Intelligent heat meters toll syetem based on 1-Wire protocol and iButton technology

The design of an intelligent heat meters toll system based on 1-Wire protocol and iButton technology is introduced. The system saves encrypted toll data by data area of DS1991 and communicates between the host and meter by 1-Wire protocol, which is suitable for bad environment of heat meters. In the system a new method is presented for improving the information transmission security, which integrates the DS1991(MultiKey iButton) key technology and simple DES (Data Encryption Standard)algorithm to encrypt important data.