A VCP driver for most FTDI USB to serial converters is provided as part of the kernel in OS X 10.9 and later. OS X loads this driver (AppleUSBFTDI.kext) when a device with standard FTDI vendor and product identifiers is connected. To use FTDI's own VCP instead, or to use D2XX programs, AppleUSBFTDI must be disabled, unloaded or blocked, as follows.
Note: this method works only on 10.9 Mavericks and 10.10 Yosemite.
Start a terminal session (Go > Applications > Utilities > Terminal) and copy/paste the following text to
the command prompt:
cd /System/Library/Extensions/IOUSBFamily.kext/Contents/Plugins sudo mv AppleUSBFTDI.kext AppleUSBFTDI.disabled sudo touch /System/Library/Extensionsthen reboot.
cd /System/Library/Extensions/IOUSBFamily.kext/Contents/Plugins sudo mv AppleUSBFTDI.disabled AppleUSBFTDI.kext sudo touch /System/Library/Extensionsthen reboot.
Note: this method works on all versions of OS X.
It is possible to unload Apple's VCP for the current session, i.e. until the next reboot:
sudo kextunload -b com.apple.driver.AppleUSBFTDI(If a warning message indicates that the kext can't be unloaded, then reboot and retry the above command.) To reload:
sudo kextload -b com.apple.driver.AppleUSBFTDIThe kextunload and kextload commands can be run in any directory.
Note: this is the only non-temporary method which works on 10.11 El Capitan.
FTDI provides a signed kernel extension (D2xxHelper.kext) which contains no code but acts to prevent
OS X from matching an FTDI chip (with standard vendor and product identifiers) with a VCP driver, either
Apple's or FTDI's. This leaves the device unclaimed, and available for D2XX programs only.
1. Disconnect all FTDI devices.
2. Download and run the D2xxHelper installer from https://www.ftdichip.com/Drivers/D2XX.htm
3. Reboot.
4. Reconnect the FTDI devices.