4*4矩阵键盘扫描 请不要重复上传同一源码，-4* 4 matrix keyboard scanning Do not duplicate upload the same source, in order to open the account owners after passing the examination. If you do not want to upload the source code, you can become a VIP member] access to the account if the other members to download the source code once you upload your available downloads will increase. For more see [Help Help]