Had a problem on OS X Yosemite with CH340G chip. Installed the official driver first - http://www.wch.cn/downloads.php?name=pro&proid=178. This didn't work, so I tried to manually load the installed kext and noticed this error in the console:20/10/2014 00:43:28.492 com.apple.kextd: ERROR: invalid signature for wch.usb.usb, will not loadAfter a big of googling found this article - http://www.cindori.org/enabling-trim-on-os-x-yosemite/Just to summarise. On Yosemite:1. install the driver2. Run this:Code: [Select]sudo nvram boot-args="kext-dev-mode=1"3. Restart
sudo nvram boot-args="kext-dev-mode=1"
SIMPLY FOLLOW THESE ON WINDOWS-7-> Download http://www.wch.cn/downloads.php?name=pro&proid=5 and unrar (CH341SER\)-> DISCONNECT USB CABLE OF BOARD-> RUN \CH341SER\setup.exe-> CONNECT USB CABLEHere You Go...
DCcduino MEGA 2560 with WIN7_64 ... I tried installing CH341SER.EXE but still does not recognize the device ...
Where did you get the download from?
Well that is the correct place though you can also change the end of the link to 65 for a slightly different package.What happens in device manager when you connect the device?
Ok, and presumably it goes away when it is unplugged?Download the zip file version of the driver, unzip and then update the driver, point it at the extracted zip file and see if that helps.