Skip to the end for a less narrative TLDR.

I’m working on a pendant right now, and as part of it I’ve been playing with ESP32s. I impulse-bought a dev-board from Jaycar - which, wonderfully, doesn’t come with any documentation! Luckily, there’s plenty online, but it’s generic and a bit out of date. In particular, getting drivers setup for the CH340 serial-to-usb chip was harder than expected, so I thought write up a quick summary of how I got it working in case it helps anyone.

For searchability’s sake, the board is a Duinotech ESP32 Wearable Development Board (part number: XC3810).

With that out of the way…

Setting up a CH340 drivers on Linux Mint in 2023.

I’m using the Arduino IDE for this.

First problem upon plugging in: nothing showed up in my ports section. I checked lsusb, and couldn’t see anything. If this happens to you, try a different USB cable. Then try another. Pretty sure your USB cable isn’t the problem? Try a couple more times. It took me about 5 different cables until I found one that worked, and turns out I’d wasted an hour of debugging time over it!

Next up, we need the drivers. The CH340 drivers are no longer installed by default in Ubuntu or Mint. This can be downloaded from the manufacturer’s website - this is the latest version as of writing.

A lot of websites say this driver doesn’t work, but it’s actually been patched since! It worked correctly, but the serial port wasn’t recognised by arduino - I’m guessing because it makes the serial port ttyCH340USB0 instead of ttyusb0? (I imagine there’s a config you can change)

The solution that worked was the patched version of the older drivers, found here:

Finally, as noted in the page above: there is a bug in brltty (a library for braille reader devices) that prevents the drivers from attaching to the chip. You either need to upgrade brltty to 6.5 or uninstall it.Do not do this if you need a braille reader, for obvious reasons.

After changing all of this, it worked!

Generic ESP32 Programming

One the drivers are installed and the port shows up in the Arudino IDE, the programming was quite simple. I used the official ESP32 library setup guide: Installing using Arduino IDE.

The one modification I required was installing pyserial manually. If you have pip3 installed, this is as simple as pip3 install pyserial.

One this was done, I simply set my board to ESP32 Dev Board and it worked! The lack of pinout messed with me for a while, but after checking with a continuity tester I found that the numbers on the board align with the GPIO pin numbers of the ESP32 pinout (I used this for refrerence).

With that, everything worked!

…shit, this display only works with 5V.


If you’re having issues with a CH340 (or probably CH341):

  • First, check lsusb to see if the board is connected. The best way is to run the command with the board plugged in and removed, and see if anything changes.
  • If you don’t see it, try a different cable and different USB ports. Keep trying cables until it shows up. It took me about 10 different cables before I found one that worked.
  • Next, install the CH340 drivers. Try the drivers from the manufacturer’s website first: here. If this doesn’t work, try the older patched version.
  • Make sure your user is part of the dialout group. This can be done via sudo usermod -a -G dialout $USER.
  • Finally, you may need to uninstall brltty (this is the braille reader daemon, so be careful if you require one!).