28335中冠以如何利用3x3键盘的例程，可以参考一下，开发板带的，但是是根据TI官网例程改编的，通用性挺好-28335 in how to use the 3x3 keyboard dubbed routines, you can refer to, the development of the strip, but it is based on TI' s official website routines adaptation, good versatility