To avoid the tedious task of collecting water usage data by go user's home _ water meters that are equipped with wireless communication modules are now being put into use, in this talk we will take a water meter _which is using Lora wireless protocol_ as an example to analyze the security and privacy risks of this kind of meters_we will explain how to reverse engineer and analyze both the firmware and the hardware of a water meter system, we will be talking about its security risks from multiple perspectives , physical, data link, and sensors. Do notice that LORA is not only used in water meter ,it is being used in a lot of IoT scenarios_so the methods we employed to analyze LORA in this talk are also useful when you do tests of other LORA based systems .