Application of sensor in notebook anti-theft device

Summary

In recent years, this situation has occurred when personal valuables such as notebooks have been stolen, and a low-power wireless anti-theft device based on an acceleration sensor has been designed. It is proposed to build the simplest wireless sensor network through only 2 nodes, transmit PC mobile information, notify the owner to react quickly and avoid the loss of the notebook. Through the hardware circuit design and software programming programming, the entire network is driven, and the expected alarm effect is achieved through experimental tests. The utility model solves the defects that the general anti-theft device is expensive, the system is complicated, the volume is large, and the delay is long.

With the continuous development of the social economy, the popularity of notebooks has become more and more popular, and the security and theft of PCs have become increasingly prominent. It is inconvenient to carry a notebook with you on some occasions. For example, when traveling by train, when the owner goes to the bathroom, how to prevent and prevent the thief from stealing the notebook at this time is an urgent problem to be solved. Today's widely used car anti-theft technology is very mature, but relatively high cost, and no need to consider power problems, and PC anti-theft must solve these problems; also small size, can be installed on the PC at any time. Here, it is proposed to use only two nodes based on the Simplici TI communication protocol (with accelerometer) for point-to-point communication to complete the anti-theft function.

1 overall plan

The system design is very simple. Generally speaking, the total length of the train carriage is 26.6 m, and the communication distance of the wireless sensor net2works (WSN) is between tens of meters and several hundred meters, generally 30 m, so that one node can completely cover the entire compartment. There are only 2 nodes in the system (without PC assistance): Node 1 acts as the sender and Node 2 acts as the receiver, making up the simplest network without jumping. The structure of the system is simple, so that the transmission delay is very small, and it is suitable for the application mentioned above.

1.1 Program implementation

The train compartment is divided into two zones: Zone 1 is the location of the PC, that is, the seat of the owner. When the person does not leave, Zone 1 is safe; Zone 2 is the rest of the compartment where Zone 1 is removed. When the owner enters Zone 2 due to a problem, Zone 1 will become a blind spot and the PC will become unsafe. The solution implementation steps are shown in Figure 1.

Implementation steps:

(1) Thief B attempts to move the computer;

(2) The movement of the computer causes the node 1 fixed above to move;

(3) The acceleration sensor on node 1 acquires the speed information, and the RF chip on node 1 transmits the speed information;

(4) Node 2 receives the information, determines whether the speed PC belongs to the abnormal movement by a predetermined program, and if so, triggers the buzzer to alarm, and vice versa;

(5) Master A quickly returns to his seat after hearing the alarm to avoid PC loss.