RFM69 radio 915Mhz

[karelsmits]

Hi,
I am using an RFM69 radio 915Mhz. I have two devices set up. 1 Arduino Uno R3 and 1 Arduino nano. When I set it up for mysensors, it doesn’t work. I have the NRF24L01 on both devices and then it does works, but when I connect the devices to the RFM69 radio, it doesn’t work. I connected the RFM69 radio to the 3.3 v port of the Nano and Uno devices. When I saw that with mysensors I get the tsm failed error message, I used the basic script of the RFM69 radio to connect 2 radios. There I saw that it transmits only single letters/messages, without problem, and it only does it for a little, it stops after a couple of characters sent. Code is at: https://learn.sparkfun.com/tutorials/rfm69hcw-hookup-guide#hardware-connections. I used a capacitor between vcc and ground on the radios. I connect the radio direct to the board, without using resistors… just like: https://www.mysensors.org/build/connect_radio .
My thought is that the issue is a power issue. How would I be able to take care of this issue, being that I am using a capacitor and feeding it from the 3.3 v output of the nano/uno.
Is it possible that the issue is something else? What are your thoughts? What should be done?
P.S.: I am using a 915Mhz antenna, so the antenna is not an issue, as I even do get response when it does work.
Thank you very much!!

[nagelc]

Unlike the NRF24, the RFM69 is not 5V tolerant on the data pins. The Uno and Nano both have 5V data pins. The NRF24 can work with them as long as it has the 3.3V supply. Unfortunately, the RFM69 needs the data pins to be 3.3V also.
I have used the RFM69 915Mhz successfully with a 3.3V ProMini (all pins 3.3V). To use with the Uno or Nano, you would need to power from the 3.3V supply and use a 5V to 3.3V level shifter on the NSS, MOSI, and SCK data pins.

[gohan]

There are few users that have rfm69 working on 5v Arduino, but it is out of specs. So, as said before, go with a level shifter or use 3.3v hardware like pro mini 3.3v for nodes and raspberry pi for gateway

[karelsmits]

@nagelc said in RFM69 radio 915Mhz:

5V to 3.3V level shifter

thank you all

[karelsmits]

@nagelc
just btw, could it also be a current issue. that the nano isn't able to provide enough current to the RFM69.

Thank you!

[nagelc]

@karelsmits
I'm afraid I don't know enough about the hardware to answer. I didn't have any luck with the RFM69 on the Nano, so I switched to the 3.3V ProMini. I used a Moteino USB for my serial gateway. It's a more expensive option, but it was easy to implement and has been very reliable.