Bluetooth Smart Barricade System

Intelligent roadblock system based on bluetooth control technology

With the increase of vehicles, urban traffic problems are becoming more and more prominent. Roadblocks are an essential facility for traffic management. Traditional roadblocks are manually arranged and moved. Staff are in danger of being hit by vehicles. The use of intelligent roadblock systems can avoid being hit by cars. Hazardous, reduce manual labor. With the continuous development of smart cities and smart transportation, my country's research in the field of unmanned vehicles has made great progress. During the testing process, there are still uncontrollable dangers. In the road link, the intelligent roadblock system is adopted to remotely control the transformation of the roadblock formation to prevent danger and protect the personal safety of the participants.

1. Overall design of intelligent roadblock system

Considering the functional requirements and cost control used in the competition, in this design scheme, the intelligent roadblock is mainly divided into two parts: the control unit and the wireless module. A relatively stable remote control design is adopted, and a dedicated remote control is designed as the control terminal. The STM32F103 series single-chip microcomputer is used as the main control unit of the intelligent roadblock and the remote control, and the wireless transmission module adopts the master-slave integrated Bluetooth chip HC-05. Due to the large loss of smart roadblocks in the competition, in order to ensure the loss of the competition, there must be a sufficient number of smart roadblocks. This design realizes cost control on the basis of meeting the functional requirements and quantity requirements of the competition.

1.1 Intelligent roadblock hardware circuit design

From the perspective of mechanical structure, the intelligent roadblock is divided into an upper roadblock and a lower movable wheeled base plate, and the road block and the base plate are fixed together with screws. There are two driving wheels and one driven wheel under the bottom plate, each of which is equipped with a DC motor, and the bottom plate is fixed with a motor drive module L298N, a core control unit STM32, a Bluetooth chip HC-05, and a 7.2V rechargeable lithium battery. The remote control uses STM32 as the main control unit, 4*4 matrix membrane switch as the remote control button, and 5V dry battery as the power supply.

The L298N integrates two high-voltage and high-current full-bridge drivers of the H-bridge, which can drive inductive loads; it adopts standard logic level signal control; it has two enable control terminals, allowing or There is a logic power input terminal for prohibiting the operation of the device, so that the internal logic circuit part can work under low voltage; the detection resistor can be connected externally, and the change can be fed back to the control circuit.

The chip can drive a two-phase stepper motor or a four-phase stepper motor, or two DC motors. The L298N directly drives two DC motors, namely M1 and M2. Pins A and B are connected to 5V, the motor is working at the highest speed, the input signal terminal IN1 is connected to a high level input terminal IN2 is connected to a low level, and the motor M1 is rotating forward. The signal terminal IN1 is connected to a low level, IN2 is connected to a high level, and the motor M1 is reversed. Controlling M2 is the same way.

1.2 Intelligent roadblock software design

In terms of software design, the main control unit we use is STM32, a 16-bit microcontroller with a clock frequency of up to 72MHz and a power consumption of 36mA, which has the advantages of powerful performance and ultra-low power consumption. It meets our design requirements and can stand by for a long time. After testing, it can stand by for 48 hours when not in use. Under continuous testing, it can work continuously for more than one hour, which fully meets our needs. After the power is turned on, the program performs initialization settings, and the smart roadblock works in the standby state. The Bluetooth module has been detecting whether it has received a control signal. After receiving the signal, the smart roadblock Bluetooth module sends the control signal to the smart roadblock control unit. Control the signal to make forward, backward, left turn, right turn actions to realize the movement of intelligent roadblocks and meet the requirements of roadblock formation changes.

1.3 Smart Barrier Bluetooth Design

Bluetooth is a wireless technology standard, which can realize data transmission between fixed equipment and mobile equipment. The HC-05 Bluetooth module used in this design can perform full-duplex communication with the STM32 series single-chip microcomputer main control chip, that is, the two can read and write each other. For example, when sending data from the Bluetooth module, the write terminal (TXD) of HC-05 is connected with the read terminal (RXD) of the MCU main control chip to realize communication; otherwise, the read terminal (RXD) of HC-05 and the MCU main control chip The write terminal (TXD) is connected. When connecting, you need to pay attention to the cross-connection of two pairs of read-write terminals, and the two need to share the same ground (this Bluetooth module has a total of 4 pins on the power terminal, and there is no need to connect them separately).

The remote control and the smart roadblock communicate wirelessly through the Bluetooth module. The Bluetooth on the remote control side is set to the master mode, and the Bluetooth on the smart roadblock side is set to the slave mode. Different passwords are set for the two remote controllers, which can distinguish the two remote controllers from controlling two sets of smart roadblocks. According to the button pressing mode of the control terminal, different numbers of intelligent barriers will respond. After testing, the bluetooth chip we choose can reach an outdoor control distance of 20 meters, which can fully meet our design requirements.

2. Design of the remote control end of the Bluetooth smart roadblock system

In this project, a total of 50 intelligent roadblocks are designed, and each group of 10 is numbered A 0-9, B0-9, C0-9, D0-9, E0-9. The program assigns different numbers to each roadblock The setting enables the smart barricade to discern whether to respond to a control signal. On the track, different numbers of smart roadblocks can be adjusted to realize free formation changes of roadblocks, providing a good competition environment for the China Smart Car Future Challenge.

Considering that the roadblocks are divided into two rows during the competition, we designed two remote controllers to control 25 smart roadblocks respectively, and the two groups correspond to two rows of roadblocks. The 0-9 number keys of the matrix membrane switch correspond to the individual numbered 0-9 intelligent roadblocks; the # key corresponds to the all-select function (25 sets are all selected), and in the all-select mode, the number 0 is selected to correspond to the remote control of the corresponding set All numbers under the control are intelligent roadblocks numbered 0; A, B, C, and D keys correspond to forward, backward, left turn, and right turn functions; among them, A, B, and C are multiplexed keys, and correspond to A, B, and E (Five of them) Groups have the function of selecting all groups, the * key is used as a multiplexing signal distinguishing key, when A, B, C, D are used as forward, backward, left turn, right turn functions, you need to press * at the same time word key.

The matrix switch is pressed to provide a low-level signal, and the main control unit sends a signal through Bluetooth to control the intelligent roadblock. When controlling the smart roadblock to move forward, backward, turn left, or turn right, keep pressing the * key and one of the keys A, B, C, and D to realize the continuous response of the smart roadblock, and release the button to stop the response of the smart roadblock. Since the control mode is designed with multiple combinations of single selection and multiple selection, it can work in the most suitable control mode according to needs.

3. Practical and innovative concept of intelligent roadblock system design

The main reasons for the applicability of this barricade are:

(1) Simple mechanical structure. A chassis with universal wheels and driving wheels is fixed at the lower part of the barricade for the control and movement of the barricade. The mechanical structure is simple and stable, and has strong applicability and manufacturability.

(2) Easy-to-operate remote control method, the button design of the remote control terminal of the intelligent roadblock is simple and convenient, which can realize multiple control options in different combinations, easy to adjust the formation, and can be controlled from a long distance, which can be suitable for arriving in different competition vehicles in time during the competition Adjust and transform the formation before to form a freely transformable game level.

(3) Simple intelligent roadblock design, only adding chassis, battery, motor, drive module, central control unit, bluetooth module to the original roadblock design, simple design, controllable cost, can meet the competition requirements, suitable for competitions possible risk of accidental damage.

Summarize

The intelligent roadblock system introduced in this article has a simple mechanical structure, easy-to-learn remote control method, simple design and stable function of the intelligent roadblock, and can realize remote control or on-site remote control of the intelligent roadblock under different road conditions. The simple and practical design of the smart roadblock is suitable for various scenarios such as large parking lots, office buildings, road construction, traffic diversion, etc. It solves the problems of physical labor and personal danger in traditional roadblock deployment, and helps solve urban traffic problems. Its low cost and stable functions can realize commercial production and use.

The above are the details of the intelligent roadblock system based on Bluetooth control technology introduced by Shenzhen Zuchuang Microelectronics Co., Ltd. If you have Bluetooth product design and development needs, you can trust us. We have rich experience in custom development of smart electronic products. We can evaluate the development cycle and IC price as soon as possible, and can also calculate the PCBA quotation. We are a number of chip agents at home and abroad: Songhan, Yingguang, Jieli, Ankai, Quanzhi, realtek, with MCU, voice IC, BLE Bluetooth IC, dual-mode Bluetooth module, wifi module. We have hardware design and software development capabilities. Covering circuit design, PCB design, single-chip microcomputer development, software custom development, APP custom development, WeChat official account development, voice recognition technology, Bluetooth development, wifi technology, etc. It can also undertake the research and development of smart electronic products, the design of household appliances, the development of beauty equipment, the development of Internet of Things applications, the design of smart home solutions, the development of TWS earphones, the development of Bluetooth earphone speakers, the development of children's toys, and the research and development of electronic education products.