This is the board I will be referring to. Board image

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?


1 Answer 1


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:

ESP-01 Pinout

[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.

connection orientation

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

CH340G pinout

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.

  • The orientation is indicated by the arrow on the board
    – Majenko
    May 27, 2022 at 4:38
  • Thanks @Majenko, yes I guessed that. Not being familiar with the board / ESP-01 I wasn’t sure how to interpret the arrow. Is it pointing to the side on which the bulk of the ESP-01 board should be?
    – RowanP
    May 27, 2022 at 6:05
  • 1
    Yes. The ESP-01 covers the main body of the board.
    – Majenko
    May 27, 2022 at 6:21
  • @RowanP Thank you very much for the help! Do you know by any chance, if it is possible to use it for general UART/Serial communication? Specifically, if I simply connect TX to my device's RX and vise versa, would there be anything against doing this? May 27, 2022 at 13:00
  • 1
    @GeorgeWTrump I have not used the board myself, but I’m confident you could use jumpers to connect the RX, TX, Gnd, and maybe Vcc as you would for any CH340 adapter.
    – RowanP
    May 27, 2022 at 13:07

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