在官方手册上有这么两句话：Output data from the DS18B20 is valid for 15μs after the falling edge that initiated the read time slot. Therefore, the master must release the bus and then sample the bus state within 15μs from the start of the slot.
但技术资源，应用笔记126 用软件实现1-Wire®通信中，却是在15us后才采样的？
