user8033: I think the arduino board is awesome.
Though I'm not interested in the library and IDE at all...
Is there a way, to use an AVR 328p, as you normally would, on an arduino board?
I like how arduino's can be programmed through serial, can get powered through serial and I often use serial as a debugging option. Making my own board (with ICSP programmer) would not be able to do this (withouth bootloader).

The Question
Do I have to use all the stuff from arduino?

Can I use my own compiler for an arduino board? (GNU-GCC / AVR)
Can I use my own IDE for an arduino board? (Eclipse / Atmel Studio)
Can I still program through serial then? (Does the bootloader care which compiler I used? Does Eclipse/AVR studio have the options to program through serial?)
Other stuff I should take in mind. (Annoying things like AVR studio not having a COM port window, though that's an easy fix.)

Edit: We've programmed an AVR 328P (GNU-GCC / Eclipse / ICSP) in school, so I know it takes quite some work to get the compiler set up, working with Eclipse. You don't have to completely describe the proces :) Just to avoid someone spending hours on an answer that's easily found on the internet.
(On my search for this subject I could only find people doing the other way around, getting an 328p chip to work with arduino)

user595: 
Do I have to use all the stuff from arduino?

A = No!

Can I use my own compiler for an arduino board? (GNU-GCC / AVR)
Can I use my own IDE for an arduino board? (Eclipse / Atmel Studio)
Can I still program through serial then? (Does the bootloader care which

Of Course! I use Eclipse IDE and I programming boards with Arduino bootloader directly in C/C++ using avr-gcc and avrdude.
Configuring Eclipse
First, let's download a plug-in for integrating AVR GCC and Avrdude + Eclipse IDE
To install the plug-in, point to the menu "Help> Install new software":

We will set a new location to download the plugin. Click the "Add ..." and type: AVR - Eclipse and the URL: http://avr-eclipse.sourceforge.net/updatesite

Now select the plugin that appeared in the list and click "Next":

Next, next, "I Acept the terms...", restart...
Now we install the plug-in, we will set it up. Point to the menu "Window> Preferences." Click in "AVRDUDE". The following screen:

On the next screen "AVR DUDE" let's set our recorder. Click "Add" to "Programmer configuration". Search for "Arduino".

Or, if you prefer, you can program making use of avr libraries in own Arduino IDE. Try to upload the following code into an Arduino board! While a blink costs almost 1,056 bytes of memory using an Arduino Uno, the following code uses only 164 bytes and does the same thing :)
#define F_CPU 16000000UL    
#include <avr/io.h>         
#include <util/delay.h>     

#define set_bit(Y,bit_x) (Y|=(1<<bit_x))    
#define clr_bit(Y,bit_x) (Y&=~(1<<bit_x))   
#define tst_bit(Y,bit_x) (Y&(1<<bit_x))     
#define cpl_bit(Y,bit_x) (Y^=(1<<bit_x))    

#define LED PB5         

int main( ){
    DDRB = 0xFF;        

    while(1){               
        cpl_bit(PORTB,LED); 
        _delay_ms(200);     
    }
}

If you use Linux, you can take a sudo cat/dev/ttyACM0 to detect what lies serial and echo "string" >> /dev/ttyACM0 to send data.

8033: <p>I think the arduino board is awesome.
Though I'm not interested in the library and IDE at all...
Is there a way, to use an AVR 328p, as you normally would, on an arduino board?</p>

<p>I like how arduino's can be programmed through serial, can get powered through serial and I often use serial as a debugging option. Making my own board (with ICSP programmer) would not be able to do this (withouth bootloader).</p>

<hr>

<p><strong>The Question</strong></p>

<p>Do I have to use all the stuff from arduino?</p>

<ul>
<li>Can I use my own compiler for an arduino board? (GNU-GCC / AVR)</li>
<li>Can I use my own IDE for an arduino board? (Eclipse / Atmel Studio)</li>
<li>Can I still program through serial then? (Does the bootloader care which compiler I used? Does Eclipse/AVR studio have the options to program through serial?)</li>
<li>Other stuff I should take in mind. (Annoying things like AVR studio not having a COM port window, though that's an easy fix.)</li>
</ul>

<p>Edit: We've programmed an AVR 328P (GNU-GCC / Eclipse / ICSP) in school, so I know it takes quite some work to get the compiler set up, working with Eclipse. You don't have to completely describe the proces :) Just to avoid someone spending hours on an answer that's easily found on the internet.
(On my search for this subject I could only find people doing the other way around, getting an 328p chip to work with arduino)</p>
 595: <ol>
<li>Do I have to use all the stuff from arduino?</li>
</ol>
<p>A = No!</p>
<ol start="3">
<li>Can I use my own compiler for an arduino board? (GNU-GCC / AVR)</li>
<li>Can I use my own IDE for an arduino board? (Eclipse / Atmel Studio)</li>
<li>Can I still program through serial then? (Does the bootloader care which</li>
</ol>
<p>Of Course! I use <code>Eclipse IDE</code> and I programming boards with Arduino bootloader directly in <code>C/C++</code> using avr-gcc and avrdude.</p>
<h2><strong>Configuring Eclipse</strong></h2>
<p>First, let's download a plug-in for integrating <code>AVR GCC</code> and <code>Avrdude</code> + <code>Eclipse IDE</code></p>
<p>To install the plug-in, point to the menu &quot;Help&gt; Install new software&quot;:</p>
<p><img src="https://i.stack.imgur.com/gPhH1.jpg" alt="enter image description here" /></p>
<p>We will set a new location to download the plugin. Click the &quot;Add ...&quot; and type: AVR - Eclipse and the URL: <a href="http://avr-eclipse.sourceforge.net/updatesite" rel="nofollow noreferrer">http://avr-eclipse.sourceforge.net/updatesite</a></p>
<p><img src="https://i.stack.imgur.com/Cuc1E.jpg" alt="enter image description here" /></p>
<p>Now select the plugin that appeared in the list and click &quot;Next&quot;:</p>
<p><img src="https://i.stack.imgur.com/MTTEJ.jpg" alt="enter image description here" /></p>
<p>Next, next, &quot;I Acept the terms...&quot;, restart...</p>
<p>Now we install the plug-in, we will set it up. Point to the menu &quot;Window&gt; Preferences.&quot; Click in &quot;AVRDUDE&quot;. The following screen:</p>
<p><img src="https://i.stack.imgur.com/lQy8i.jpg" alt="enter image description here" /></p>
<p><strong>On the next screen &quot;AVR DUDE&quot; let's set our recorder. Click &quot;Add&quot; to &quot;Programmer configuration&quot;. Search for &quot;Arduino&quot;.</strong></p>
<p><img src="https://i.stack.imgur.com/HLsHL.jpg" alt="enter image description here" /></p>
<p>Or, if you prefer, you can program making use of avr libraries in own Arduino IDE. Try to upload the following code into an Arduino board! While a blink costs almost 1,056 bytes of memory using an Arduino Uno, the following code uses only 164 bytes and does the same thing :)</p>
<pre><code>#define F_CPU 16000000UL    
#include &lt;avr/io.h&gt;         
#include &lt;util/delay.h&gt;     

#define set_bit(Y,bit_x) (Y|=(1&lt;&lt;bit_x))    
#define clr_bit(Y,bit_x) (Y&amp;=~(1&lt;&lt;bit_x))   
#define tst_bit(Y,bit_x) (Y&amp;(1&lt;&lt;bit_x))     
#define cpl_bit(Y,bit_x) (Y^=(1&lt;&lt;bit_x))    

#define LED PB5         

int main( ){
    DDRB = 0xFF;        

    while(1){               
        cpl_bit(PORTB,LED); 
        _delay_ms(200);     
    }
}
</code></pre>
<p>If you use Linux, you can take a <code>sudo cat/dev/ttyACM0</code> to detect what lies serial and <code>echo &quot;string&quot; &gt;&gt; /dev/ttyACM0</code> to send data.</p>
