Slim node need a crystal too?
2. If I set serial.begin in the sketch, does it override the MySensors default? So I could have that for slim node sketches.
3. What kind of nodes would be problematic without crystal use? Repeater?
4. Is it possible to Uno+breadboard just bootload all atmega328p's and then just solder onto SlimNode and use ftdi for uploading sketches (as I would normally to a Pro Mini)? In other words do I have to rethink the whole thing.

I have now. I always have that nagging feeling...
But after MANY iterations, finally success. At least partly.

BlinkWithoutDelay works AND mysensors sketch as well (will do more testing...).
What made it work, if anyone else struggles with this:

-connect uno (to computer-linux), board:uno, upload ArduinoISP, disconnect
-add shield to uno and atmega328p-pu to shield, connect to computer, board: "8mhz on breadboard", "programmer: "Arduino as ISP", burn bootloader, disconnect
-board: Uno, connect as above, "upload sketch using programmer", disconnect EDIT this last part appears to work but internal clock is all messed up. Bootloader works fine like this.

The magic happened after I changed the board back to Uno after burning bootloader. Why is beyond me, but maybe some arduino-ninja can figure it out.

@electrik Everything's 100% chinese
I checked power at all terminals and the atmega-connections, as well as radio hookup etc. I have all the caps on "My Slim Node" (4x 0,1yF and 4,7 yF). I normally get better power thru regulators than with FTDI but I did check that originally.

I built two like this, same type of problem. I have Gert Sanders's "boards" installed. Is there a very basic setup I could try? I'm having trouble figuring out all the options that are available. All I want is Atmega working like a normal 3.3v/8MHz Arduino.

Continuing on...I need help getting my Atmega328P-PU to work.

I'm able to burn the bootloader (8MHz on breadboard) and upload sketch ("using programmer"). However when I power the PCB, the sketch doesn't run. I soldered on a LED and uploaded BlinkWithoutDelay, just to verify that it works, but does not. I measured power and all connections. I'm powering with regulated 3.3V.

To make things more weird, I connected FTDI to one node and with that connection it works fine. But when powering from pins, nothing (again using regulated 3.3V.

@nagelc I've been afraid to try that. Maybe do a full backup and try it. Not sure if I should erase everything first or not.

I'm having trouble updating and can't find answer just googling it.
My dashboard shows v3.7243.

It's running on a linux machine. I've tried the .updaterelease but it terminates because it doesn't seem to locate a network address. If I click in the dashboard window (setup - check for update) it says "no update available".

I haven't logged on to Domoticz forum (yet), to ask around there if someone here can help. I did try to google for help but found nothing useful.

@timo OK, here's the output:

2018-08-15 23:55:44.092 [INFO ] [.transport.mqtt.MqttBrokerConnection] - Starting MQTT broker connection to '127.0.0.1' with clientid paho79389486520739 and file store '/var/lib/openhab2/mqtt/127.0.0.1'

2018-08-15 23:55:47.333 [INFO ] [er.internal.HomeBuilderDashboardTile] - Started Home Builder at /homebuilder

2018-08-15 23:55:53.357 [INFO ] [.core.internal.i18n.I18nProviderImpl] - Time zone set to 'Europe/Helsinki'.

2018-08-15 23:55:53.406 [INFO ] [.core.internal.i18n.I18nProviderImpl] - Location set to '60.172424790463936,25.020736667463083'.

2018-08-15 23:55:53.427 [INFO ] [.core.internal.i18n.I18nProviderImpl] - Locale set to 'fi'.

2018-08-15 23:56:01.971 [INFO ] [.dashboard.internal.DashboardService] - Started Dashboard at http://192.168.1.51:8080

2018-08-15 23:56:02.082 [INFO ] [.dashboard.internal.DashboardService] - Started Dashboard at https://192.168.1.51:8443

2018-08-15 23:57:01.390 [INFO ] [el.core.internal.ModelRepositoryImpl] - Loading model 'default.items'

2018-08-15 23:57:21.507 [INFO ] [thome.model.lsp.internal.ModelServer] - Started Language Server Protocol (LSP) service on port 5007

2018-08-15 23:57:24.448 [INFO ] [el.core.internal.ModelRepositoryImpl] - Loading model 'default.sitemap'

2018-08-15 23:57:26.351 [INFO ] [el.core.internal.ModelRepositoryImpl] - Loading model 'mys.things'

==> /var/log/openhab2/events.log <==

2018-08-15 23:57:27.306 [.ItemChannelLinkAddedEvent] - Link 'PukuhLiike-mysensors:motion:mygateway1:PukuhLiike:tripped' has been added.

2018-08-15 23:57:27.346 [.ItemChannelLinkAddedEvent] - Link 'PukuhValoisuus-mysensors:light-level:mygateway1:PukuhValoisuus:light-level' has been added.

2018-08-15 23:57:27.424 [.ItemChannelLinkAddedEvent] - Link 'TalliSivuoviLukko-mysensors:lock:mygateway1:TalliSivuoviLukko:lock-status' has been added.

2018-08-15 23:57:27.487 [.ItemChannelLinkAddedEvent] - Link 'BoilerTemp-mysensors:temperature:mygateway1:BoilerTemp:temp' has been added.

2018-08-15 23:57:27.655 [.ItemChannelLinkAddedEvent] - Link 'TalliSivuovi-mysensors:door:mygateway1:TalliSivuovi:tripped' has been added.

==> /var/log/openhab2/openhab.log <==

2018-08-15 23:57:44.601 [DEBUG] [org.openhab.binding.mysensors       ] - BundleEvent STARTING - org.openhab.binding.mysensors

2018-08-15 23:57:46.005 [DEBUG] [org.openhab.binding.mysensors       ] - ServiceEvent REGISTERED - {org.eclipse.smarthome.core.thing.binding.ThingHandlerFactory}={service.id=296, service.bundleid=197, service.scope=bundle, component.name=org.openhab.binding.mysensors.factory.MySensorsHandlerFactory, component.id=176} - org.openhab.binding.mysensors

2018-08-15 23:57:47.811 [DEBUG] [org.openhab.binding.mysensors       ] - BundleEvent STARTED - org.openhab.binding.mysensors

2018-08-15 23:57:53.081 [INFO ] [basic.internal.servlet.WebAppServlet] - Started Basic UI at /basicui/app

2018-08-15 23:57:56.733 [INFO ] [arthome.ui.paper.internal.PaperUIApp] - Started Paper UI at /paperui

2018-08-15 23:57:59.038 [INFO ] [panel.internal.HABPanelDashboardTile] - Started HABPanel at /habpanel

2018-08-15 23:58:02.474 [DEBUG] [nsors.handler.MySensorsBridgeHandler] - Initialization of the MySensors bridge

==> /var/log/openhab2/events.log <==

2018-08-15 23:58:02.518 [hingStatusInfoChangedEvent] - 'mysensors:bridge-mqtt:mygateway1' changed from UNINITIALIZED to INITIALIZING

==> /var/log/openhab2/openhab.log <==

2018-08-15 23:58:02.740 [DEBUG] [ensors.factory.MySensorsCacheFactory] - Cache file: given_ids.cached exist.

2018-08-15 23:58:02.777 [DEBUG] [ensors.factory.MySensorsCacheFactory] - Cache (given_ids) content: [1]

2018-08-15 23:58:03.074 [DEBUG] [rotocol.mqtt.MySensorsMqttConnection] - Enabling connection watchdog

2018-08-15 23:58:03.246 [DEBUG] [rotocol.mqtt.MySensorsMqttConnection] - Connected to MQTT broker!

2018-08-15 23:58:03.294 [DEBUG] [org.openhab.binding.mysensors       ] - ServiceEvent REGISTERED - {org.eclipse.smarthome.config.discovery.DiscoveryService}={service.id=324, service.bundleid=197, service.scope=singleton} - org.openhab.binding.mysensors

2018-08-15 23:58:03.308 [DEBUG] [.discovery.MySensorsDiscoveryService] - Starting MySensors discovery scan

2018-08-15 23:58:03.330 [DEBUG] [nsors.handler.MySensorsBridgeHandler] - Initialization of the MySensors bridge DONE!

==> /var/log/openhab2/events.log <==

2018-08-15 23:58:03.493 [hingStatusInfoChangedEvent] - 'mysensors:temperature:mygateway1:BoilerTemp' changed from UNINITIALIZED to UNINITIALIZED (BRIDGE_UNINITIALIZED)

2018-08-15 23:58:03.617 [hingStatusInfoChangedEvent] - 'mysensors:motion:mygateway1:PukuhLiike' changed from UNINITIALIZED to UNINITIALIZED (BRIDGE_UNINITIALIZED)

==> /var/log/openhab2/openhab.log <==

2018-08-15 23:58:03.743 [DEBUG] [rotocol.mqtt.MySensorsMqttConnection] - Adding consumer for topic: mysensors-out/+/+/+/+/+

==> /var/log/openhab2/events.log <==

2018-08-15 23:58:03.840 [hingStatusInfoChangedEvent] - 'mysensors:light-level:mygateway1:PukuhValoisuus' changed from UNINITIALIZED to UNINITIALIZED (BRIDGE_UNINITIALIZED)

2018-08-15 23:58:03.908 [hingStatusInfoChangedEvent] - 'mysensors:door:mygateway1:TalliSivuovi' changed from UNINITIALIZED to UNINITIALIZED (BRIDGE_UNINITIALIZED)

2018-08-15 23:58:03.997 [hingStatusInfoChangedEvent] - 'mysensors:lock:mygateway1:TalliSivuoviLukko' changed from UNINITIALIZED to UNINITIALIZED (BRIDGE_UNINITIALIZED)

==> /var/log/openhab2/openhab.log <==

2018-08-15 23:58:04.055 [DEBUG] [rsAbstractConnection$MySensorsWriter] - Sending to MySensors: 0;0;3;0;2;

2018-08-15 23:58:04.076 [DEBUG] [rotocol.mqtt.MySensorsMqttConnection] - Sending MQTT Message: Topic: mysensors-in, Message: 0;0;3;0;2;

2018-08-15 23:58:04.241 [DEBUG] [rotocol.mqtt.MySensorsMqttConnection] - MQTT message received. Topic: mysensors-out/0/255/3/0/2, Message: 2.3.0

2018-08-15 23:58:04.276 [DEBUG] [rotocol.mqtt.MySensorsMqttConnection] - Message topic part: 0/255/3/0/2

2018-08-15 23:58:04.311 [DEBUG] [rotocol.mqtt.MySensorsMqttConnection] - Converted MQTT message to MySensors Serial format. Sending on to bridge: 0;255;3;0;2;2.3.0

2018-08-15 23:58:04.373 [DEBUG] [rsAbstractConnection$MySensorsReader] - Message from gateway received: 0;255;3;0;2;2.3.0

2018-08-15 23:58:04.390 [DEBUG] [rsAbstractConnection$MySensorsReader] - Good,Gateway is up and running! (Ver:2.3.0)

==> /var/log/openhab2/events.log <==

2018-08-15 23:58:04.849 [hingStatusInfoChangedEvent] - 'mysensors:bridge-mqtt:mygateway1' changed from INITIALIZING to ONLINE

==> /var/log/openhab2/openhab.log <==

2018-08-15 23:58:04.940 [DEBUG] [ensors.factory.MySensorsCacheFactory] - Writing on cache given_ids, content: [1]

2018-08-15 23:58:04.975 [INFO ] [rotocol.mqtt.MySensorsMqttConnection] - Successfully connected to MySensors Bridge.

2018-08-15 23:58:05.191 [DEBUG] [ensors.handler.MySensorsThingHandler] - Configuration: MySensorsSensorConfiguration{nodeId=5, childId=5, requestAck=false, revertState=true, smartSleep=false, childUpdateTimeout=-1, nodeUpdateTimeout=-1, requestHeartbeatResponse=false, usePureWhiteLightInRGBW=false}

==> /var/log/openhab2/events.log <==

2018-08-15 23:58:05.211 [hingStatusInfoChangedEvent] - 'mysensors:temperature:mygateway1:BoilerTemp' changed from UNINITIALIZED (BRIDGE_UNINITIALIZED) to INITIALIZING

==> /var/log/openhab2/openhab.log <==

2018-08-15 23:58:05.224 [DEBUG] [ensors.handler.MySensorsThingHandler] - Configuration: MySensorsSensorConfiguration{nodeId=1, childId=15, requestAck=false, revertState=true, smartSleep=false, childUpdateTimeout=-1, nodeUpdateTimeout=-1, requestHeartbeatResponse=false, usePureWhiteLightInRGBW=false}

2018-08-15 23:58:05.347 [DEBUG] [ensors.handler.MySensorsThingHandler] - Configuration: MySensorsSensorConfiguration{nodeId=1, childId=3, requestAck=false, revertState=true, smartSleep=false, childUpdateTimeout=-1, nodeUpdateTimeout=-1, requestHeartbeatResponse=false, usePureWhiteLightInRGBW=false}

2018-08-15 23:58:05.404 [DEBUG] [ensors.handler.MySensorsThingHandler] - Configuration: MySensorsSensorConfiguration{nodeId=1, childId=14, requestAck=false, revertState=true, smartSleep=false, childUpdateTimeout=-1, nodeUpdateTimeout=-1, requestHeartbeatResponse=false, usePureWhiteLightInRGBW=false}

2018-08-15 23:58:05.494 [DEBUG] [ensors.handler.MySensorsThingHandler] - Configuration: MySensorsSensorConfiguration{nodeId=5, childId=6, requestAck=false, revertState=true, smartSleep=false, childUpdateTimeout=-1, nodeUpdateTimeout=-1, requestHeartbeatResponse=false, usePureWhiteLightInRGBW=false}

2018-08-15 23:58:05.521 [DEBUG] [rs.internal.gateway.MySensorsGateway] - Adding device MySensorsNode [nodeId=5, childNumber=1, chidldList={5=MySensorsChild [childId=5, nodeValue={V_VAR1=MySensorsVariableVVar1 [value=null], V_VAR2=MySensorsVariableVVar2 [value=null], V_VAR3=MySensorsVariableVVar3 [value=null], V_LOCK_STATUS=MySensorsVariableVLockStatus [value=null], V_VAR4=MySensorsVariableVVar4 [value=null], V_VAR5=MySensorsVariableVVar5 [value=null]}]}]

2018-08-15 23:58:05.610 [DEBUG] [rs.internal.gateway.MySensorsGateway] - Merging child map: {5=MySensorsChild [childId=5, nodeValue={V_VAR1=MySensorsVariableVVar1 [value=null], V_VAR2=MySensorsVariableVVar2 [value=null], V_VAR3=MySensorsVariableVVar3 [value=null], V_LOCK_STATUS=MySensorsVariableVLockStatus [value=null], V_VAR4=MySensorsVariableVVar4 [value=null], V_VAR5=MySensorsVariableVVar5 [value=null]}]} with: {6=MySensorsChild [childId=6, nodeValue={V_VAR1=MySensorsVariableVVar1 [value=null], V_TRIPPED=MySensorsVariableVTripped [value=null], V_ARMED=MySensorsVariableVArmed [value=null], V_VAR2=MySensorsVariableVVar2 [value=null], V_VAR3=MySensorsVariableVVar3 [value=null], V_VAR4=MySensorsVariableVVar4 [value=null], V_VAR5=MySensorsVariableVVar5 [value=null]}]}

2018-08-15 23:58:05.607 [DEBUG] [ensors.handler.MySensorsThingHandler] - Event listener for node 5-5 not registered yet, registering...

==> /var/log/openhab2/events.log <==

2018-08-15 23:58:05.704 [hingStatusInfoChangedEvent] - 'mysensors:lock:mygateway1:TalliSivuoviLukko' changed from UNINITIALIZED (BRIDGE_UNINITIALIZED) to INITIALIZING

==> /var/log/openhab2/openhab.log <==

2018-08-15 23:58:05.737 [DEBUG] [rs.internal.gateway.MySensorsGateway] - Merging child map: {} with: {14=MySensorsChild [childId=14, nodeValue={V_VAR1=MySensorsVariableVVar1 [value=null], V_LEVEL=MySensorsVariableVLevel [value=null], V_VAR2=MySensorsVariableVVar2 [value=null], V_VAR3=MySensorsVariableVVar3 [value=null], V_LIGHT_LEVEL=MySensorsVariableVLightLevel [value=null], V_VAR4=MySensorsVariableVVar4 [value=null], V_VAR5=MySensorsVariableVVar5 [value=null]}]}

==> /var/log/openhab2/events.log <==

2018-08-15 23:58:05.800 [hingStatusInfoChangedEvent] - 'mysensors:light-level:mygateway1:PukuhValoisuus' changed from UNINITIALIZED (BRIDGE_UNINITIALIZED) to INITIALIZING

==> /var/log/openhab2/openhab.log <==

2018-08-15 23:58:05.769 [DEBUG] [ensors.handler.MySensorsThingHandler] - Event listener for node 5-6 not registered yet, registering...

2018-08-15 23:58:05.783 [DEBUG] [rs.internal.gateway.MySensorsGateway] - Merging child map: {14=MySensorsChild [childId=14, nodeValue={V_VAR1=MySensorsVariableVVar1 [value=null], V_LEVEL=MySensorsVariableVLevel [value=null], V_VAR2=MySensorsVariableVVar2 [value=null], V_VAR3=MySensorsVariableVVar3 [value=null], V_LIGHT_LEVEL=MySensorsVariableVLightLevel [value=null], V_VAR4=MySensorsVariableVVar4 [value=null], V_VAR5=MySensorsVariableVVar5 [value=null]}]} with: {15=MySensorsChild [childId=15, nodeValue={V_VAR1=MySensorsVariableVVar1 [value=null], V_VAR2=MySensorsVariableVVar2 [value=null], V_VAR3=MySensorsVariableVVar3 [value=null], V_VAR4=MySensorsVariableVVar4 [value=null], V_VAR5=MySensorsVariableVVar5 [value=null], V_TEMP=MySensorsVariableVTemp [value=null], V_ID=MySensorsVariableVId [value=null]}]}

2018-08-15 23:58:05.795 [DEBUG] [ensors.handler.MySensorsThingHandler] - Event listener for node 1-14 not registered yet, registering...

2018-08-15 23:58:05.858 [DEBUG] [rs.internal.gateway.MySensorsGateway] - Merging child map: {14=MySensorsChild [childId=14, nodeValue={V_VAR1=MySensorsVariableVVar1 [value=null], V_LEVEL=MySensorsVariableVLevel [value=null], V_VAR2=MySensorsVariableVVar2 [value=null], V_VAR3=MySensorsVariableVVar3 [value=null], V_LIGHT_LEVEL=MySensorsVariableVLightLevel [value=null], V_VAR4=MySensorsVariableVVar4 [value=null], V_VAR5=MySensorsVariableVVar5 [value=null]}], 15=MySensorsChild [childId=15, nodeValue={V_VAR1=MySensorsVariableVVar1 [value=null], V_VAR2=MySensorsVariableVVar2 [value=null], V_VAR3=MySensorsVariableVVar3 [value=null], V_VAR4=MySensorsVariableVVar4 [value=null], V_VAR5=MySensorsVariableVVar5 [value=null], V_TEMP=MySensorsVariableVTemp [value=null], V_ID=MySensorsVariableVId [value=null]}]} with: {3=MySensorsChild [childId=3, nodeValue={V_VAR1=MySensorsVariableVVar1 [value=null], V_TRIPPED=MySensorsVariableVTripped [value=null], V_ARMED=MySensorsVariableVArmed [value=null], V_VAR2=MySensorsVariableVVar2 [value=null], V_VAR3=MySensorsVariableVVar3 [value=null], V_VAR4=MySensorsVariableVVar4 [value=null], V_VAR5=MySensorsVariableVVar5 [value=null]}]}

2018-08-15 23:58:05.866 [DEBUG] [ensors.handler.MySensorsThingHandler] - Event listener for node 1-15 not registered yet, registering...

==> /var/log/openhab2/events.log <==

2018-08-15 23:58:05.908 [hingStatusInfoChangedEvent] - 'mysensors:motion:mygateway1:PukuhLiike' changed from UNINITIALIZED (BRIDGE_UNINITIALIZED) to INITIALIZING

==> /var/log/openhab2/openhab.log <==

2018-08-15 23:58:05.902 [DEBUG] [ensors.handler.MySensorsThingHandler] - Event listener for node 1-3 not registered yet, registering...

==> /var/log/openhab2/events.log <==

2018-08-15 23:58:05.982 [hingStatusInfoChangedEvent] - 'mysensors:door:mygateway1:TalliSivuovi' changed from UNINITIALIZED (BRIDGE_UNINITIALIZED) to INITIALIZING

2018-08-15 23:58:06.050 [hingStatusInfoChangedEvent] - 'mysensors:lock:mygateway1:TalliSivuoviLukko' changed from INITIALIZING to ONLINE

2018-08-15 23:58:06.109 [hingStatusInfoChangedEvent] - 'mysensors:light-level:mygateway1:PukuhValoisuus' changed from INITIALIZING to ONLINE

2018-08-15 23:58:06.160 [hingStatusInfoChangedEvent] - 'mysensors:door:mygateway1:TalliSivuovi' changed from INITIALIZING to ONLINE

2018-08-15 23:58:06.202 [hingStatusInfoChangedEvent] - 'mysensors:temperature:mygateway1:BoilerTemp' changed from INITIALIZING to ONLINE

2018-08-15 23:58:06.253 [hingStatusInfoChangedEvent] - 'mysensors:motion:mygateway1:PukuhLiike' changed from INITIALIZING to ONLINE

==> /var/log/openhab2/openhab.log <==

2018-08-15 23:58:10.493 [DEBUG] [rotocol.mqtt.MySensorsMqttConnection] - MQTT message received. Topic: mysensors-out/1/14/1/0/23, Message: 0

2018-08-15 23:58:10.511 [DEBUG] [rotocol.mqtt.MySensorsMqttConnection] - Message topic part: 1/14/1/0/23

2018-08-15 23:58:10.526 [DEBUG] [rotocol.mqtt.MySensorsMqttConnection] - Converted MQTT message to MySensors Serial format. Sending on to bridge: 1;14;1;0;23;0

2018-08-15 23:58:10.542 [DEBUG] [rsAbstractConnection$MySensorsReader] - Message from gateway received: 1;14;1;0;23;0

2018-08-15 23:58:10.574 [DEBUG] [rs.internal.gateway.MySensorsGateway] - Node 1 found in gateway

2018-08-15 23:58:10.586 [DEBUG] [rotocol.mqtt.MySensorsMqttConnection] - MQTT message received. Topic: mysensors-out/1/15/1/0/0, Message: 53

2018-08-15 23:58:10.606 [DEBUG] [rotocol.mqtt.MySensorsMqttConnection] - Message topic part: 1/15/1/0/0

2018-08-15 23:58:10.591 [DEBUG] [rs.internal.gateway.MySensorsGateway] - Child 14 found in node 1

2018-08-15 23:58:10.619 [DEBUG] [rotocol.mqtt.MySensorsMqttConnection] - Converted MQTT message to MySensors Serial format. Sending on to bridge: 1;15;1;0;0;53

2018-08-15 23:58:10.661 [DEBUG] [ensors.handler.MySensorsThingHandler] - Updating channel: light-level(V_LIGHT_LEVEL) value to: 0

==> /var/log/openhab2/events.log <==

2018-08-15 23:58:11.034 [vent.ItemStateChangedEvent] - PukuhValoisuus changed from NULL to 0

==> /var/log/openhab2/openhab.log <==

2018-08-15 23:58:11.617 [DEBUG] [ensors.handler.MySensorsThingHandler] - Setting last update for node/child 1/14 to 2018-08-15T23:58:10.000+0300

2018-08-15 23:58:11.629 [DEBUG] [rsAbstractConnection$MySensorsReader] - Message from gateway received: 1;15;1;0;0;53

2018-08-15 23:58:11.642 [DEBUG] [rs.internal.gateway.MySensorsGateway] - Node 1 found in gateway

2018-08-15 23:58:11.657 [DEBUG] [rs.internal.gateway.MySensorsGateway] - Child 15 found in node 1

2018-08-15 23:58:11.671 [DEBUG] [ensors.handler.MySensorsThingHandler] - Updating channel: temp(V_TEMP) value to: 53

==> /var/log/openhab2/events.log <==

2018-08-15 23:58:11.758 [vent.ItemStateChangedEvent] - BoilerTemp changed from NULL to 53

==> /var/log/openhab2/openhab.log <==

2018-08-15 23:58:11.770 [DEBUG] [ensors.handler.MySensorsThingHandler] - Setting last update for node/child 1/15 to 2018-08-15T23:58:11.000+0300

2018-08-15 23:58:47.461 [DEBUG] [rotocol.mqtt.MySensorsMqttConnection] - MQTT message received. Topic: mysensors-out/1/14/1/0/23, Message: 0

2018-08-15 23:58:47.482 [DEBUG] [rotocol.mqtt.MySensorsMqttConnection] - Message topic part: 1/14/1/0/23

2018-08-15 23:58:47.495 [DEBUG] [rotocol.mqtt.MySensorsMqttConnection] - Converted MQTT message to MySensors Serial format. Sending on to bridge: 1;14;1;0;23;0

2018-08-15 23:58:47.513 [DEBUG] [rsAbstractConnection$MySensorsReader] - Message from gateway received: 1;14;1;0;23;0

2018-08-15 23:58:47.533 [DEBUG] [rs.internal.gateway.MySensorsGateway] - Node 1 found in gateway

2018-08-15 23:58:47.565 [DEBUG] [rotocol.mqtt.MySensorsMqttConnection] - MQTT message received. Topic: mysensors-out/1/15/1/0/0, Message: 53

2018-08-15 23:58:47.556 [DEBUG] [rs.internal.gateway.MySensorsGateway] - Child 14 found in node 1

2018-08-15 23:58:47.579 [DEBUG] [ensors.handler.MySensorsThingHandler] - Updating channel: light-level(V_LIGHT_LEVEL) value to: 0

2018-08-15 23:58:47.597 [DEBUG] [rotocol.mqtt.MySensorsMqttConnection] - Message topic part: 1/15/1/0/0

2018-08-15 23:58:47.612 [DEBUG] [rotocol.mqtt.MySensorsMqttConnection] - Converted MQTT message to MySensors Serial format. Sending on to bridge: 1;15;1;0;0;53

2018-08-15 23:58:47.719 [DEBUG] [ensors.handler.MySensorsThingHandler] - Setting last update for node/child 1/14 to 2018-08-15T23:58:47.000+0300

2018-08-15 23:58:47.731 [DEBUG] [rsAbstractConnection$MySensorsReader] - Message from gateway received: 1;15;1;0;0;53

2018-08-15 23:58:47.750 [DEBUG] [rs.internal.gateway.MySensorsGateway] - Node 1 found in gateway

2018-08-15 23:58:47.765 [DEBUG] [rs.internal.gateway.MySensorsGateway] - Child 15 found in node 1

2018-08-15 23:58:47.778 [DEBUG] [ensors.handler.MySensorsThingHandler] - Updating channel: temp(V_TEMP) value to: 53

2018-08-15 23:58:47.839 [DEBUG] [ensors.handler.MySensorsThingHandler] - Setting last update for node/child 1/15 to 2018-08-15T23:58:47.000+0300

And my item & thing (in separate files of course):

Number PukuhValoisuus   "Pukuhuone valoisuus [%.1f %]"  <719914_monitor> {channel="mysensors:light-level:mygateway1:PukuhValoisuus:light-level"}

light-level PukuhValoisuus [nodeId=1, childId=14]

@timo Firstly, I am very thankful for your help.
I changed that item and it started receiving values! I think there's something wrong with my light-level sensor's syntax too.

In console I did: log:set DEBUG.
That prints out hundreds and hundreds of lines....should I narrow the search somehow?