Hi,
The nRF24L01 modules are totally ten years old but I still find mine very useful and continue to build stuff that use them.
Recent project was an nRF24L01+ receiver that outputs via serial/UART. I am a huge fan of the Nordic FOB that SFE doesnt make anymore. I ended up building a bunch of FOBs myself. So I also built this small receiving device. It uses an ATTiny84A and a Nordic nRF24L01+. It receives the button presses from the FOB and then outputs the value via serial. The key thing is that it only uses one pin to connect to the main uC and separates out all the SPI and decoding work. It also frees up some pins. I have some projects that use bluetooth SPP or xbees, so now I can swap in this nordic board like it was one of those. The nRF24L01+ is regulated to 3.3v and the ATTiny84A runs off whatever comes in (which better be 5v or less). It is working great.
I made a version that I programmed to be a “Poor Man’s 2.4 GHz Scanner”. It scans and then outputs over serial. So it is a quick hookup to an ftdi board to a terminal, and I can check what channels may be in conflict where I am.
I have included a couple pics. I went overboard with the leds and most can be left off. I also included an RX pin, but dont use it yet. The board needed to be small/narrow enough (0.6"x1.4") to fit inside some flow props and toys, like hula hoop tubing.
ben