subject: The figure shows the LCD module ACM19264ASB [print this page] The figure shows the LCD module ACM19264ASB
Introduction, in the last PIC microcontroller-based intelligent system, the Chinese character display module is a very important component element, which is extensive, convenient operation, easy adjustment, to facilitate its employment. However, single-chip computer revealed several problems with Chinese characters. First, single-chip computer resources
Introduction, in the last microcontroller-based intelligent system, the Chinese character display module is a very important component element, which is extensive, convenient operation, easy adjustment, to facilitate its employment. However, single-chip computer revealed several problems with Chinese characters. First, single-chip computer resources are limited, we can not take up too much to reveal the character of resources; second, store and read the more complicated character, difficult to use; Third, Chinese characters are used by dot matrix display, often writing mode with the LCD, which changes and adjustments, are different. It is noteworthy, Chinese display on a chip can not be achieved based on the computer LCD characters. Using the LCD has many advantages, not only can display Chinese characters, Chinese characters can also dynamically moving and rolling, from the refusal to toe the first to realize the mixed character and graphics displays, low power consumption figures at the same time. 2 single-chip computer based on the Chinese display and cross the intersection point of the principles and 2.1 dot matrix Chinese font and characters such as the junction with the general store 16 * 16,, 24 * 24Dot matrix (ie character dot matrix), each from 32 16 bytes character dot matrix), or 72 bytes (24 dots) is described. According to the different scripts of Chinese characters can also be divided into the song mentioned matrix, block matrix of the letter, the black ghost and so on. Character design, character matrix is actually a graphic. As for the intersection of 16 dot matrix and matrix, written in a 16 * 16 mesh Chinese characters, Chinese character may correspond to a stroke, head over there some of the network, or network corresponds to 0, corresponding to a grid for each 1 or 0, the link to see to the corresponding grid is 1, it is such a character. Chinese characters that point of bytes stored in such a character matrix. To find the characters easy to point the matrix, each character corresponds to a byte within a one yard. Lattice with an initial byte code, can be calculated character inside it. To 16 lattice, for example, is now proved. The first calculation, until it's area code characters in the library, the formula is: = a yard inside the area code of the first byte - 160 yards = two bytes of internal code - 160 intersection matrix can be obtained, and the next byte Chinese character library's area code, and then position: (94-bit code + area code *) * 32 can then be read out continuously 32 byteses points behind formed the word matrix data. 2.2 to display Chinese characters take up too much resourceses (such as 16 dots, each character requires 32 byteses), it is usually in the EEPROM Store, without having to reveal a character, figure out its area code first, then find the back lattice location of the house, bring up this point in the sequence from EEPROM word stored in the buffer matrix data, sending liquid crystal revealed last word copies of this order. Chinese characters to those that need storage and LCD display modes were different. The text uses a different display method, that is, characters, symbols and numbers (To save space, show the program, using ahead of time, you can press the number to 8 * 16 dot matrix), compiled into a text file, make the appropriate and small with segment of small programs Store, this little character dot-matrix font matrix data from the General to take Chinese character library. This process is a change and adjust to get the new Store, a new word in the EEPROM in the stock finally solidified. The single-chip computer to read out only under the code-byte matrix, which is the Chinese character display request sent to the LCD. Reduce the burden of single-chip computer, remove the yard, and asked the status of work at home, change, adjust the red tape to find out, etc., have increased the reliability of the system.
Table 116 dot matrix character font storage
A typical use of the three small Chinese custom word library can choose ucdos stock shares, such as 16 characters, dot matrix character stock hzk16. Requires 256K of space, using a larger EEPROM, it is inconvenient to read, there are very few practical applications require the characters, so we can, through their own little Store, only the systems in these small characters required character library. On the one hand to save reading time, saving resources on the other hand, Digupi great. Due to space limitations, only flow diagram (assuming that the demand for an early Chinese text has been written to the file) Here, as shown. 1.
Figure 4 The structure and principle of dot matrix LCD display module acm19264asb 4.1 Specifications and Features 1) Power: +5 2) revealed the contents: 192 (list) * 64 (walk) lattice, the number can be displayed, to display 12 * 4 (16 dots) character too 3) of the entire screen matrix; and the CPU 5) interface, using 8 parallel input and output data bus and 8 control lines; 4) 7 orders. Main external interface 1) 4.2 module Vss: Ground 2) D / I: GAO's show db7 - db0 display instruction data as that data is low as the view; 3) R / W: read, write, control; 4 ) E: Enable signal; 5) db7 - db0: data link; 6) CS3, the in CS1: 3 list of groups and drive selector, 7) Reset: Reset Control; 8) V-shaped: Negative voltage drive. 4.3 command interpreter, code-line is 1) [001 / W, for the D / I, db7, db6, db5, db4, db3 time, DB2, DB1's, db0] reveal the switch control [0,0,0,0,1 , 1,1,1, a, d], d = 1 is displayed, and is open to reveal, you can perform various operations and displays 2) to establish and reveal the starting line [0,0,1,1,5 Article A4 paper, A3 in, A2, A1 and A0], the initial line address can be any line of 0 - 63; 3) Set the P address, that is, X address) [0,0,1,0,1,1, 1 , A2, A1 and A0], the one on page 8 of the act, the module up to 64 lines, that is, page 8, 0 - 7 is available; 4) a Y address [0,0,0,1, apolipoprotein A5, A4 paper, a3's, A2, A1 and A0 of the], y can choose from 0 - 63, equivalent to CS3, in CS1, each containing 64 lines, y can choose one of them as a function of the initial line read / write operations, each operation auto increment; 5) Read the state of [1,0, blast furnace, 0, on / off time, RST, 0,0,0,0], where BF is the busy flag, BF = 1 indicates that the internal is operating, do not accept outside orders, on / off, to reveal the flip-flop state, on / off = 1 shows that an open, data showed on the screen, RST = 1 indicates that the internal is initialized to carry not accept any command and data; 6) view data written [0,1, D7 of deuterium, D5 in, D4 class, vitamin D3, D2 and D1, in, D0], load the view displays the data storage unit, Y address pointer automatically increments; 7) to read the data point [1,1, D7 of deuterium, D5 in, D4 class, vitamin D3, D2 and D1, in, D0], read data, auto-increment. It proved that graphics LCD module acm19264asb internal structure, as shown. Second, the 4.4 module in the form of major hardware. IC4 is a line driver, IC3's, IC1, in order to list the driver, each driver device includes the following features: instruction register (IR), the data register (DR), busy flag (BF), revealed control flip-flop (DFF), XY address counter, view the data RAM (DDRAM in), Z address counter (ie, line scan counter to complete sweeping delegation of the automatic increment to 0 in circulation - 63, so the screen can be achieved scroll).
Table 4.5 shows the address the data storage unit 2 to display and reveal the address of the data storage unit.
DDRAM address in the list of graphic LCM acm19264asb Table 2
5 Chinese characters library can be found, from Table I and Table II restructuring and conversion of liquid crystal displays, dot matrix Chinese character library need to adjust and change the process to reveal the LCD monitor.
Specifically, the need to walk the first dot matrix, dot matrix and list into, and then open more than 180 degrees. Appropriate procedures are as follows: # include the header file to add, and then set the array: unsignedintfarhzlib [16 * 1000]; Chinese character library point, and then change the matrix array, byte [8 * 2000] the load unsignedintfarhzxlib; Chinese character library points change, and single-byte load, characters, and then change the library array matrix array, according to the changed matrix by 16 points each byte of data loading, fast and convenient, single-byte Chinese character library array load. Behind the main program with the conversion routine finally function. Conversion routines are as follows: voidhz_tzh () {INTI, J type, K getbit; as (k = 0, K in (I = 0 {; I = 0 for J - -) {getbit = (hzlib [16 * K ]>> (15 - )) - (hzlib [16 * K ]>> (16 - I)) * Second, it gets listed in the conversion hzxlib behavior to achieve the same position, take each and bytes + = getbit = 8; the J - -)?? {getbit = (hzlib [16 * K ]>> (31 - )) - (hzlib [16 * K ]>> (32 - )) * 2hzxlib [I + 32 * k] of the + = getbit
