The study on coal mine using the Bluetooth wireless transmission

The safety of coal mine is an important link in coal mine production,gas disaster is the most harmful for the safety of coal mine production. During the process of mine development, it is very important to measure the gas concentration in mines. For the present of situation of gas concentration monitoring system, this paper proposes a Bluetooth-based coal mine gas concentration monitoring system design, describes the ideas and specific methods software and hardware design. As a standard of unified global short-range wireless communication, Bluetooth technology is to establish a common low-power, low-cost wireless air interface and controlling software opening system. This paper describes the development background, technical features and the structure of the protocol stack of Bluetooth technology, and proposed the solutions of the Bluetooth host controller interface (HCI) wireless communication for the complexity of its development. At the same time, the system uses CAN bus technology maturely, has realized the combination of wired and wireless data transmission system. This paper presents the complete block diagram of the system and the various parts of the circuit diagram, describes how to use micro controllers and Bluetooth module to build system, introduced the principle used in the device. Analyzed the solution of the theoretical basis of the Bluetooth HCI protocol and the HCI UART transport layer of instruction in detail. Parsing a process of using the HCI protocol in Bluetooth device initialization, querying other equipment, establishing the link, data transmission and disconnect the link, and describe the flow chart of software development in Bluetooth main transceiver unit. Meanwhile, this paper describes the hardware and software design of CAN nodes. This article presents some debugging information to prove that the Bluetooth technology can convenient replacement cable interface in this system, provide a new way of data transmission for security and monit- ring of coal mine.