ADS7846/7843芯片 适合用在4线制触摸屏，它通过标准SPI协议和CPU通信，操作简单，精度高，当触摸屏被按下时（即有触摸事件发生）则ADS7846向CPU发中断请求，CPU接到请求后，应延时一下再响应其请求，目的是为了消除抖动使得采样更准确-ADS7846/7843 chip suitable for use in the 4-wire Touchscreen, SPI through standard protocols and CPU communication, simple operation, high accuracy, When the touch screen is pressed (that is, touching incident) ADS7846 to the CPU interrupt request, CPU upon request, should be about responding to delay its request, the purpose of eliminating jitter make more accurate sampling