Wait for packet without spinning 100% cpu?

Hi i've looked at the examples but the answer to my question is not clear to me. Which method calls would I use to wait for a packet to arrive, with a timeout, without using 100% CPU while I wait? Using this I get 100% cpu usage:

LoRa.request(LoRa.RX_CONTINUOUS)
LoRa.wait(30)

Thanks and great work on this library!