电子存包柜- 英文

1、Design of electronic storage cabinet based on RTOS SmallDepartment of electronics and communication engineering, PSG college, Coimbatore IndiaAbstract：This paper introduces the design principle of the electronic storage control system based on RTOS Small, and introduces the system used in this syste

2、m to make the controller, which can manage the N storage cabinet at the same time. The door lock is controlled by the electromagnetic valve, when customers need to save the package, can go to the lockers before press the open button, the microcontroller receives a pulse signal, and the system I/O po

3、rt to send corresponding signals to control the electromagnetic valve lock door will be an empty box is opened, the customer can save the package and the door shut. When the customer needs to take the package, will as long as the bar code placed in front of the bar code reader, barcode reader bar co

4、de information collected by the output voltage signal corresponding to the microcontroller, the password system is relatively consistent, send out signals to the solenoid valve is open, the customer can remove the package.Key words：Small RTOS；electronic storage cabinet; save package1、IntroductionRTO

5、S RAM Small demand for small, very suitable for such a relatively small resources of the system. RTOS has a multi tasking, strong real-time, and can be reduced to the kernel, making the design of real-time applications, expansion and maintenance easier. The introduction of the idea of RTOS, instead

6、of the traditional software design method, so that it is no longer a single thread structure, through the application is divided into several independent tasks, RTOS makes the design process of application system is simplified. In this paper, the software design of electronic storage cabinet based o

7、n single chip microcomputer is combined, the design idea of RTOS Small and the application of message queue communication mechanism are briefly analyzed.1.1 basic principles of RTOS51 SmallRTOS51 Small is a very small kernel, fully integrated in the C51 KEIL compiler, only take less memory space, yo

8、u can run in the 51 single chip microcomputer system without external data memory. The kernel is responsible for initializing and open, other tasks scheduling system, according to the priority of tasks, a reasonable distribution of CPU in different time between tasks, the kernel can generally provid

9、e task scheduling and interrupt service function. A program and a task, the task of each separate, independent implementation of the part called thread. All event driven and time driven are reflected in the settings of the corresponding task identification and thread identification. When the hardwar

10、e environment, on the basis of the identification, by arranging the system interrupt and task scheduling algorithm adjust the response, by using the method of setting up environmental variables, which can interrupt exit after return to any more than one set of entrance in one to perform, and effecti

11、vely solves the key problem of flexible switching of foreground and background tasks thread. RTOS Small 51 user tasks with a running state, ready state, wait and suspend, interrupt service program. At any moment, the state of the task is one of these four states. In order to save memory, create and

12、delete mission OS dynamic, with the function OSSTART () to start a multi tasking environment, OS took all the tasks set up, and set them as the ready state, the highest priority task to run. Only when all the priority is higher than its task to wait. Ready to enter a state of operation. The schedule

13、r will be the top priority of the task ready list as the next task to be performed.Task call os_wait function, pending the current task, waiting for one or several intervals (K_IVL), time out (K_TMO), signal (K_SIG) events. If waiting for event has occurred, continue to implement the current task; i

14、f waiting for events did not occur, the corresponding waiting sign, suspend the task to task switching program segment switch to the next task.Small RTOS51 (init) by performing a function to register initialization, call the function OSSTart () to initialize each task stack and perform the first tas

15、k, and the choice of the first task for the reason that the task priority level. In the selection process to complete the task of scheduling.1.2 communication between tasksCommunication between tasks using the message queue, after 3 steps: to create a message queue OSQCreate (), to the message queue

16、 message OSQPost (), take message OSQPend (). Call the OSQPost () function to send the message, if you already have a task waiting for the message, immediately turn to wait for the news task, if the message queue is full, is unable to deliver the message, return an error. If the message queue is not

17、 full, but there is no other task waiting for the message, then. It is worth noting that, when the queue is full, the function does not suspend the current task, so call the function of the task should be judged to return the condition, if the message is full, it should be hung from the current task

18、. When receiving a message, if the message queue is empty, the task of taking the message will be suspended until a message is received in the message queue.2. Application examples2.1Hardware platform For example, the system block diagram is as follows.The electronic storage cabinet can control the

19、maximum number of goods storage box is 32, divided into about 16 boxes, the picture only draw 16 road control. Control chip using AT89C55 microcontroller, with real-time clock module, bar code reader, liquid crystal display module, thermal printer composition, designed to three PCB board.1 master co

20、ntrol board, the users storage and access to the user interface, save the package password, display the user access to the password in the process of the password input and the state of all 32.The 2 door control panel is composed of three parts, the first part of the box is detected, including 16 in

21、frared detection input, 16 way infrared emission control drive. The second part of the 16 road relay control box is controlled by 16 small DC motor constitute open 16 box control. In the third part, the status of the box door is detected, and the opening / closing of the 16 boxes is detected.3 acces

22、s package barcode printing, voice prompt, the whole system is composed of 4 single chip with the MCU control work, operation management package users and record the history parameters, then sends commands to the microcontroller the distribution of empty container and print out the package, to the us

23、er.2.2 software designThe electronic storage cabinet mainly comprises a key processing module, a display processing module and a communication processing module. Therefore, the task can be divided into key display, receive data, command processing, sending data and other 4 tasks.The microcontroller

24、receives the user according to the package to enter a password, password and key processing, display box display, send out commands for example, illustrate the main design idea.After the system initialization, the article uses function OSSTart () to set up a multi task environment, set up the task s

25、tack for each task, and successfully set up 4 tasks, waiting for the wake of the corresponding task. Users only need to define functions they want to achieve for the mission, declared in the Config.h task function name and its priority, and the number of their code can be, no traditional programming

26、 under the kind of general relations, the system will automatically run the code. RTOS51 Smal transplantation is mainly configured OS-CPU.H, OS_CFG.H and CONFIG.H three files, where the OS_CFG.H file is mainly used for the operating system and the reduction of the clock and other related configurati

27、on.Define 4 tasks in the CONFIG.h file.#ifnedf. .#endifLimited to the length of the single chip microcomputer to send and receive data procedures.3. SummaryThe real-time multi task operating system makes programming more efficient, maintenance and modification more convenient, so it is widely used a

28、t present, especially in the embedded system. At the low end of the 51 single chip application, the use of real-time multi tasking operating system, using RTOS Small multi tasking platform for system application design and improvement, also has practical significance.In this paper, the innovation points: the idea of RTOS Small multi task application in a specific single chip microcomputer control electronic storage cabinet system software design, the message queue based on the task of communication programming me