The CH340 chip is used by a number of Arduino compatible boards to provide USB connectivity, you may need to install a driver, don’t panic, it’s easier than falling off a log, and much less painful.

Windows

(Manufacturer’s Chinese Info Link)

The VCPTest program is intended to show how to communicate with an FTDI device from a Windows CE based system using FTDI’s VCP drivers for Windows CE. It sends and receives data through a loopback connector. To download the program with C source code, click click here.
Download FTDI FTD2XX USB Drivers for free. FTDI FTD2XX USB Drivers installs the necessary files in your Windows directory.
For other USB-2920 compatible drivers (older Windows, Windows CE, all Linux / Mac / etc ) go here: FTDI VCP Drivers Page Older MegaSquirt Tuning Software and Utilities Development on these has stopped as of 2016, but the software is still available.
Download a copy of the v2.12.28 FTDI VCP Driver Executable here: Windows FTDI VCP Driver Executable - v2.12.28 (CDM21228Setup.exe) Otherwise, visit FTDI's VCP Drivers page for the latest download of the Windows FTDI Driver executable and clicking on the Window's 'Available as a setup executable' link.

Download the Windows CH340 Driver
Unzip the file
Run the installer which you unzipped
In the Arduino IDE when the CH340 is connected you will see a COM Port in the Tools > Serial Port menu, the COM number for your device may vary depending on your system.

Ftdi Usb Download; Ftdi Usb Driver; Ftdi Usb Serial; Ftdi Usb Drivers Software. MK Registry & USB Fixer v.3.0.1. MK Registry & USB Fixer is a small and very easy to.

Older Windows Driver Version and Instructions

~~Download the Windows CH340 Driver~~
~~Unzip the folder.~~
If you are running a 64Bit Windows: – run the SETUP_64.EXE installer.
If you are running a 32Bit Windows: – run the SETUP_32.EXE installer.
~~If you don’t know, try the 64 bit and if it doesn’t work, the 32 bit.~~
~~In the Arduino IDE when the CH340 is connected you will see a COM Port in the Tools > Serial Port menu, the COM number for your device may vary depending on your system.~~

Macintosh

(Manufacturer’s Chinese Info Link)

The following github has up to day pkg files for 1.3, 1.4 and 1.5 at time of writing, thanks to Joshua Wallis for bringing this to my attention…

Direct Download Links (from the github repo above):

See the github link above for installation instructions if you need them.

Previous macinstosh downloads if the above doesn’t work for you…

~~(V1.3) Download the CH340 Macintosh Signed Driver for Mavericks (10.9), Yosemite (10.10) and El Capitan (10.11) and Sierra (10.12)~~

~~Inside the zip file you will find a PDF and a “pkg” file, short version, double click the pkg file, the PDF has some extra information.~~

~~OSX Sierra (10.12) Note~~

~~A kindly user, Maarten Segers reports~~

Ftdi Driver Download Arduino

~~FYI, the driver documented here WILL crash on OSX Sierra.~~

~~Make sure to use this one instead: https://github.com/MPParsley/ch340g-ch34g-ch34x-mac-os-x-driver~~

~~I can personally not test on MacOS and can not vouch for the above drivers at github, but there you go.~~

Ftdi Drivers Download Free

~~See uninstalling information at the bottom of the page if the driver causes problems for you.~~

~~Here is an older version of the Mac driver, NOT FOR 10.12 Sierra~~

~~(V1.0) Download the CH340 Macintosh Signed Driver for Mavericks (10.9), Yosemite (10.10) and El Capitan (10.11)~~

Linux

Free Ftdi Driver Download

(Manufacturer’s Chinese Info Link)

Drivers are almost certainly built into your Linux kernel already and it will probably just work as soon as you plug it in. If not you can download the Linux CH340 Driver (but I’d recommend just upgrading your Linux install so that you get the “built in” one).

Uninstalling From Macinstosh

Ftdi Driver Download Exe

A couple of Mac users have said “the driver crashes my mac Sierra how do I uninstall”.

Ftdi D2xx Driver Download

Drivers savin. Firstly regards the crash make sure you installed the 1.3 version of the driver, not the old one. You could download it directly from the Manufacturers Website in case they have issued an update since I wrote this page.

Secondly a quick google search reveals that this is how you uninstall:

Open a terminal and type: cd /Library/Extensions/
Verify that the .kext file is present: ls | grep usbserial.kext
Output should be: usbserial.kext
Then type: sudo rm -R usbserial.kext
Verify that the .kext file has been removed: ls | grep usbserial.kext
Output should be empty.
After you should remove the files stored in receipts folder: cd /private/var/db/receipts/
Find the enties: ls | grep usbserial*
Output should be: codebender.cc.ch34xinstaller.usbserial.pkg.bom codebender.cc.ch34xinstaller.usbserial.pkg.plist
Remove each one of the files of the above list: sudo rm -r filename`