user11537: I have an Arduino Nano and I’m trying to use it with Mac OS Yosemite (10.10). However, I’m having issues with the data transfer between the computer and the device. The Arduino is powered (LED is illuminated), however, I can’t upload anything to it. The serial port is not recognised and after installing a multitude of drivers, nothing seems to work.
Is there a specific driver or process I need to follow to enable data transfer?

user16074: From this blogpost you can download signed macOS driver for CH340. Works fine on Sierra 10.12!

user651: Setting kext-dev-mode=1 allows unsigned kernel extensions to load, which is not recommended, as it lowers OS X security.
Instead, try the signed 64-bit kernel extension from FTDI here: http://www.ftdichip.com/Drivers/VCP.htm , version 2.3, which does require changing OS security permissions.

11537: <p>I have an Arduino Nano and I’m trying to use it with Mac OS Yosemite (10.10). However, I’m having issues with the data transfer between the computer and the device. The Arduino is powered (LED is illuminated), however, I can’t upload anything to it. The serial port is not recognised and after installing a multitude of drivers, nothing seems to work.</p>

<p>Is there a specific driver or process I need to follow to enable data transfer?</p>
 16074: <p>From <a href="https://blog.sengotta.net/signed-mac-os-driver-for-winchiphead-ch340-serial-bridge/" rel="nofollow noreferrer">this blogpost</a> you can <a href="http://blog.sengotta.net/wp-content/uploads/2015/11/CH34x_Install_V1.3.zip" rel="nofollow noreferrer">download</a> <strong>signed</strong> macOS driver for CH340. Works fine on Sierra 10.12!</p>
 651: <p>Setting kext-dev-mode=1 allows unsigned kernel extensions to load, which is not recommended, as it lowers OS X security.</p>

<p>Instead, try the signed 64-bit kernel extension from FTDI here: <a href="http://www.ftdichip.com/Drivers/VCP.htm" rel="nofollow">http://www.ftdichip.com/Drivers/VCP.htm</a> , version 2.3, which does require changing OS security permissions.</p>
