The nRF24L01+ is a simple & cheap 2.4GHz transceiver chip (you can buy 10 for $10). It has 8 pins, and we'll use 7 of them (we don't need IRQ). You can find the right orientation by looking for the ground pin which is marked in its own little square.
With Male-to-Female Dupont wires, you'll connect 7 wires using the mapping in the table below. The Arduino has multiple GND pins - it doesn't matter which you use.
|nRF24L01+||Arduino (Uno, Nano)|
With Female-to-Female Dupont wires, you'll connect 7 wires using the mapping in the table below. Your Pi might come with a pin layout sheet. If not, here's a very good one that works for both the B and B+ and includes a PDF you can print for easy reference.
|nRF24L01+||Raspberry Pi (B/B+)|
|MOSI||MOSI (19)||MISO||MISO (21)|
When you're done, your setup will look similar to this:
I think one of the wires is in the wrong Arduino pin in this picture...
Now we need to install some libraries for the Pi and Arduino so they understand what to do with these modules.The RF24 Libraries