Calculate Resistance and Voltage Drop on the iPhone
If you use an SDR-14 or SDR-IQ with Mac OS X 10.10 or 10.11, you may run into issues due to Apple’s built in FTDI USB driver, which prevents the FTDI D2XX library from accessing it. Previously you could just unload the driver when you wanted to run your SDR software, but Mac OS X 10.11 El Capitan compounds the problem by making that impossible under normal conditions. This is part of Apple’s System Integrity Protection (SIP), also known as “rootless” mode.
SIP prevents any user, even those with system administrator (“root”) privileges, modifying a number of operating system directories and files.
Unfortunately this also prevents you from stopping the use of Apple’s built in FTDI driver, which you must do in order to run applications that use FTDI’s D2XX library. In our case, to stop the use of Apple’s built in driver, we need to install a codeless kernel extension (kext). This extension claims priority over Apple’s built in driver, but doesn’t actually do anything, leaving the device available for the D2XX library to access it. It should also work under 10.9 Mavericks, making it unnecessary to unload the Apple kext each time you want to use your SDR.
Before continuing, please note that you perform all these steps at your own risk. Guaranteed to blow up your Mac. blah blah blah.
To disable SIP on Mac OS X 10.11 El Capitan:
1. Restart your Mac.
2. As soon as you hear the startup chime, hold down Command-R and keep it held down until you see the Apple icon and a progress bar.
3. After you have booted into Recovery Mode, select Terminal from the Utilities menu.
4. At the prompt type:
5. You should see a message saying that SIP was disabled.
6. Select Restart from the Apple menu.
If you’re running Mac OS X 10.10 Yosemite, you can disable kernel extension code signing:
1. Open the Terminal application
2. Type the following:
3. Press return and enter your administrator password
The next step is to install a codeless kernel extension. It won’t actually do anything, other then prevent the built in Apple FTDI USB driver from being used with the SDR. You can download unsigned codeless kernel extension (kext) files, along with a copy of the SDR-xx Server app, here: http://radiohobbyist.org/blog/mypics/SDR_14_IQ_Mac_OSX.zip
Under El Capitan and Yosemite, it needs to be installed in /Library/Extensions./
If you need to load an unsigned kext in Mavericks, it should be in /System/Library/Extensions/
For El Capitan and Yosemite, we would type the following at the Terminal prompt (assuming you’re in the directory containing the kext file):
sudo cp -r SDR14USBFTDICodelessKext.kext /Library/Extensions
sudo cp -r SDR14USBFTDICodelessKext.kext /System/Library/Extensions
For an SDR-IQ, you would use the file SDRIQUSBFTDICodelessKext.kext instead, as it has a different USB PID (Product ID).
You should then be able to plug in your SDR-14 or SDR-IQ, and see it is found by the SDR-xx Server app. Note that to run SDR-XX Server, libftd2xx.1.0.4.dylib needs to be installed in /usr/local/lib
cp libftd2xx.1.0.4.dylib /usr/local/lib
You can then run SdrDx or another SDR app that expects a networked SDR.
I can’t provide individual assistance with getting this to work, but feel free to post questions as comments, and maybe I or someone else can provide an answer.