CH340 and CH341 USB-Serial driver

Latest driver

What is CH340?

CH340 and CH341 are USB-to-serial (UART) bridge chips made by WCH (Nanjing Qinheng Microelectronics). They are the cheapest way to add a COM port over USB, so you find them on Arduino Uno and Nano clones, ESP8266 NodeMCU and many ESP32 boards, USB-TTL programming adapters, 3D printers and GPS modules. In Device Manager the chip appears as USB\VID_1A86&PID_7523 (CH340) or USB\VID_1A86&PID_5523 (CH341 in serial mode).

Do I need to install it?

Windows 10 and 11 usually download the CH340 driver from Windows Update automatically when the board is connected to the internet-connected PC. Install it manually if the board shows up as USB2.0-Serial under Other devices with a yellow sign, or if no USB-SERIAL CH340 (COMx) port appears under Ports (COM & LPT).

How to check that it works

1. Connect the board and open Device Manager → Ports (COM & LPT).
2. Note the COM number of USB-SERIAL CH340 and select the same port in the Arduino IDE, PlatformIO, esptool or your terminal program.
3. If uploads fail with “port busy” or “access denied”, close other serial monitors that may hold the port open.

Common problems

• No new device appears at all when you plug the board in — the USB cable is likely charge-only. Try a cable that you know transfers data. See also Unknown USB Device (Device Descriptor Request Failed).
• Code 10 after a driver update — uninstall the device with “Attempt to remove the driver”, reconnect and install the driver from this page.
• Wrong COM port number — you can change it in the port’s Properties → Port Settings → Advanced.

On Linux the chip is supported by the ch341 kernel module and needs no separate driver.

All drivers

Hardware IDs

Compare these IDs with Device Manager → Properties → Details → Hardware Ids of your device (how to find them).