Intelligent dot matrix electronic display control system design
The intelligent dot matrix electronic display is based on serial-to-parallel dynamic scanning technology, with a microcontroller as the core and a necessary peripheral circuit design. The system is mainly composed of single-chip microcomputer control, electronic screen drive display, brightness adjustment, clock timing, voice prompt and key control LCD output update. The character code generated by the font software is stored in the single-chip microcomputer system, and the data is sent to the display screen by the serial output mode through the corresponding program control. After the display circuit performs serial-to-parallel conversion, the data is sent to each column, and the decoding circuit performs line scan driving, so that the progressive display loop realizes character display. By controlling the LED lighting time, the brightness is continuously adjustable, real-time temperature time display is realized by the clock and temperature module. It realizes multi-machine communication, and the master and slave work at the same time, realizing the dot matrix display of the main station to control multiple places.
1 Introduction
The LED electronic display screen is an ideal public information display medium for displaying video signals such as texts and images. It has played a good role in improving the image and service level of the government administrative departments, enterprises and institutions serving the public. In addition to the conventional functions of the electronic screen, the LED electronic display designed in this paper is also designed to remotely and intelligently control the electronic display through the Internet.
2, hardware circuit design
The hardware design uses the controller AT89S52 as the control core. Based on the RTX51 real-time multitasking operating system, combined with the clock design and the peripheral circuits required to complete the LED driver , control and display. The entire hardware design block diagram is shown in Figure 1.
Figure 1 dot matrix electronic screen design hardware block diagram
2. 1 single chip system design
The single-chip microcomputer selects the AT89S52 single-chip microcomputer type produced by ATMEL. The AT89S52 is a low-power, high-performance 8-bit microcontroller with on-chip 8 KB flash programmable/erased read-only memory, allowing online programming or adopting general non- The lost memory programmer repeatedly programs the program memory. Users can use the keyboard to control the system to pre-store different performance styles using FlashROM (AT29C040A). The MCU can also communicate with the computer using the R232 port. The computer implements the control system functions and further remotely operates via the Internet, allowing the system to display different LED styles in real time.
2. 2 LED display driver module design
In this system, the LED display adopts double tubes, and the double primary color display 8×8 dot matrix constitutes a 32 line×64 column display. The large display interface not only increases the display amount of information at the same time, but also increases the observability of the screen. The three colors (red, yellow, green) display makes the display interface color no longer monotonous. The displayed information is no longer limited to text, and can display a simpler picture with more powerful functions. The large display requires more drive and data transfer. In order to improve the utilization efficiency of the device, the system divides the display surface into two zones, A and B. Each zone has 16 74 HC595s, 8 of which drive the red tube of 8 × 8 dot matrix in each zone, and the other 8 drives Yellow light.
WARNING!
Do not plug two or more meters together!
IMPORTANT
Don't plug in an appliance where the load exceeds 16 Amp. Always ensure the plug of any appliance is fully inserted into the meter outlet. If cleaning of the meter is required, remove from mains power and wipe meter with a dry cloth.
KEYBOARD DEFINITION
1). SET: Set price with button UP.
2). MODE: Exchange display state.
3). UP: Set price combined with button SET.
GENERAL FEATURES
1).Display line power.
2).Display and memory accumulative total power quantity.
3).Display and memory total power charge of price.
THE DATA DISPLAY
Press MODE button the data displays as follows:
W →KWh →PRICE →COST/KWH
↑_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _↓
1). Plug in socket and power on, the meter will display real power.
2). Press MODE button once again and release, the meter will display accumulative KWh.
3). Press MODE button once again and release, the meter will display total power charge.
4). Press MODE button once again and release, the meter will display COST/KWH.
SETTING PRICE OF COST/KWH
1). Press SET button during display COST/KWH,the first digital COST/KWH flash, press UP button to set it.
2). Press SET button once again and release, the second digital COST/KWH flash, press UP button to set it.
3). Press SET button once again and release, the third COST/KWH flash, press UP button to set it.
4). Press SET button once again and release, the fourth COST/KWH flash, press UP button to set it.
5). Press SET button once again and release, the radix point COST/KWH flash, press UP button to set it.
DATA CLEAR
Press and hold MODE button for 5 seconds will clear KWH,PRICE and COST/KWH data.
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