Hi, there are some infos concerning RFM70 but I haven't found what I was looking for. I have connected 2 RFM70 to 2 ATXMEGA 128 and it works pretty well and at reasonable distances (2 floors) but only when sender and receiver aren't moving. When I walk around with the receiver some data pakets are lost. My program always has the auto-ack-function enabled. Also I tried the auto-retransmission function. Then, after 15 tries of this function, I switched on the Re-Use mechanism (REUSE_TX_PL) with a timeout (without switching off auto retransmission). This didn't work either. Still some pakets are lost. Sometimes, the receicer blocks and I can make it work again by a reset of the processor (but this is not my main problem) For my final purpose I need very reliable data transfer and the receiver will move around. Does anybody know whether successful auto-retransmission causes an interrupt? Thats not mentioned in the instructions. Does anybody have a suggestion how to make these transmissions safer? Shall I flush the transmission buffer and start transmission again after 15 tries of the auto-retransmission function? can it be a hardware problem (the parts are only plugged together but this seems to be OK). Thanks for any suggestions!!