此软件用QT编写。可以检测身份正所在地，以级判断男女。其调用一个叫info.cute的数据文件来实现查找地址信息。-check ID card no.

400KHz is max freq for card ID etc. Use that as min card clock. We need to know the min to enable static calculation of max BCM2835_SDHCI_WRITE_DELAY.