Target-driven human-machine interface design - Database & Sql Blog Articles

Single chip microcomputer STM32L151CCU6

Mobile phone crystal 3.2*2.5mm 3225 26M (26.000MHZ) 7.5PF 10PPM 20PPM 30PPM

SMD aluminum electrolytic capacitor

1206RGB (single)

Human-computer interface (human-computer interface), also known as user interface, human-computer interaction, human-machine interface, etc., is the medium for transferring and exchanging information between people and machines. It is a comprehensive operating environment in which users use computer systems. In the competition of commodities, the success of an application system depends to some extent on the user's experience of using the interface. Therefore, the design of the human-machine interface plays an important role in the design of the application system. Embedded systems emphasize the real-time, simplification of human-machine interface operations, emphasizing the time-space efficiency of specific applications on a particular platform. In the traditional small system design. Program design generally uses front and back working methods. The application is an infinite loop. The corresponding function is called in the loop to complete the corresponding operation. The critical time operation (crlticaloperation) is guaranteed by the interrupt service. Because the information provided by the interrupt service has to wait until the background program goes to the step of processing this information. This kind of system is worse than the actual can be done in dealing with the timeliness of information. The worst-case task-level response time depends on the execution time of the entire loop. Because the execution time of a loop is not constant, the exact time that a program passes through a particular part is undetermined. If the program is modified, the timing of the loop will also be affected.

The real-time operating system breaks down applications into multitasking, simplifying the design of application software. Good multi-tasking design helps to improve the stability and reliability of the system and guarantee the real-time performance of the system. Many real-time operating systems provide specialized functions that simplify the testing of programs.

1, system design

As shown in FIG. 1, the human-machine interface system adopts a text menu mode operated by a keypad, and is used in an embedded digital video recording DVR (Digital Video Recording) system. The μC/OS-II is transplanted on the MSP430F149 to independently realize the function of the human-machine interface. The user inputs the command through the keyboard, sends it to the main system after processing by the single-chip microcomputer, and displays the corresponding information on the monitor through the OSD (0nScreenDisplay) function of the dedicated chip. On; the user performs menu operations based on the information on the monitor to form a human-machine interaction.

The debugging tool EmbeddedWorkbench corresponding to the MSP430 microcontroller system can track the running of the program. By running EmbeddedPC on the PC, you can track changes in various parameters in the program and check the memory usage of the microcontroller.

Conclusion

After the system uses μC/OS-II, the overall performance of the system has been greatly improved. Before using the real-time operating system. Use the front and back of the program design. When it is necessary to display more data on the screen and need to receive data at the same time, the single chip processing is not timely, and the working tool ReceivebenCh can see that the data frame received by the receiving buffer is incomplete, and the data cannot be correctly displayed on the screen. After the operation of the operating system, the work is reliable, and the response speed of the system, that is, the real-time performance has been greatly improved. The human-machine interface and the embedded main system introduced in the paper are independent modules, which can flexibly load the control module on the single-chip microcomputer, and are suitable for application in various embedded systems.