They have ethernet cross over cables, serial crossover cables, now we finally have an audio crossover cable!
This "crossover" board kit turns your HamShield into a virtual headset for you phone! It can interface to any iPhone, Android, Mac or most PC's (with a dual headset/headphone jack). The circuit also level shifts the audio to ensure that it sounds just right.
Perfect for interfacing to smart phone and PC applications.
Board features simple to solder throughhole components and requries some basic assembly.
You can also use the TRRS Crossover Cable Device Kit for other applications, such as connecting the microphone and speaker of two phones or PCs together.
Here is a video on assembling your TRRS Crossover Kit:
(The HamShield pictured is not included and is used as a reference)