radio.write () always returns 0
I hope you resolved your issue by now, but I had the same problem with an Arduino UNO/nRF24l01+ combination and this question was one of the search results.
In my case, the write() call returned false, but the receiver received the message.
As soon as I added one of the ubiquitous Adapter Boards into the mix the write() call started returning true.
My uneducated guess is that the sending and then the switch from transmit to receive and then waiting to receive the ACK used a bit too much power or something like that.
In any case, even though everyone recommends adding a capacitor and I had the adapter boards on hand, I had thought to tough it out without one and see how far I could get.
I kicked myself for the wasted time, but I learned a lot in the process and I'm having a lot of fun with the transceiver boards now. I'm glad that I didn't just shrug and say &quot;well the message got through so who cares?&quot;