low power receiver?

[detz]

What's the best option for a low power (battery) receiver? I'm assuming it can't really sleep since it has to always be listening but is there a low power option on the RFM69 chip?

[Felix]

If you search in the forum you will find plenty of topics on the subject.
The TL;DR is that you can't receive when you're not in RX mode. Not with RFM69 or any other receiver in this universe.
The "low power modes" simply loop between sleep and RX mode, thus reducing the power, but also the chance of receiving a packet.

[TomWS]

... it can't really sleep since it has to always be listening...

And you believe this because of some religious conviction?  I'm being purposefully facetious, but, really, you need to rethink this premise...

T

[ColinR]

The best premise for low-power operation is that communication is always initiated by the remote node.

C

[TomWS]

The best premise for low-power operation is that communication is always initiated by the remote node.

C

who is otherwise sleeping.

[Felix]

Right, however when the remote node sends periodic messages that tends to interfere with regulations which is a whole different can of worms.

[detz]

For example, if I wanted to have a battery powered repeater I couldn't sleep since it would always have to be listening, correct? I could still disable stuff (ADC, BO, etc) but wouldn't want to actually sleep.

[Felix]

You are correct. You could implement a cyclic sleep/RX where your sleepy node sleeps part of the time and the end node would retry enough times to hit the RX time of the repeater. It's a tradeoff. Repeaters should be ON for the best reliability, perhaps powered/charged via solar power.