CH340 driver: when you need it and where to get it
CH340 is the USB chip that connects many cheap boards to a computer. If the board shows up as a serial port, you need nothing else. If it does not, try another cable first, then install the driver from WCH, the maker of the chip, and reconnect the board.
Updated November 6, 2026
How to check that the computer sees the board
- Windows: open Device Manager and look under Ports (COM & LPT) for USB-SERIAL CH340 with a COM number. A new line appears when you plug the board in.
- macOS: run
ls /dev/cu.*before and after plugging it in. A new line is the board. - Linux: run
lsusband look for1a86:7523. The port is usually/dev/ttyUSB0.
No new line at all usually means a charging cable. Try a cable that carries data before you install anything.
Where to get the driver
- Windows: CH341SER from WCH. Run it, press Install, reconnect the board.
- macOS: follow the WCH install guide. It has an extra step in the security settings.
- Linux: the
ch341driver is in the kernel since version 2.6.24, there is nothing to install.
Linux: the port exists but does not open
- On Ubuntu and similar systems the
brlttyservice can take the port. Remove it or turn it off. - Add your user to the
dialoutgroup, then log out and back in.
Other chips that look the same
CH9102 comes from the same maker and has the USB ID 1a86:55d4. The macOS driver above covers it. CP2102 comes from Silicon Labs, its driver is linked on the How it works page.
Next step
When the port shows up, open a project and press Flash. If the board still does not connect, the How it works page lists the common causes, and ESP32-CAM has its own page.
