subject: DSP-based digital oscilloscope graphical user development - embedded, Oscilloscope - Electronics Industry [print this page] DSP-based digital oscilloscope graphical user development - embedded, Oscilloscope - Electronics Industry
Introduced a number of applications in RIGOLDS1000 Series Oscilloscopes On the implementation of graphical user interface, focusing on analysis of the graphical user interface (GUI) design ideas, and briefly introduces the software design structure and processes.
Application areas as embedded systems continue to expand, the system complexity is ever increasing. So in Embedded System graphical user (GUI), has become a trend. In the measuring instruments, the graphical interface is also widely used, one is embedded in the operating system, most of the graphical user interface (GUI) is the operating system (such as OS, WinCE, Linix) with the support of the call system kind of API function implementation. These operating systems provide for the realization of a large number of libraries GUI functions for programmers to provide a good platform for interface design. But this embedded technology, the high hardware requirements, equivalent to embedding a computer, such as the use WinCE can be very convenient to design a Windows-style graphical interface. The other is a direct use of DSP technology, development of small systems. This system streamlined, low hardware requirements, but the function of the relative one. This figure
article Oscilloscopes Is a common source Varitronix (RIGOL) has introduced the DS1000 series, complete autonomy to complete its design, close to the Chinese habits. The graphical user interface (GUI) is in the VisualDSP + +4.0 Kernel based on the development of the interface style closely associated with the instrument function. Upon completion of the instruments such as waveform and the menu displayed on the basis of, RIGOL team also made some generic graphical user interface, such as File Manager. Of course, the design of graphical user interface, a powerful aspect in the far compare with WinCE, etc., but for the user of the apparatus, the already convenient enough?? Because, after all, the instrument graphical user interface, and is not a Pocket PC PDA's graphical user interface.
User interface principles Implementation graphic user interface, requires hardware, software support. Shown in Figure 1, by operating the platform (operationplatform) deployment, call display program, display program refresh the display buffer, and then by the display driver, the display shows the contents of the cache to LCD screen On.
Figure 1 RIGOLDS1000 digital oscilloscope graphical user interface implementation schematic
Following is a summary description of Figure 1, several major components.
GUI graphical standard library Graphic user interface to display a variety of graphics, design, in addition to hardware support, but also need strong software support. Which (GUI) graphics standard library for the most basic, but essential. Graphical user interface (GUI) graphics standard library, including basic drawing points, draw lines, draw rectangle, filled rectangle, draw circle, place bmp format images, display, English and other functions, the more powerful the graphics library functions, can support more sophisticated graphical user interface (GUI).
GUI operating platform support Only draw graphics with standard graphics library, to achieve the graphical user interface, or not enough. Graphics library is an indispensable single screen, but to the formation of organic, operable graphical user interface, but also the background of a stable and powerful operating system platform.
Platform outside the user's input (usually keyboard), and the current state of the system to determine next system state, which calls the corresponding GUI interface. So, we realized the graphical user interface.
Achieve graphical hardware schematic RIGOLDS1000 series digital oscilloscope using the 320 234 resolution TFT LCD monitor, through the liquid crystal driver circuit, liquid crystal can properly show the frame sync, line sync, data clock signal (clock) synchronization, show Lattice The data will be written from the SDRAM to the LCD monitor in the display buffer, which shows color images.
Can be seen from Figure 1, if you want to update the LCD display, and we only need to update LCDbuffer the display data on it.
Graphical user interface (GUI) software for design ideas
Interface type of division For the graphic user interface (GUI) design can not be a simple, unified completed, taking into account the user interface under various circumstances. Based on these interface with the common ground, we will be divided into the following types of these interfaces, the same type of interface will have the same or similar functional areas. Each interface will have the appropriate procedures, there are specific data structure.
According to different functions implemented interface is divided into the following categories:
A. background grid display interface; B. waveform display interface; C. help document browser interface; D. menu display interface; E. File Manager browser interface; F. file name input interface; J. prospects for content display interface (including the various parameters to display information, measurement information, and prompt information, etc.).
The interface types shown in Figure 2,3.
Figure 2 RIGOLDS1000 graphical interface shows a digital oscilloscope
Figure 3 RIGOLDS1000 digital oscilloscope GUI note 2
Interface between regional and external input with the response
Can see from the above shows that although all kinds of graphics, but they all share common attributes can be abstracted into some data structure. Data structure is a graphical interface is like the soul master data structure, you can make a graphical interface to change accordingly.
Then how to design, control, change the data structure to achieve on a graphic user interface (GUI), crucial. To respond to external user input, we need to develop a mechanism to run the rule, but the mechanism is the state machine run rule (systemstatusmachine), is the user for the operation of devices in the operating platform (operationplatform). The operation according to law, our system changes according to external input to a variety of interface data structures used to achieve the user graphic interface.
Course, in actual design, the operating platform not just to change the GUI data structure, but also consider the task scheduling and other modules in the data structure changes.
Digital oscilloscope graphical user interface (GUI) software design process
Design a good graphical user interface, is a huge and big and small projects. Involved in all aspects of mutual relations, and also involved
