Undefined symbols for architecture armv7, common fixes not resolving

Question

I know this is a really common question, and I'll list what I've tried here but I've been tearing my hair out trying to figure out why I can't import a third party SDK in Xcode. Common fixes suggested in other threads has not worked.

I'm getting the error output listed below, and I have tried:

1. Adding the correct libraries in the Link Binary With Libraries section of the Build Phases
   

2. I copied the DoubleControlSDK.framework file to the default Library Search Path in Build Settings
   

3. I added the .m files to Build Phases > Compile Sources
   

4. I yelled really loud at the screen, and threatened to disassemble the computer if it didn't link the damn files.
   

No idea what else to try. I'm hoping maybe there's something in the error output that I'm not noticing. Need to go outside for a while

Undefined symbols for architecture armv7:
  "_OBJC_CLASS_$_EASession", referenced from:
  objc-class-ref in DoubleControlSDK
"_EAAccessoryDidConnectNotification", referenced from:
  -[DRDouble init] in DoubleControlSDK
 "_OBJC_CLASS_$_EAAccessoryManager", referenced from:
  objc-class-ref in DoubleControlSDK
"_OBJC_CLASS_$_ZBarReaderView", referenced from:
  objc-class-ref in EmbedReaderAppDelegate.o
  ld: symbol(s) not found for architecture armv7
clang: error: linker command failed with exit code 1 (use -v to see invocation)

Edit:

Answer 1

You need to add the libraries that the third-party library also depends on. One is Apple's `ExternalAccessory.framework". The other seems to be from yet another third-party item called ZBarReaderView.

http://zbar.sourceforge.net/iphone/sdkdoc/ZBarReaderView.html