How to Install CH340 Drivers

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Introduction

In this tutorial, we'll show you how to install CH340 drivers on multiple operating systems if you need. The driver should automatically install on most operating systems. However, there is a wide range of operating systems out there. You may need to install drivers the first time you connect the chip to your computer's USB port or when there are operating system updates.

CH340 Highlighted and Closeup

Required Materials

Depending on your application, the CH340 may be populated on a breakout or development board. Here are a few boards that use this particular USB-to-serial converter.

SparkFun RedBoard Artemis

SparkFun RedBoard Artemis

DEV-15444
$19.95
SparkFun RedBoard Artemis Nano

SparkFun RedBoard Artemis Nano

DEV-15443
$14.95
SparkFun RedBoard Artemis ATP

SparkFun RedBoard Artemis ATP

DEV-15442
$24.95
SparkFun RedBoard Qwiic

SparkFun RedBoard Qwiic

DEV-15123
$19.95
4
SparkFun Serial Basic Breakout - CH340C and USB-C

SparkFun Serial Basic Breakout - CH340C and USB-C

DEV-15096
$8.95
2
SparkFun Serial Basic Breakout - CH340G

SparkFun Serial Basic Breakout - CH340G

DEV-14050
$7.95
5
SparkFun Servo pHAT for Raspberry Pi

SparkFun Servo pHAT for Raspberry Pi

DEV-15316
$10.95
1

Accessories

You'll also need the correct USB cable to connect the board to your computer. You may need a jumper wires and a breadboard for prototyping.

Jumper Wires Premium 6" M/M Pack of 10

Jumper Wires Premium 6" M/M Pack of 10

PRT-08431
$3.95
2
USB 3.1 Cable A to C - 3 Foot

USB 3.1 Cable A to C - 3 Foot

CAB-14743
$4.95
2
SparkFun Traveler microB Cable - 1m

SparkFun Traveler microB Cable - 1m

CAB-14741
$3.95

Suggested Reading

Before you begin this tutorial, you should have the Arduino IDE installed on your computer. Check out our Installing Arduino tutorial for a step by step guide.

Serial Communication

Asynchronous serial communication concepts: packets, signal levels, baud rates, UARTs and more!

Connector Basics

Connectors are a major source of confusion for people just beginning electronics. The number of different options, terms, and names of connectors can make selecting one, or finding the one you need, daunting. This article will help you get a jump on the world of connectors.

What is an Arduino?

What is this 'Arduino' thing anyway?

Logic Levels

Learn the difference between 3.3V and 5V devices and logic levels.

Serial Terminal Basics

This tutorial will show you how to communicate with your serial devices using a variety of terminal emulator applications.

Alright, let's get to work! You can visit the next section to learn more about the CH340 and why you need the drivers, or you can skip straight to the operating system of your choice!

Meet the CH340

There are a few variants of the CH340. The CH340G requires an external crystal oscillator to function while the CH340C includes a built-in crystal oscillator. However, both function in the same fashion - they convert USB data for a serial UART and vice versa!

CH340G Highlighted CH340C Highlighted
CH340G CH340C

The CH340 is also populated on development boards such as the RedBoard Qwiic to upload code using the Arduino IDE.

RedBoard Qwiic w/ CH340 Highlighted

Drivers (If You Need Them)

The CH340 has been tested on:

  • Windows 7/10
  • Mac OSX
    • v10.10.5 (Yosemite)
    • v10.11.6 (El Capitan)
    • v10.13.0 (High Sierra)
    • v10.14.5 (Mojave)
  • Linux
    • Raspbian Stretch (11-13-2018 release) for the Raspberry Pi
    • Raspbian Buster (2019-07-10 release) for the Raspberry Pi
    • Ubuntu v18.04.2, 64-bit

These operating systems have the CDC drivers pre-installed, which means you shouldn't need to install any extra software. However, there are a wide range of operating systems out there, so if you run into driver problems, you can get the archived drivers linked below:

The CH340 is made by WCH. You can find the latest version of their drivers here, but most of their pages are in Mandarin. If you use a Chrome web browser, you should have the option to have the web page translated.

Updating Drivers

If you have the older CH340 drivers installed, you may need to update them. Below are the instructions for doing so on each of the tested operating systems.

Windows 7/10

Note for Educators: You will need to obtain administrative privileges from your network or IT administrator in order to install these drivers. Make sure to test the drivers before class and set aside some time with students in the classroom when installing the drivers.

Download and run the executable.

Click the "Uninstall" button first. Then click on the "Install" button.

Win 10 Installation Screenshot
Windows CH340 Driver Installation


Driver Verification for Windows

To verify that your driver is working, you should see a difference in the following pictures after plugging the CH340 to a USB port.

Device Manager

To check that the CH340 enumerates to a COM port, you can open the device manager. You can click the Start or (Windows) button and type "device manager to quickly search for the application.

searching for device manager

Using the search on Windows 10 to look for the device manager.

After opening the device manager, you will need to open the Ports (COM & LPT) tree. The CH340 should show up as USB-SERIAL CH340 (COM##). Depending on your computer, the COM port may show up as a different number.

CH340 in the Device Manager

Screenshot of Window 10 Device Manager with a CH340 displayed on COM123. Click to enlarge.

Arduino IDE

Alternatively, if you have the Arduino IDE installed, you should also see a change in the number of available COM Ports (you may need to restart the Arduino IDE for the board to populate). Without the CH340 connected to your computer, click on Tools > Port. Take note of the Serial Ports available.

Arduino IDE COM Ports

Connect the CH340 to your computer's USB port. Click on somewhere else on the screen for the menu to refresh itself. Then head back to the menu by clicking on Tools > Port. A new COM port should pop up. By process of elimination, the CH340 should have enumerated to the new COM port! Feel free to click on the COM port to select if you are uploading code to a microcontroller. Depending on your computer, the COM port may show a different number.

Arduino IDE COM Ports CH340

Serial Loop Back Test

You can also verify if the USB-to-serial converter is working by doing a serial loop back test or echo test. If you are using the breakout board, you can add a jumper between the Tx and Rx to try and echo a character in a terminal program. For more information, try checking out the Hardware Test for the serial basic hookup guide.

Serial Loop Back Test

Mac OSX

Note for Educators: You will need to obtain administrative privileges from your network or IT administrator in order to install these drivers. Make sure to test the drivers before class and set aside some time with students in the classroom when installing the drivers.

Open the Terminal program by selecting Go > Applications.

Applications Folder

Select and open the Terminal program under Applications > Utilities > Terminal.

Open the Terminal Window

Note: You can also search with Spotlight by pressing (Command) + space bar (Space Bar). Then type "Terminal" and double-click the search result.

If you are still unsure of how to access the Terminal, watch this video or read this Apple support article.

You'll need to move to the directory where the *.kext files are stored.

  • For Mac OSX v10.9+, you will need to use this command:

    language:bash
    cd /Library/Extensions
    
  • For Mac OSX v10.8 and below, you will need to use this command:

    language:bash
    cd /System/Library/Extensions
    

In this case, we will be using Mac OSX v10.13, so we will need to use the first command.

change directory to where the drivers are located

To check to see if the CH340 driver is in the correct path, use the following command to list the contents of the folder.

language:bash
ls

To look for CH340 driver files (i.e. usb.kext or usbserial.kext) in the path, you could use the following command.

language:bash
ls | grep usb

You should see something similar to the output below after using the commands.

KEXT file path

If you have found the file in the path, you will need to run each of the following commands in the CLI/Terminal to remove old CH340 drivers. In this case, there was only the usbserial.kext file but it does not hurt to run both commands. Make sure to have administrative privileges to ensure that the drivers are removed.

language:bash
sudo rm -rf /Library/Extensions/usb.kext
sudo rm -rf /Library/Extensions/usbserial.kext

Check if the old drivers were removed in the paths by using the ls command with your respective OS version. You will notice that the *.kext file is removed from the respective paths. In this case, the usbserial.kext was removed from Mac OSX High Sierra.

language:bash
ls

CH340 Drivers Removed

Download and extract the folder.

Then, open the "*.pkg" file from the unzipped folder and follow the instructions. You'll need to restart your computer for the changes to take effect.

Mac OSX Installation Screenshot

Mac OSX CH340 Driver Installation File


Driver Verification for Macs

To verify that your driver is working, you should see a difference in the following pictures after plugging the CH340 to a USB port.

Command Line

Open the Terminal by heading to Applications > Utilities > Terminal if the program is not open yet.

Open Terminal Program

Then run the following command:

language:bash
ls /dev/cu* 

A list of devices connected to your Mac's COM ports will be displayed as a result. Assuming that the CH340 is not connected to your computer, you should see something similar to the image below.

List of Devices Connected

Connect the CH340 to one of your Mac's COM ports. Check for the following changes (your board may show up under a different device name). The CH340 should show up as /dev/cu.wchusbserial*****. Depending on your computer, the COM port may show up as a different number.

List of Devices Connected with the CH340

Screenshot of Mac OSX terminal with CH340 on cu.wchusbserialfd1410. Click to enlarge.

Arduino IDE

Alternatively, if you have the Arduino IDE installed, you should also see a change in the number of available COM Ports (you may need to restart the Arduino IDE for the board to populate). Without the CH340 connected to your computer, click on Tools > Port. Take note of the Serial Ports available.

Available Serial Ports on Arduino IDE

Connect the CH340 to your computer's USB port. Click on somewhere else on the screen for the menu to refresh itself. Then head back to the menu by clicking on Tools > Port. A new COM port should pop up. By process of elimination, the CH340 should have enumerated to the new COM port! Feel free to click on the COM port to select if you are uploading code to a microcontroller. Depending on your computer, the COM port may show a different number.

Available Serial Ports  w/ CH340 on Arduino IDE

Serial Loop Back Test

You can also verify if the USB-to-serial converter is working by doing a serial loop back test or echo test. If you are using the breakout board, you can add a jumper between the Tx and Rx to try and echo a character in a terminal program. For more information, try checking out the Hardware Test for the serial basic hookup guide.

Serial Loop Back Test

Linux

Note for Educators: You will need to obtain administrative privileges from your network or IT administrator in order to install these drivers. Make sure to test the drivers before class and set aside some time with students in the classroom when installing the drivers.

Raspbian for Raspberry Pi

Run the following commands in the CLI/Terminal when using Raspbian on a Raspberry Pi. After updating, the latest CH340 should be installed!

language:bash
sudo apt-get update
sudo apt-get upgrade

Other Linux Distributions

Here is a downloadable *.ZIP of standard CH340 drivers for Linux.

There are some reported cases of serial communication failure when using the factory drivers in Linux. If you encounter this problem, you can try installing patched drivers as explained in this forum post. Here are the steps (to run in the command line):

  • Plug and unplug your CH340 device from the USB port
  • Type dmesg to see what has happened
    • The expected output (shows "ch341") should have the following in the recent log:
[  xxx] ch341-uart ttyUSB0: ch341-uart converter now disconnected from ttyUSB0
[  xxx] ch341 3-2:1.0: device disconnected
  • Download the patched drivers repository and unzip the files


  • cd into the directory where the files are saved
  • make clean
  • make
  • sudo make load
  • sudo rmmod ch341 to uninstall the broken driver
  • lsmod | grep ch34 to list what modules are currently installed
  • Plug and unplug your CH340 device again on the USB port
  • dmesg
    • Expected output (should show "ch34x" now):
[  xxx] ch34x ttyUSB0: ch34x converter now disconnected from ttyUSB0
[  xxx] ch34x 3-2:1.0: device disconnected

Depending on your root permissions, you may need to configure the serial port with the following two commands. Make sure to adjust the $username with respect to the user ID that is currently logged in.

language:bash
sudo usermod -a -G dialout $username 
sudo chmod a+rw /dev/ttyUSB0

Driver Verification for Linux

Command Line

Plug the CH340 back to your computer's USB port. Then run the following command in the CLI/Terminal on any Linux distribution. Check for the following changes (your board may show up under a different device name).

language:bash
ls /dev/ttyUSB*

The serial port that CH340 is connected to should pop up as a result.

Raspbian CLI Command Entry
Screenshot of Raspberry Pi CLI with the CH340 on ttyUSB0. Click to enlarge

Arduino IDE

Alternatively, if you have the Arduino IDE installed, you should also see a change in the number of available COM Ports (you may need to restart the Arduino IDE for the board to populate). Without the CH340 connected to your computer, click on Tools > Port. Depending on the Linux flavor that you have, the Ports may not open to display any serial ports. Take note of the Serial Ports available if it opens up.

Linux Ubuntu Arduino COM Ports

Connect the CH340 to your computer's USB port. Click on somewhere else on the screen for the menu to refresh itself. Then head back to the menu by clicking on Tools > Port. A new COM port should pop up. By process of elimination, the CH340 should have enumerated to the new COM port! Feel free to click on the COM port to select if you are uploading code to a microcontroller. Depending on your computer, the COM port may show a different number.

Linux Ubuntu Arduino COM Ports CH340

Serial Loop Back Test

You can also verify if the USB-to-serial converter is working by doing a serial loop back test or echo test. If you are using the breakout board, you can add a jumper between the Tx and Rx to try and echo a character in a terminal program. For more information, try checking out the Hardware Test for the serial basic hookup guide.

Serial Loop Back Test

Troubleshooting

COM Port is Not Showing Up as CH340 Windows

We have had a few reports on Windows 10 where the driver will automatically install and the board will show up under a new COM port as USB-Serial CH340, but with a different device name. However, the board cannot be accessed on the Arduino IDE. Others have had issues where the installation process hangs.

Based on the customer experiences, this might be specific to the manufacturer and are usually isolated cases. Users seem to be able to eventually get the board recognized by a combination of giving the computer time to finish the install (close to 20 min), plugging the board back in multiple times, reinstalling the drivers, and/or resetting the computer multiple times (repeat both steps).

COM Port Not Available Windows, Mac, and Linux

If you installed the drivers for the CH340 on your computer but have issues connecting via serial terminal or uploading code using the Arduino IDE, there may be an issue with your user settings preventing you from using the CH340. You may receive an avrdude: ser_open(): can't open device error similar to the output shown below.

language:bash
avrdude: ser_open(): can't open device "/dev/ttyUSB0": No such file or directory

In this case, the error appeared on a Linux when trying to upload code due to the drivers not being installed and the root permissions.

Arduino ser_open() error

Make sure to check your configuration settings and ensure that the serial port for the CH340 is enabled for your OS. You may also need to reinstall the drivers for your operating system.

USB Cable Windows, Mac, and Linux

Certain USB cables are for power only and may not have the data lines available. Try checking your USB cable and ensure that the data lines are intact.

Issues Uploading at Fast Baud Rates

If you are uploading to certain boards like the Apollo3 on the Artemis development boards with fast baud rates, there are some platforms (Linux flavors) where the standard CH340 USB to serial drivers don't operate well at speeds higher than 115200. So if you run into upload problems, consider reducing the upload speed. For more information about upload issues, see this forum post and consider upgrading with these drivers for Mac OSX or these for Linux.

Resources and Going Further

Now that you've successfully got your CH340 up and running, it's time to incorporate it into your own project!

USB-to-serial converters like the CH340 are great for uploading code to a microcontroller or viewing data from a GPS on a serial terminal. Check out these tutorials to dive even deeper into the world of microcontrollers or send serial data to your computer with a GPS!

Serial Terminal Basics

This tutorial will show you how to communicate with your serial devices using a variety of terminal emulator applications.

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SparkFun Inventor's Kit Experiment Guide - v4.1

The SparkFun Inventor's Kit (SIK) Experiment Guide contains all of the information needed to build all five projects, encompassing 16 circuits, in the latest version of the kit, v4.1.

Or check out these blog posts.