Battery powered RFMxx gateway, how to save power?

I had yesterday a call with @Andreas about some strategies to get a solar powered gateway working.

You can move a node in a convenient way to a power saving device: Just switch off power for hungry components and send the MCU to sleep. This is difficult to do for a geteway because a gateway has to listen all the time supposed it does not know whe new packages arrive from the nodes.

So we discussed yesterday if it is possible that an IRQ can wake up a sleeping MCU and it seems to be possible see:

There is very high “listening current” for the RFM described so we have to tweak things here also but it seems a good starting point.

Hello Clemens,
as the Arduino-ESP8266 wifi firmware now works great even out-of-the-box, even when adopting the WeMoS D1 pro, I ordered some RFM69 and 95 LoRa in order to perform tests on radio firmware. I will also take your inputs to try to make the radio nodes and the gateway (I was thinking about also making a radio-wifi gateway) efficient in terms of power. Of course, I think we will have to make some PCB in order to make something similar to the (expensive) moteino (e.g. external UART module, usage of bosch BME280, etc.,)
In the meanwhile, I will be characterizing the wifi node in terms of power and search of candidate cheap energy harvesting methods, and also will try to make the H support like the ones depicted within hiveeyes website.

For the RFM69 we have successfully tested the RFM lib from Felix Rusu / Moteino. The RFM95 is working with the RadioHead lib. Perhaps it makes sens to use only one lib for both RFMs in the future. The downside of the RFM95 is that there is no hardware encryption so there may be some reasons to use still the RFM69 modules even with shorter range.

I don’t know if there is really a need for a battery powered radio–Wifi gateway. In case you have Wifi nearby you have often a power socket nearby. So my first goal would be radio-GSM gateway for battery operation.

I made some shields for the RFM69 (nodes) supporting an Arduino Pro (not Mini!) or Seeeduino Stalker, see Open Hive Shield for Seeeduino Stalker / Arduino Pro (3.3 V) and Yun / Uno (5 V)

A cheap CN3065 breakout and a solar cell could be enough for an ESP. I got good results with an one per Hour update interval and an ESP8266 (Adafruit Huzzah, see Open Hive WiFi Solar / Adafruit HUZZAH )