This is an image of the CTIA earphone pin out configuration for android,iPhone etc earphones. this earphone pin out is not the same for old Nokia earphones because they use OMTP standards configuration for their earphone. but it is a simple fix just interchange the mic and ground pins if you need support OMTP earphones.
- Android phones,iPhone and most new age phones use CTIA earphones now
- Old Nokia and old devices used OMTP Earphones.
- New Nokia phones use CTIA configuration
- Just interchanging the mic and ground pins enables you support OMTP earphones.
The Pin Out Diagram Image