RFM69 - not receiving?

[chbla]

Hi there,

I've got two RFM69HC 434Mhz, connected to two Arduino Nano 3 clones.

The code I use for testing is this:
https://gist.github.com/solars/44b2398e62d07e29314538a70579663f
(it's from sparkfun: https://learn.sparkfun.com/tutorials/rfm69hcw-hookup-guide/running-the-example-code)

When I enter something in the serial console it seems to be sending. The LED flashes quickly.
However, there is nothing received on the other side. If I eneable ACK I just get the 'no ack received' msg.

Can anyone spot the error? Is it maybe because I don't have a HCW, any settings wrong?

Thank you very much

[chbla]

When asking on mysensors I noticed that the RFM69 is not 5V tolerant on the inputs The blog post I took the
wiring from didn't mention that.

Being rather new to this, is it possible to adjust the level with resistors or do I need something else?