RFM69HW and Uno

[chalupien]

Ok so I've been reading around that I need a voltage divider or level shifter to communicate between the 5v uno and the 3.3v RFM69. However I have the example sketches running on two uno's with the rfm powered by the 5V output. I tested the Voltage going into the RFM and it's 5.2V and 4.8V. Reading that this will damage the RFM? It seems to work just fine... Why? and Is this bad?

[Felix]

I tested the Voltage going into the RFM and it's 5.2V and 4.8V. Reading that this will damage the RFM? It seems to work just fine... Why? and Is this bad?

Oops, maybe not for long...

[chalupien]

So at the minimum Ill need to shift the voltage down by passing it through a series of 10k/4.7k or 2.2k/1k resistors? What size can these be? 1/4W 1/6W??

Nick

[Felix]

They are signal shifters so minimal current will leak, get the smallest you can handle