user63723: This is the board I will be referring to.

There are different variations of it (with built in buttons etc.) but they all seem to be based on the CH340 chip.
My problem is, that I do not know what the pinouts on the board stand for. I cannot find any schematics for the adapter (I can find some for the CH340). Does anyone have a clue as to what the different pins are for?

user71575: This module appears to be designed for communicating with the ESP8266 ESP-01 board. The pinout for the ESP-01 is shown below, taken from a typical datasheet:

[Updated]The arrow on the CH340 board next to the yellow header indicates the connection orientation. The bulk of the ESP-01 goes on the side of the header pointed to by the arrow, covering the CH340 board, as shown below.

Information on the WCH CH340 product set including the G model is here.

There is plenty of online information on getting started with the ESP8266 ESP-01 using the Arduino IDE. A good example is at instructables.com.
The other model variations you mentioned (with built in buttons) are probably in response to a known problem with this board when flashing ESP-01s. See here for more info.

63723: <p><a href="https://minielektro.dk/dev-10053.html?gclid=CjwKCAjwyryUBhBSEiwAGN5OCIxnaU5lCMS4IczQlnlLFWL2wgJWJj6RQ1qy8xyN4i50NNoEWv6rqBoCLuUQAvD_BwE" rel="nofollow noreferrer">This</a> is the board I will be referring to.
<a href="https://i.stack.imgur.com/tgJ9f.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/tgJ9f.jpg" alt="Board image" /></a></p>
<p>There are different variations of it (with built in buttons etc.) but they all seem to be based on the CH340 chip.</p>
<p>My problem is, that I do not know what the pinouts on the board stand for. I cannot find any schematics for the adapter (I can find some for the CH340). Does anyone have a clue as to what the different pins are for?</p>
 71575: <p>This module appears to be designed for communicating with the <a href="https://en.wikipedia.org/wiki/ESP8266" rel="nofollow noreferrer">ESP8266 ESP-01</a> board. The pinout for the ESP-01 is shown below, taken from a typical <a href="https://www.microchip.ua/wireless/esp01.pdf" rel="nofollow noreferrer">datasheet</a>:</p>
<p><a href="https://i.stack.imgur.com/uycDa.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/uycDa.png" alt="ESP-01 Pinout" /></a></p>
<p>[Updated]The arrow on the CH340 board next to the yellow header indicates the connection orientation. The bulk of the ESP-01 goes on the side of the header pointed to by the arrow, covering the CH340 board, as shown below.</p>
<p><a href="https://i.stack.imgur.com/Y4LU2.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Y4LU2.jpg" alt="connection orientation" /></a></p>
<p>Information on the WCH CH340 product set including the G model is <a href="http://www.wch-ic.com/products/CH340.html" rel="nofollow noreferrer">here</a>.</p>
<p><a href="https://i.stack.imgur.com/OrWNG.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/OrWNG.png" alt="CH340G pinout" /></a></p>
<p>There is plenty of online information on getting started with the ESP8266 ESP-01 using the Arduino IDE. A good example is at <a href="https://www.instructables.com/Getting-Started-With-Esp-8266-Esp-01-With-Arduino-/" rel="nofollow noreferrer">instructables.com</a>.</p>
<p>The other model variations you mentioned (with built in buttons) are probably in response to a known problem with this board when flashing ESP-01s. See <a href="https://www.instructables.com/USB-to-ESP-01-Board-Adapter-Modification/" rel="nofollow noreferrer">here</a> for more info.</p>
