user57281: I have the LiquidCrystal library installed but all the examples are for 4bit connection, I want to drive the LCD with 8bit.
In LiquidCrystal.cpp file it says;

When the display powers up, it is configured as follows:
DL = 1;  8-bit interface data

But what's is the function, should it be like this: LiquidCrystal DL(1);? where and how should I call DL = 1;?

user4143: You don't "do" anything to enable 8 bit. As it says when the device powers up the DL bit in the configuration is already set, enabling 8 bit.
You just need to wire it for 8 bit and specify all 8 bits of wiring in the constructor.
The manual entry for the constructor shows you what parameters you can specify:

https://www.arduino.cc/reference/en/libraries/liquidcrystal/liquidcrystal/


57281: <p>I have the <a href="https://github.com/arduino-libraries/LiquidCrystal" rel="nofollow noreferrer">LiquidCrystal</a> library installed but all the examples are for 4bit connection, I want to drive the LCD with 8bit.</p>
<p>In <a href="https://github.com/arduino-libraries/LiquidCrystal/blob/master/src/LiquidCrystal.cpp" rel="nofollow noreferrer">LiquidCrystal.cpp</a> file it says;</p>
<blockquote>
<p>When the display powers up, it is configured as follows:</p>
<p>DL = 1;  8-bit interface data</p>
</blockquote>
<p>But what's is the function, should it be like this: <code>LiquidCrystal DL(1);</code>? where and how should I call <code>DL = 1;</code>?</p>
 4143: <p>You don't &quot;do&quot; anything to enable 8 bit. As it says <em>when the device powers up the DL bit in the configuration is already set, enabling 8 bit</em>.</p>
<p>You just need to wire it for 8 bit and specify all 8 bits of wiring in the constructor.</p>
<p>The manual entry for the constructor shows you what parameters you can specify:</p>
<ul>
<li><a href="https://www.arduino.cc/reference/en/libraries/liquidcrystal/liquidcrystal/" rel="nofollow noreferrer">https://www.arduino.cc/reference/en/libraries/liquidcrystal/liquidcrystal/</a></li>
</ul>
