No maximum output from Hoperf RFM69H

Hi! I got strange problem with RFM69H radios. I have : 2x Arduino Pro mini dual power 5V/3.3V clones (power option set on 3.3V) 2x Hoperf RFM69H models (max power 100mW at 130mA) 2x external 3.3V power supplies

Based on this tutorial from Adafruit, I manage them to send/receive data.

Problem - in TX mode maximum power consumption is only 20mA (should be ~130mA), so I'm not using max potential of these modules (anyway - range is better than NRF24l01+).

Have tried both major libraries - RadioHead and LowPowerLabs - same result on both. Have tried modules from different vendors.

Does anyone who have these high power modules managed to get max power from them on standard Arduino(except original Moteino)?

My guess is problem with dual voltage arduino, so I already ordered pure 3.3V versions.

Any thoughts?

If you have it wired line the picture in their test set up, then you are getting what you should. 20 ma is all you can draw draw from that pin. Any more and you will need to power that unit from it's own power supply and connect the grounds together.


Power shouldn't be the issue - I'm using this step down module to provide stable 3.3V for Arduino and RFM69...

What are you using for an antenna?


I'm using 17cm straight copper wire. I know it's not fine tuned, but rssi is not issue ( I hope). I modified code and attached OLED display to RX side to display received pack number and rssi. Got more than 250m line of site without any lost pack.

Besides - good results with this antenna.

I doubt that you correctly measured the maximum current during transmit intervals.

My multimeter have function of max mA measurenemt. I turned RX device off for TX device to "do it's best" to send message. TX sketck sending messange after very 10 millis, so I think, that my measurements are ok. At least they could be wrong in small amplitude.