I'm wondering if the radio can handle automatically ACKing on its own? The demo code seems to have the arduino sending the ACK's, not the RFM69. The datasheet makes just a single, vague reference to AutoRxACK, but it describes it as "automatic reception of acknowledge," which sounds different anyway. Is that it, or does it go by some other name?
As a point of comparison, some radios (e.g. NRF24L01+) do have the capability to auto ACK, and I'm trying to find out if the
RFM69 is one of them.