Thank you very much for suggestions. I will try to check that over the weekend, then I will let you know about my results. In the meantime if someone has any other ideas why it doesn't work or how to debug it somehow I would appreciate.

I could borrow scope for the weekend. Could you tell me what should I searching for in this signals?

And when I changed it - PRO Mini as reciever and my homeboard as transmitter I got nothing. Homeboard is claiming that it is sending something, but it isn't getting to working node. Even trash data.

I didn't have pullup, but I don't have any more SPI decives also. But still - I added it as you sugested and still the same.

I have also one node which is working (Arduino PRO Mini connected with RFM69 module. And I tried test radio module also with that code:
https://learn.adafruit.com/adafruit-rfm69hcw-and-rfm96-rfm95-rfm98-lora-packet-padio-breakouts/rfm69-test. I used working node as transmitter and my homemade board as receiver.

And instead of "Hello World" I am getting some trash data:

I don't have level converter on my board, I forget about it, so I connected it outside the board. So MOSI, MISO, SCK and NSS goes to level converter and then to Atmega328p which is powered with 5V. Exactly that one from your link.

I am using Arduino UNO board for testing. I am powering circuit with 5V because I don't have any programmer (only Arduino board). So RX/TX for communication and programming have also 5V.

This 1K omh resistors on SPI line could cause problem or they shouldn't?

For now I am using Arduino Board as a supply for 5V and 3.3V. I tried also voltage converter. And no effect.

I got myself a new one RFM69 and unfortunately it haven't changed anything. Still the same problem. Any other ideas?

Hello there,

I recently build PCB board for mysensor node with Atmega328P. Microcontroller is working great with no problem. But there is no connection to RFM module. I have tried to debugg in on my own and get to this that is stucking on this line:

do writeReg(REG_SYNCVALUE1, 0xaa); while (readReg(REG_SYNCVALUE1) != 0xaa)

And nothing happens next. No serial communication, nothing. What can be the problem? I checked connections between the micro and RFM69 and everything seems okay.

It's connected of course through level converter to get 3.3V (but I have to say that accidentaly I connected if for 1-2 minutes to 5V pins - But I don't know - it could cause my rfm module break?).

I also attached schematic of my connection.

Thank your for help. I am fighting with that for last 3 days