user20243: When I wanted to test my Nrf24L01 I wanted to be sure of it working fine, so I used this code for an Arduino Uno: 
#include <SPI.h>
#include <RF24.h>
#include "printf.h"
#define RF_CS 9
#define RF_CSN 7
RF24 radio(RF_CS, RF_CSN);
void setup() {
  Serial.begin(9600);
  printf_begin();
  radio.begin();
  radio.printDetails();
}
void loop() {
  radio.printDetails();
  delay(5000);

}

The thing is when I opened my Serial, I got this each 5 second: 
STATUS       = 0xff RX_DR=1 TX_DS=1 MAX_RT=1 RX_P_NO=7 TX_FULL=1
RX_ADDR_P0-1     = 0x0000000000 0x0000000000
RX_ADDR_P2-5     = 0xff 0xff 0x00 0x00
TX_ADDR      = 0x0000000000
RX_PW_P0-6   = 0xff 0x00 0x00 0xff 0xff 0x00
EN_AA        = 0xff
EN_RXADDR    = 0xff
RF_CH        = 0xff
RF_SETUP     = 0xff
CONFIG       = 0xff
DYNPD/FEATURE    = 0xff 0x00
Data Rate    = 1MBPS
Model        = nRF24L01
CRC Length   = 16 bits
PA Power     = PA_MAX

Which apparently means that there must be something wrong with the connection, as far as I know .
noting that i have this Nrf24L01 with 10 pins, so i tried to attach it just like the following picture shows : 

So I tried to plug it in with the Arduino just like this:

What was the mistake?

user19513: I think problem lies in your Arduino sketch, specifically in this line:
#define RF_CSN 7

Now, you have set RF_CSN pin to pin#7 while actually, its connected to pin#9
To get this to working you, try changing above lines of code to:
#define RF_CSN 10

Hope it helps.

20243: <p>When I wanted to test my Nrf24L01 I wanted to be sure of it working fine, so I used this code for an Arduino Uno: </p>

<pre><code>#include &lt;SPI.h&gt;
#include &lt;RF24.h&gt;
#include "printf.h"
#define RF_CS 9
#define RF_CSN 7
RF24 radio(RF_CS, RF_CSN);
void setup() {
  Serial.begin(9600);
  printf_begin();
  radio.begin();
  radio.printDetails();
}
void loop() {
  radio.printDetails();
  delay(5000);

}
</code></pre>

<p>The thing is when I opened my Serial, I got this each 5 second: </p>

<pre><code>STATUS       = 0xff RX_DR=1 TX_DS=1 MAX_RT=1 RX_P_NO=7 TX_FULL=1
RX_ADDR_P0-1     = 0x0000000000 0x0000000000
RX_ADDR_P2-5     = 0xff 0xff 0x00 0x00
TX_ADDR      = 0x0000000000
RX_PW_P0-6   = 0xff 0x00 0x00 0xff 0xff 0x00
EN_AA        = 0xff
EN_RXADDR    = 0xff
RF_CH        = 0xff
RF_SETUP     = 0xff
CONFIG       = 0xff
DYNPD/FEATURE    = 0xff 0x00
Data Rate    = 1MBPS
Model        = nRF24L01
CRC Length   = 16 bits
PA Power     = PA_MAX
</code></pre>

<p>Which apparently means that there must be something wrong with the connection, as far as I know .</p>

<p>noting that i have this Nrf24L01 with 10 pins, so i tried to attach it just like the following picture shows : </p>

<p><a href="https://i.stack.imgur.com/5epm9.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/5epm9.jpg" alt="enter image description here"></a></p>

<p>So I tried to plug it in with the Arduino just like this:
<a href="https://i.stack.imgur.com/PHuWb.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/PHuWb.png" alt="enter image description here"></a></p>

<p>What was the mistake?</p>
 19513: <p>I think problem lies in your Arduino sketch, specifically in this line:</p>

<pre><code>#define RF_CSN 7
</code></pre>

<p>Now, you have set RF_CSN pin to pin#7 while actually, its connected to pin#9</p>

<p>To get this to working you, try changing above lines of code to:</p>

<pre><code>#define RF_CSN 10
</code></pre>

<p>Hope it helps.</p>
