user15493: I have an issue with an Arduino Nano.
I want to communicate with it through the Serial-Port. Meaning I want to send and receive Serial commands. With USB and the "Serial Monitor" this works nice.
Now I have connected the COM-Port of the PC with Adruinos Digital Pins 0 and 1 (RX and TX) and a GND PIN. (3 Cables total).
Here is a minimal example of my Code:
void setup() {
  Serial.begin(9600,SERIAL_8N1);
  Serial.println("Start");
}


void loop() {
  Serial.println("Hello World");

  delay( 1000 );
}

The Serial Monitor says:
Start
Hello World
Hello World
Hello World
Hello World
...

Putty however says:
▒▒▒R▒▒▒t▒*▒▒▒R▒▒▒t▒*▒▒▒R▒▒▒t▒*▒▒▒R▒▒▒t▒*▒▒▒R▒▒▒t▒*▒::
                                                     ▒▒t▒*▒▒▒R▒▒▒t▒*▒▒▒R▒▒▒t▒*▒▒▒R▒▒▒t▒*▒▒▒R▒▒▒t▒*▒▒▒R▒▒▒t▒*▒▒▒R▒▒▒t▒*▒▒▒R▒▒▒t▒*▒▒    ▒R▒▒▒t▒*▒▒▒R▒▒▒t▒*

Putty is connected with 
- BaudRate: 9600
- Data Bits: 
- Stop Bits: 1
- Parity: None
- Flow Control: None
What is wrong here?
Update:
The PC has a 9-pin D socket (Image)
This is connected to a RS232 to RJ45 connector (image)
From the RJ45-Cable I used the Brown, Blue, and White/Green Cable to connect with the Arduino

user13432: RS232 is not TTL. You need a level converter. For more details see https://www.sparkfun.com/tutorials/215. 

15493: <p>I have an issue with an Arduino Nano.</p>

<p>I want to communicate with it through the Serial-Port. Meaning I want to send and receive Serial commands. With USB and the "Serial Monitor" this works nice.
Now I have connected the COM-Port of the PC with Adruinos Digital Pins 0 and 1 (RX and TX) and a GND PIN. (3 Cables total).</p>

<p>Here is a minimal example of my Code:</p>

<pre><code>void setup() {
  Serial.begin(9600,SERIAL_8N1);
  Serial.println("Start");
}


void loop() {
  Serial.println("Hello World");

  delay( 1000 );
}
</code></pre>

<p><strong>The Serial Monitor says:</strong></p>

<pre><code>Start
Hello World
Hello World
Hello World
Hello World
...
</code></pre>

<p><strong>Putty however says:</strong></p>

<pre><code>▒▒▒R▒▒▒t▒*▒▒▒R▒▒▒t▒*▒▒▒R▒▒▒t▒*▒▒▒R▒▒▒t▒*▒▒▒R▒▒▒t▒*▒::
                                                     ▒▒t▒*▒▒▒R▒▒▒t▒*▒▒▒R▒▒▒t▒*▒▒▒R▒▒▒t▒*▒▒▒R▒▒▒t▒*▒▒▒R▒▒▒t▒*▒▒▒R▒▒▒t▒*▒▒▒R▒▒▒t▒*▒▒    ▒R▒▒▒t▒*▒▒▒R▒▒▒t▒*
</code></pre>

<p>Putty is connected with 
- BaudRate: 9600
- Data Bits: 
- Stop Bits: 1
- Parity: None
- Flow Control: None</p>

<p>What is wrong here?</p>

<p>Update:
The PC has a 9-pin D socket (<a href="http://www.airyear.com/images/products1/202711.jpg" rel="nofollow">Image</a>)
This is connected to a RS232 to RJ45 connector (<a href="http://ecx.images-amazon.com/images/I/41BucionchL._SY300_.jpg" rel="nofollow">image</a>)
From the RJ45-Cable I used the Brown, Blue, and White/Green Cable to connect with the Arduino</p>
 13432: <p>RS232 is not TTL. You need a level converter. For more details see <a href="https://www.sparkfun.com/tutorials/215" rel="nofollow">https://www.sparkfun.com/tutorials/215</a>. </p>
