课程中心/51单片机教程/【10】液晶屏LCD1602

【10】液晶屏LCD1602

本课资源下载

共 6 个资源

P10LCD1602

本节课的标准源代码工程/可供参考

V1.0压缩包55 KB

LCD1602A 5V

液晶屏

PDF 文档4.1 MB

LCD1602_c

文档资料8.5 KB

LCD1602_h

文档资料3.8 KB

Delay_c

文档资料516 B

Delay_h

文档资料144 B

课程笔记

本节目标概括

创建工程 > 编写点灯代码 > 编译HEX文件 > 下载到学习板 > LCD显示

用LCD1602.c完成LCD屏的显示

编译并下载程序到学习板，即可看到程序效果：LCD屏显示数据

LCD1602液晶显示屏

LCD （ Liquid Crystal Display 的简称）液晶显示器。能够同时显示16x2，32个字符，是一种专门用来显示字母、数字、符号等的点阵型液晶模块。
LCD1602主要用来显示数字、字母、图形以及少量自定义字符。可以显示2行16个字符，拥有16个引脚，其中8位数据总线D0-D7，和RS、R/W、EN三个控制端口，工作电压为5V，并且带有字符对比度调节V0和背光源AK。

驱动库移植

在本课资源下载处下载LCD1602.c , LCD1602.h和 Delay.c , Delay.h 文件（LCD1602的驱动库需要用到delay函数）
如下图，将这四个文件复制在需要移植的工程的根目录

打开该工程，点击图示的方块图标

点击添加文件，查找范围为工程的路径，按住ctr键选中两个c文件，点击Add，然后关闭即可看到文件已添加完成

5.在文件中#include"LCD1602.h"即可调用LCD驱动库函数

例程讲解

下面介绍了如何自己实现该例程的功能

lcd1602驱动库功能函数代码介绍：

lcd1602.c

C语言

1/**
2 * @brief  LCD1602 初始化
3 * @note   按数据手册推荐的 8 位初始化流程执行，确保上电后进入已知状态
4 */
5void LCD_Init(void)
6{
7    
8    LATCH_HOLD_ALL(); 
9
10    LCD_RS = 0;		/* 先置为命令模式 */
11    LCD_EN = 0;   /* 使能脚拉低 */
12
13    /* Follow the recommended 8-bit initialization flow. */
14    delay(LCD_POWER_ON_WAIT_MS);		
15    LCD_WriteCommand(LCD_CMD_FUNCTION_SET);
16    delay(LCD_INIT_RETRY_WAIT_MS);
17    LCD_WriteCommand(LCD_CMD_FUNCTION_SET);
18    delay_100us(LCD_INIT_RETRY_WAIT_100US);
19    LCD_WriteCommand(LCD_CMD_FUNCTION_SET);
20
21    LCD_WriteCommand(LCD_CMD_FUNCTION_SET);
22    LCD_WriteCommand(LCD_CMD_DISPLAY_OFF);
23    LCD_WriteCommand(LCD_CMD_CLEAR);
24    LCD_WriteCommand(LCD_CMD_ENTRY_MODE);
25    LCD_WriteCommand(LCD_CMD_DISPLAY_CTRL);
26}
27
28/**
29 * @brief  显示一个字符
30 */
31void LCD_ShowChar(unsigned char Line, unsigned char Column, char Char)
32{
33    LCD_SetCursor(Line, Column);
34    LCD_WriteData(Char);
35}
36
37/**
38 * @brief  显示字符串
39 * @note   遇到 '\0' 结束；不处理换行，超出屏宽由 LCD 自身行为决定
40 */
41void LCD_ShowString(unsigned char Line, unsigned char Column, char *String)
42{
43    unsigned char i;
44
45    LCD_SetCursor(Line, Column);
46    for (i = 0; String[i] != '\0'; i++)
47    {
48        LCD_WriteData(String[i]);
49    }
50}
51/**
52 * @brief  显示有符号十进制数
53 * @param  Length 数字部分的显示位数；为 0 时按实际位数显示
54 * @note   符号位固定占 1 个字符，显示在数字前面
55 */
56void LCD_ShowSignedNum(unsigned char Line, unsigned char Column, int Number, unsigned char Length)
57{
58    unsigned char i;
59    unsigned int idata AbsNumber;
60    unsigned char Digit;
61    unsigned char effLen;
62    unsigned char clearCnt;
63
64    effLen = Length;
65    clearCnt = 0;
66
67    LCD_SetCursor(Line, Column);
68
69    if (Number >= 0)
70    {
71        LCD_WriteData(SIGN_PLUS);
72        AbsNumber = Number;
73    }
74    else
75    {
76        LCD_WriteData(SIGN_MINUS);
77        AbsNumber = -Number;
78    }
79
80    if (Length == 0)
81    {
82        effLen = LCD_DecDigits(AbsNumber);
83    }
84
85    for (i = effLen; i > 0; i--)
86    {
87        Digit = AbsNumber / LCD_Power(DECIMAL_BASE, i - 1) % DECIMAL_BASE;
88        LCD_WriteData(Digit + DIGIT_CHAR_OFFSET);
89    }
90
91    if (Length == 0)
92    {
93        clearCnt = (DECIMAL_MAX_DIGITS > effLen) ? (DECIMAL_MAX_DIGITS - effLen) : 0;
94        if (clearCnt)
95        {
96            LCD_ClearChars(Line, Column + 1 + effLen, clearCnt);
97        }
98    }
99}
100/**
101 * @brief  显示 long 型十进制数
102 * @note   先转成字符数组再逆序输出，避免多次调用 LCD_Power
103 */
104void LCD_ShowLongNum(unsigned char Line, unsigned char Column, long Number)
105{
106    unsigned char i;
107    unsigned char TempIndex;
108    unsigned char DisplayLen;
109    unsigned char pdata Temp[10];
110    unsigned long pdata Value;
111
112    TempIndex = 0;
113    DisplayLen = 0;
114
115    LCD_SetCursor(Line, Column);
116
117    if (Number < 0)
118    {
119        LCD_WriteData(SIGN_MINUS);
120        DisplayLen++;
121        Value = 0UL - (unsigned long)Number;
122    }
123    else
124    {
125        Value = (unsigned long)Number;
126    }
127
128    if (Value == 0)
129    {
130        LCD_WriteData(DIGIT_CHAR_OFFSET);
131        DisplayLen++;
132    }
133    else
134    {
135        while (Value > 0)
136        {
137            Temp[TempIndex++] = Value % DECIMAL_BASE + DIGIT_CHAR_OFFSET;
138            Value /= DECIMAL_BASE;
139        }
140
141        for (i = TempIndex; i > 0; i--)
142        {
143            LCD_WriteData(Temp[i - 1]);
144            DisplayLen++;
145        }
146    }
147
148    if (LONG_MAX_CHARS > DisplayLen)
149    {
150        LCD_ClearChars(Line, Column + DisplayLen, LONG_MAX_CHARS - DisplayLen);
151    }
152}
153/**
154 * @brief  显示无符号十六进制数
155 * @param  Length 显示位数；为 0 时按实际位数显示
156 */
157void LCD_ShowHexNum(unsigned char Line, unsigned char Column, unsigned int Number, unsigned char Length)
158{
159    unsigned char i;
160    unsigned char Digit;
161    unsigned char effLen;
162    unsigned char clearCnt;
163
164    effLen = Length;
165    clearCnt = 0;
166
167    LCD_SetCursor(Line, Column);
168
169    if (Length == 0)
170    {
171        effLen = LCD_HexDigits(Number);
172    }
173
174    for (i = effLen; i > 0; i--)
175    {
176        Digit = Number / LCD_Power(HEX_BASE, i - 1) % HEX_BASE;
177
178        if (Digit < HEX_DIGIT_THRESHOLD)
179        {
180            LCD_WriteData(Digit + DIGIT_CHAR_OFFSET);
181        }
182        else
183        {
184            LCD_WriteData(Digit + HEX_LETTER_OFFSET);
185        }
186    }
187
188    if (Length == 0)
189    {
190        clearCnt = (HEX_MAX_DIGITS > effLen) ? (HEX_MAX_DIGITS - effLen) : 0;
191        if (clearCnt)
192        {
193            LCD_ClearChars(Line, Column + effLen, clearCnt);
194        }
195    }
196}
197/**
198 * @brief  显示无符号二进制数
199 * @param  Length 显示位数；为 0 时按实际位数显示
200 */
201void LCD_ShowBinNum(unsigned char Line, unsigned char Column, unsigned int Number, unsigned char Length)
202{
203    unsigned char i;
204    unsigned char Digit;
205    unsigned char effLen;
206    unsigned char clearCnt;
207
208    effLen = Length;
209    clearCnt = 0;
210
211    LCD_SetCursor(Line, Column);
212
213    if (Length == 0)
214    {
215        effLen = LCD_BinDigits(Number);
216    }
217
218    for (i = effLen; i > 0; i--)
219    {
220        Digit = Number / LCD_Power(BINARY_BASE, i - 1) % BINARY_BASE;
221        LCD_WriteData(Digit + DIGIT_CHAR_OFFSET);
222    }
223
224    if (Length == 0)
225    {
226        clearCnt = (BINARY_MAX_DIGITS > effLen) ? (BINARY_MAX_DIGITS - effLen) : 0;
227        if (clearCnt)
228        {
229            LCD_ClearChars(Line, Column + effLen, clearCnt);
230        }
231    }
232}

在主函数main()执行以下代码:

C语言

1#include <stc89c5xrc.h>
2#include "LCD1602.h"
3#include "Delay.h"
4
5// =========== 现象 ===========
6// 注意⚠️ 第一次插上LCD1602时需要拧电位器调下对比度，要不可能完全看不出显示痕迹
7// 现象：LCD1602上循环显示不同内容
8
9void main()
10{
11	unsigned char i = 0;
12	LCD_Init();
13	while (1)
14	{
15		// 显示字符串
16		LCD_ClearLine(1);
17		LCD_ShowString(1, 1, "THIS IS LINE 1");
18		LCD_ClearLine(2);
19		LCD_ShowString(2, 1, "THIS IS LINE 2");
20		delay(2000);
21		
22		// 显示有符号数字
23		LCD_ClearLine(1);
24		LCD_ShowString(1, 1, "Signed Num");
25		LCD_ClearLine(2);
26		LCD_ShowSignedNum(2, 1, -32767, 0);
27		delay(2000);
28
29		// 显示无符号数字
30		LCD_ClearLine(1);
31		LCD_ShowString(1, 1, "Unsigned Num");
32		LCD_ClearLine(2);
33		LCD_ShowNum(2, 1, 233, 0);
34		delay(2000);
35
36		// 显示Hex数字(16进制)
37		LCD_ClearLine(1);
38		LCD_ShowString(1, 1, "Hex Num");
39		LCD_ClearLine(2);
40		LCD_ShowHexNum(2, 1, 0x4CF9, 0);
41		delay(2000);
42
43		// 显示Bin数字(二进制)
44		LCD_ClearLine(1);
45		LCD_ShowString(1, 1, "Bin Num");
46		LCD_ClearLine(2);
47		LCD_ShowBinNum(2, 1, 0x0055, 8);
48		delay(2000);
49
50		// 显示固定长度的变化数字
51		LCD_ClearLine(1);
52		LCD_ShowString(1, 1, "Real Time Num");
53		for (i = 0; i < 25; i++)
54		{
55			LCD_ClearLine(2);
56			LCD_ShowNum(2, 1, i * 25, 4);
57			delay(200);
58		}
59		delay(2000);
60
61		// 演示结束
62		LCD_ClearLine(1);
63		LCD_ShowString(1, 1, "DEMO FINISHED");
64		LCD_ClearLine(2);
65		delay(2000);
66	}
67}

注意一定先移植好头文件，并且使用LCD_Init();初始化函数后才可以编写代码