The Research And Application Based On Capacitive Touch Key System

Along with the development of electronic science and technology, capacitive touch key has been widely applied into the design of electronic products. The traditional mechanical circuit keys, due to the complexity of input circuit, wears and tears and the short life span, have gradually lost its popularity. In contrast, the capacitive touch key involves no moving parts and hence simple, reliable, sensitive and accurate, which is a good substitution for the mechanical keys. But, at present the capacitive touch key technology is still in the improvement and polishing stage, and the drift phenomenon has been the biggest weakness in capacitive touch key technology. Some related difficult problems have hindered the further development of this technology, such as sensitivity、 prevents acoustic noise interference and waterproof interference of the capacitive touch key. Therefore, these problems need to be solved and improved urgently.This thesis mainly introduces a touch algorithm of capacitive touch key, which can resistance to acoustic noise interference and waterproof interference well. Through the research of data accuracy、inspection speed、reference voltage、charge or discharge frequency and other parameters of the capacitive touch key to realize the using sensitive、low response time and high precision of capacitive touch key. Meantime, based on the research of capacitive touch key technology, the colorful lights which can be a toy or decoration has been designed. So it can through an example to verify and debug the practical effects of touch key.The colorful lights powered by lithium battery and use the BF6911AS10capacitive touch key controller as the master control. Functions such as on-off, color looping, switching between colors has been accomplished by the multiple touch keys or infrared remote control and software design. The master control by using the GPIO analog PWM output to change the respective duty ratio of RGB LED light to realize color changes function. System uses low power consumption standby mode, it also can charge the lithium battery by the charger.Shown by the research and test results, the use of capacitive touch key has led to low response time、resistance to interference、high precision and it has a certain waterproof capability. It effectively improved and made up for the present shortcomings of capacitive touch key technology. Therefore, the design may make this technology have larger application value and a promising prospect.