AT89C51 Microcontroller Analog Clock for Graphic LCD

Analog Clock GLCD We use 128×64 pixel graphical LCD having “HY-12864K” is. This adds the file extension of the LCD connections are provided in PDF. 128 × 64 graphic LCD s have the same general structure. Differences spending power connection types and LED colors. Graphic LCDs are managed as two frames (64 × 64) and consists of three parts. Rows, columns and pages. Page 8 of 128 × 64 graphic display as standard and has 64 columns.

Analog Clock Circuit

1. First of all, operations were carried out to make the clock work and make it applicable.

The necessary combinations for the clock were determined. accordingly, we would agree on the necessary designs for the hour and minute hands and the watch by discussing among ourselves.

2. The necessary elements for the clock were determined and the elements were supplied.

We have determined the elements that we will use in the circuit. These elements were first tested in the computer environment. Then, according to the operating state of the circuit, the application area was passed.

Extraction of source codes for graphic LCD

Since we do not have much information about graphic LCD on this subject, general information about graphic LCD was collected over the internet and similar applications made with graphic LCD were examined. The pdf file showing the graphic lcd leg connection to be used later was found on the internet and examined in general.

The graphic LCD we will use is “HY-12864K” with a width of 128×64 pixels. The links of this LCD are given in the attachments in the PDF file. 128×64 graphic LCDs generally have the same structure. The differences are power consumption, connection types and led colors. Graphic LCDs are managed as two frames (64×64) and consist of 3 parts. Row, Column and pages. The 128×64 graphic display has 8 pages and 64 columns as standard.

Each page has 8 rows in one column. And for the management of these 8 lines, it is necessary to send the necessary binary codes to the DB0-DB7 data line. For example, if we want to send 1111 1111 information to the graphic LCD. Its equivalent is FF (0xFF) in hexadecimal. When the figure below is examined, the code sequence required to display the number “1” on the graphic LCD is as follows.

{0x00.0x00.0x00.0x03.0x03.0xFF,0xFF,0xFF}

Pages are created with this type of coding, and the pages are created according to this coding type and sent to the graphic LCD. In our circuit, a code sequence is sent to the circuit for every second, thus creating seconds with minutes and minutes with hours.

Graphic LCD commands

Some functions need to be added in order to be able to perform operations on the graphic LCD. In the G_LCD.h library, terminal definitions, delay function, int value printing function to graphic LCD, int value reading function from graphic LCD, integer printing function to the point whose coordinates are given on graphic LCD, filling and cleaning process of graphic LCD screen, It has the function of initializing the graphic LCD and printing letters on the graphic LCD. This library must be added to the program.

Programming with Keil

After these preliminary applications, we compiled the source codes that we will send to our 8051 microcontroller by writing them into the keil program. Later, these codes were compiled and errors were found. The errors found were corrected, albeit partially, and compiled. Then, this stage was completed by creating the hex file required to send our codes to 8051.

Simulating the prepared program in the proteus

At this stage, first of all, our staff members were called from the library and the circuit was created. By establishing connections, source codes were uploaded to our graphic LCD and circuit work was examined.

Analog Clock circuit keil source code proteus isis simulation schematic files authors: Adem Demir, Sezgin Gültekin, Cem Şahan