I started out with NRF 2.4 MHz radios for my 8 nodes MySensors and Domoticz. As I also install WiFi networks for customers and have access to our equipment at work I did a measurement at home because I could not get a reliable network.
First measurement revealed that my DECT wireless phone occupied the same channel that was the default for the NRF radios. And that my neighbors run their WiFi occupying all other channels. Equipment used was Ekahau.
I tried to tweak the channels but no avail.
So, I bought new radios, RFM833, and that was the end of my troubles. For two year now my eight nodes have not skipped a beat. I measure temperature, humidity, light (lux), UV and radioactivity.

And all my WiFi at home is at 5GHz as the 2.4 was exhausted.
I have about 40 NRF radios in a box with no use for them.

The code that you posted:
send(msg.set(value==HIGH ? 1 : 0))
Translates to this
If ”value” is HIGH (true) then send 1, if not send 0

It has nothing to do with PIN 0 or 1

The same goes for
digitalWrite(RELAY_PIN_1, loadState(CHILD_ID_RELAY1)?RELAY_ON:RELAY_OFF);
It translates to
On RELAY_PIN_1, if it’s state is 1 write HIGH to RELAY_PIN_1 else write LOW.

If you use serial in your sketch you can’t use PIN 0 or 1 as those pins are TX and RX.

Be aware that most of the cheap NRF boards from China are counterfeit. If you have those in an environment with a lot of WiFi you won’t get any range at all. And all “modifications” to improve range posted on YouTube are not any improvement.
You need to buy real NRF modules with external antenna.
Just my two cents.

I bought 20 of the Rev 10 Easy PCB boards from Openhardware, but could not get them to work with the flash memory.
See thread here: Bug in Easy PCB
So I just bite the dust and forgot about them. Until a couple of days ago when I decided to see if I could get them to work.
I modified the PCB and got them to work.

1. The unmodified board
2. Cut line between pin 7 and the capacitor and scrape of at the right of the C7.
3. Solder the capacitor, solder a blob from the capacitor to the scraping.
4. Solder a blob between pin 7 and 8 on the flash chip
5. Solder a piece of wire between pin 6 of the flash chip and pin 13 of the Arduino.

I then started to try to flash the Sensebender OTA firmware to my Arduinos. It was a No Go, I had tons of trouble until I decided to change the Arduino to another version that I had.
Sad to say, all Funduino Mini pro's that I have are all faulty.
I had some other Mini pro that was marked Deek-Robot, those worked like a charm.
I did some testing yesterday and was able to flash new firmware via OTA and MYSController.
More about that in an another thread as I found some quirks in the process of doing OTA.

@rodaman if you have bought real NRF modules you have been satisfied.
Or if you have bought RFM 433, 833 or 915 MHz radios you had been more that pleased.
Not MySensors fault.

I do, really easy to setup. I have decided to only show the temperatures and battery status when battery level is low.

I am using this:

// Bosch BME280 Embedded Adventures MOD-1022 weather multi-sensor Arduino code, 
// written originally by Embedded Adventures. 
// https://github.com/embeddedadventures/BME280
#include <BME280_MOD-1022.h>```

Change

lecture_adc = BAR_SENSOR_ANALOG_PIN;

To

lecture_adc = analogRead(BAR_SENSOR_ANALOG_PIN);

// Debug
#define MY_DEBUG
// Enable and select radio type attached
#define   MY_RADIO_RFM69
#define   MY_IS_RFM69HW
#define   MY_RFM69_NEW_DRIVER
#define   MY_RFM69_FREQUENCY RFM69_868MHZ
// #define   MY_RFM69_ENABLE_ENCRYPTION

#include <MySensors.h>

#define SKETCH_NAME    "Test-text"
#define SKETCH_VERSION "1.0"

#define CHILD_ID_RSSI_INFO  1

// Mysensors settings
MyMessage msgRSSI(CHILD_ID_RSSI_INFO, V_TEXT);

void before()
{
}

void setup()
{
  Serial.begin(115200); // for serial debugging.
  Serial.println(F("Start up sensor."));
}

void presentation()
{
  present(CHILD_ID_RSSI_INFO, S_INFO, "RSSI Info");
}

void loop()
{
#ifdef MY_DEBUG
  Serial.println(F("Starting new measurements"));
#endif
  CheckRSSI();
  // Sleep 
#ifdef MY_DEBUG
  Serial.println(F("Waiting 1 minute"));
#endif
  wait(60000);
}

Hi,
I am interested, and I live in Malmo Sweden

What version of the PCB did you order? The NRF24 or the RFM69?
I used the NRF24 but found it very unreliable and swapped all my sensors to RFM69.
As almost every NRF24 from china is fake you will find out that the range between sensor and gateway is a couple of meters.
The RFM69 (on 868 MHz) will have a range up to 50 meters and above. If used indoors it will easy go over 30 meters.

Here is a version that I downloaded a long time ago.
EDIT: It seems that I can't upload files. Bummer. PM me if you want the file.

Bug in MYScontroller.
When I edit the file firmware_config.csv and set a version number with a decimal the output in the debug is wrong.
This is my file:

Type,Name,Version,File,Comments
10,Blink,1,Blink.ino.hex,blinking example
20,Tvattstugan-2,3,Tvattstugan-2.ino.hex,Testar Flash
30,Tvattstugan,2,Tvattstugan.ino.hex,Tvattstugan
40,Sovrummet,2.1,Sovrummet.ino.hex,Sovrummet

Note that I have 2.1 as the version in 40, Sovrummet.
But when I load the repo in MYSController v is 65535:

2021-02-13 17:06:37	REPO	FW "Blink" loaded. t=10, v=1, blocks=80, crc=0x46D4
2021-02-13 17:06:37	REPO	FW "Tvattstugan-2" loaded. t=20, v=3, blocks=1488, crc=0x6D13
2021-02-13 17:06:37	REPO	FW "Tvattstugan" loaded. t=30, v=2, blocks=960, crc=0xBB4F
2021-02-13 17:06:37	REPO	FW "Sovrummet" loaded. t=40, v=65535, blocks=936, crc=0x6AB3
2021-02-13 17:06:37	REPO	FW repository loaded. Items=4

And in the GUI the version is also 65535.

Actually there are two bugs.
If I add (sloppy I know) more empty lines at the end in the firmware_config.csv file I get this in the debug:

2021-02-13 17:13:35	REPO	FW "Blink" loaded. t=10, v=1, blocks=80, crc=0x46D4
2021-02-13 17:13:35	REPO	FW "Tvattstugan-2" loaded. t=20, v=3, blocks=1488, crc=0x6D13
2021-02-13 17:13:35	REPO	FW "Tvattstugan" loaded. t=30, v=2, blocks=960, crc=0xBB4F
2021-02-13 17:13:35	REPO	FW "Sovrummet" loaded. t=40, v=65535, blocks=936, crc=0x6AB3
2021-02-13 17:13:35	ERROR	2107-15-31 is not a valid date specification

Other than that, great piece of software. Thanks.

I bought 20 of the Rev 10 Easy PCB boards from Openhardware, but could not get them to work with the flash memory.
See thread here: Bug in Easy PCB
So I just bite the dust and forgot about them. Until a couple of days ago when I decided to see if I could get them to work.
I modified the PCB and got them to work.

1. The unmodified board
2. Cut line between pin 7 and the capacitor and scrape of at the right of the C7.
3. Solder the capacitor, solder a blob from the capacitor to the scraping.
4. Solder a blob between pin 7 and 8 on the flash chip
5. Solder a piece of wire between pin 6 of the flash chip and pin 13 of the Arduino.

I then started to try to flash the Sensebender OTA firmware to my Arduinos. It was a No Go, I had tons of trouble until I decided to change the Arduino to another version that I had.
Sad to say, all Funduino Mini pro's that I have are all faulty.
I had some other Mini pro that was marked Deek-Robot, those worked like a charm.
I did some testing yesterday and was able to flash new firmware via OTA and MYSController.
More about that in an another thread as I found some quirks in the process of doing OTA.

I started with MySensors, Pro Mini and NRF24. I had tons of problems. I borrowed from work our WiFi scanner equipment and checked the 2.4 GHz. It was a total mess. Our DECT-phone almost killed the channel that was used for MySensors. And I discovered, as many has, the NRF24 was all counterfeit.
So, i trashed all NRF24 and moved to RFM69. That was nearly three years ago. My gateway is a Raspberry Pi.
My controller is Domoticz.
Conclusion, and a note to all MySensors users out there. Move away from NRF24 and go with RFM69, you will never look back.

The code that you posted:
send(msg.set(value==HIGH ? 1 : 0))
Translates to this
If ”value” is HIGH (true) then send 1, if not send 0

It has nothing to do with PIN 0 or 1

The same goes for
digitalWrite(RELAY_PIN_1, loadState(CHILD_ID_RELAY1)?RELAY_ON:RELAY_OFF);
It translates to
On RELAY_PIN_1, if it’s state is 1 write HIGH to RELAY_PIN_1 else write LOW.

If you use serial in your sketch you can’t use PIN 0 or 1 as those pins are TX and RX.

I started out with NRF 2.4 MHz radios for my 8 nodes MySensors and Domoticz. As I also install WiFi networks for customers and have access to our equipment at work I did a measurement at home because I could not get a reliable network.
First measurement revealed that my DECT wireless phone occupied the same channel that was the default for the NRF radios. And that my neighbors run their WiFi occupying all other channels. Equipment used was Ekahau.
I tried to tweak the channels but no avail.
So, I bought new radios, RFM833, and that was the end of my troubles. For two year now my eight nodes have not skipped a beat. I measure temperature, humidity, light (lux), UV and radioactivity.

And all my WiFi at home is at 5GHz as the 2.4 was exhausted.
I have about 40 NRF radios in a box with no use for them.

@rodaman if you have bought real NRF modules you have been satisfied.
Or if you have bought RFM 433, 833 or 915 MHz radios you had been more that pleased.
Not MySensors fault.

Be aware that most of the cheap NRF boards from China are counterfeit. If you have those in an environment with a lot of WiFi you won’t get any range at all. And all “modifications” to improve range posted on YouTube are not any improvement.
You need to buy real NRF modules with external antenna.
Just my two cents.

I do, really easy to setup. I have decided to only show the temperatures and battery status when battery level is low.