The Stereo Scheme Development With Touch Key Based On The I/O Port Of MCU

The development of Touch Key has been developed for many years,it didn’t widely used in electronic equipment in recent years until the material,skill,the cost,reliability became accessible.The other fields realized the important of touch key after the Apple company developed the MP3player with touch key,and because of the use of touch key in Iphone,touch key became famous in the filed of mobile phone.Besides,touch key is also widely used in home appliance because of its beautiful user interface.At present almost all the touch solution are using a delicated touch IC communicating with the master control chip.Thus,lead to high developing cost.This method occupies interface resource of the main control chip,and it alse can’t be flexible during the development.This topic puts forward a capacitive touch solution by the GPIO of MCU,based on the defection of the special touch IC.Any GPIO of master control chip can realize the touch function by communicating with the RC oscillation circuit. It’s flexible, easy to come up,easy to use.Compare with the traditional capacitive touch dedicated IC,the method has the absolute price advantage.It’s a great break through in the field of capacitive touch.Capacitive touch is applied to the sound development scheme in this paper,it used as a touch button,adjusting the volume of music. Touch key has been successful applied to stereo,because of its flexible response,by hardware design and software optimization.