51 single-chip LCD1602 program detailed
LCD1602
Industrial characteristic LCD. 1602 means that the contents of the LCD are 16x2, which can be displayed two rows, 16 characters per line.
Be
Special interface description
RS: Register Select the input
RS = 1: Point to the data register
RS = 0: Pointing the command register
RW: Read and write control input
RW = 0: Write operation RW = 1: read operation
E: Enable signal input
High power is effective when reading operation;
When writing, the falling edge is effective;
Programming:
#Include "reg51.h"
#Include "intrins.h" // there is a definition of NOP functions
/ * For the delay is short, require the "_nop_" function in US-Level, this function is quite assembled, delayed several microseconds. The NOP instruction is a single cycle instruction, and the delay time can be calculated from the crystal frequency rate, for 12m crystal, delay 1us. * /
#Define uchar unsigned char
#Define uint unsigned int
SBIT RS = P2 ^ 6; / / Define Data Command Select
SBIT RW = P2 ^ 5; // Defines the read and write selection
SBIT E = P2 ^ 7; // Defining Enable
// Note: Which Io port is specifically fixed by your own wiring, not necessarily writing this!
Uchar text1 [] = "welcome to"; // The character to be displayed in the first line
Uchar text2 [] = "limited"; // The character of the second line to display
Void delay_ms (uint z) // millisecond delay function
{
UINT I, J;
For (i = z; i "0; i -) for (j = 110;
J "0; J -);
}
/ / Why is you going to judge?
/ * Because the LCD1602 control chip is also a CPU, it takes longer when handling some of the instructions sent by the host computer. Such as reset commands, full screen clearance commands, etc. In addition, the CPU speed of the LCD1602 is slower. When the upper machine is faster, the LCD1602CPU is not completed, and the subsequent command will not be ignored, which causes the command sequence to reach the LCD1602CPU correctly, so that it is not normal. * /
_Nop_();
E = 1;
_Nop_();
TEMP = P0; // Read the status word of the LCD1602 at this time
_Nop_();
E = 0;
Return (Temp & 0x80); // If you are busy
/ * Status word is the highest bit of Temp (8-bit 2), the highest bit is 1 indicates that the read and write is prohibited, and 0 means it allows read and write, that is, TEMP & 0x80 has a 1 reputation, get 0 means not busy * /
}
/ * In the information of the LCD1602, the read and write operation has a corresponding timing chart, and it is necessary to understand the specific workflow of the LCD1602 to carefully study the timing chart! * /
Void LCD1602_WriteCom (Uchar COM) // Write command
{
While (LCD1602_Readbusy ()); // Judging
RS = 0; // command
RW = 0; // Write
_Nop_();
P0 = COM; // Preparing to send commands
_Nop_();
E = 1; // By the timing diagram, the data exchange is allowed to allow data to be exchanged.
_Nop_();
_Nop_();
E = 0; // By the timing diagram, the enable end is low after completing the data exchange
_Nop_();
_Nop_();
}
Void LCD1602_WriteData (Uchar DAT) // Write Data
{
While (LCD1602_Readbusy ()); // Judging
RS = 1; // Data
RW = 0; // Write
_Nop_();
P0 = DAT;
_Nop_();
E = 1;
_Nop_();
_Nop_();
E = 0;
_Nop_();
_Nop_();
}
Void LCD1602_init () // Initialization function
{
DELAY_MS (15);
WRITE_COM (0x38); // Display mode settings
DELAY_MS (5);
WRITE_COM (0x38);
DELAY_MS (5);
WRITE_COM (0x38);
Write_com (0x0c); // Show
Write_com (0x01); // Display clear screen
Write_com (0x06); // Show cursor
}
Void main ()
{
Uchar i, j;
LCD1602_INIT ();
LCD1602_WriteCom (0x80); // 0x80 is the address of the first character of the first line
For (i = 0; i "10; i ++)
LCD1602_WRITEDATA (Text1 [i]);
LCD1602_WriteCom (0x80 + 0x40); // 0xc0 is the address of the first character of the second line
/ * There are many ways to represent, you can use 0xc0, 0x80 + 0x40, 0x80 | 0x40, etc. * /
For (j = 0; j "10; j ++)
LCD1602_WriteData (Text2 [J]);
}
In fact, LCD1602 has a lot of fun instructions, such as moving right away, everyone can take a look at the relevant instructions in LCD1602, will have a more profound experience.
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