I'm trying to connect to my Sparkfun Redboard (Arduino UNO compatible) on Mac OS X 10.12.3 (Sierra). The board comes with a USB mini to USB A FTDI cable. The board lights up and gets power over USB, but I don't see the right USB serial port in the Arduino IDE (I only see the Bluetooth port).

I've installed the VCP FTDI drivers v2.3 to no avail. When that didn't work, I also installed the CH340 CH341 drivers (but I doubt I need those). Rebooting the computer didn't help either.

I can only load the FTDI VCP v2.3 drivers using an explicit command sudo kextload /Library/Extensions/FTDIUSBSerialDriver.kext/. When I run kextstat | grep FTDI, I get:

 155    0 0xffffff7f83892000 0x7000     0x7000     com.FTDI.driver.FTDIUSBSerialDriver (2.3) ECC3AF36-431D-370D-86F2-5237785E9CF8 <127 41 5 4 3 1>

But it still doesn't show up in the Arduino IDE.

I've heard that Apple's own USB FTDI drivers (AppleUSBFTDI) could cause problems, but it seems these are never loaded. If I try to unload the Apple FTDI driver (sudo kextunload –b com.apple.driver.AppleUSBFTDI), I get the following:

(kernel) Kext com.apple.driver.AppleUSBFTDI not found for unload request.

Failed to unload com.apple.driver.AppleUSBFTDI - (libkern/kext) not found.

Any tips are welcome. Thanks!


I'm using MacOS Sierra and an Arduino Pro Mini (from Sparkfun) with a breakout USB-to-UART board that uses an FTDI FT232 chip. I'm using the default Apple FTDI drivers (the ones that are bundled with Sierra) and I'm having no problems whatsoever.

Some people have reported problems using the manufacturer (FTDI) drivers that they had already installed after upgrading to Sierra. Some of them solved it by uninstalling the conflicting drivers and relying on the default Apple FTDI drivers uninstalling the conflicting drivers and relying on the default Apple FTDI drivers instead. It's worth a try.

OTOH, the CG340 driver doesn't currently work under Mac OS Sierra. Fortunately, Adrian Mihalko patched the driver and made it available at GitHub, along with some troubleshooting instructions.


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