51单片机计算器lcd1602代码

以下是一个简单的基于51单片机和LCD1602的计算器代码：

#include <reg52.h>
#include <stdio.h>
#include <string.h>

#define LCD_DATA P0
sbit RS = P2^0;
sbit RW = P2^1;
sbit E = P2^2;

char buffer[17]; // 用于存储LCD上显示的字符串
char keypad_map[4][4] = {{'1', '2', '3', '+'},
                       {'4', '5', '6', '-'},
                       {'7', '8', '9', '*'},
                       {'C', '0', '=', '/'}};
char stack[17]; // 用于存储用户输入的数字
int stack_top = 0; // 栈顶指针

void delay(int i)
{
    while(i--);
}

void lcd_write_cmd(unsigned char cmd)
{
    LCD_DATA = cmd;
    RS = 0;
    RW = 0;
    E = 1;
    delay(50);
    E = 0;
}

void lcd_write_data(unsigned char dat)
{
    LCD_DATA = dat;
    RS = 1;
    RW = 0;
    E = 1;
    delay(50);
    E = 0;
}

void lcd_init()
{
    lcd_write_cmd(0x38); // function set
    delay(500);
    lcd_write_cmd(0x06); // entry mode set
    delay(500);
    lcd_write_cmd(0x0c); // display on/off control
    delay(500);
    lcd_write_cmd(0x01); // clear display
    delay(500);
}

void lcd_display(char* str)
{
    int len = strlen(str);
    if (len <= 16) {
        lcd_write_cmd(0x80); // set DDRAM address to 0x00
        for (int i = 0; i < len; i++) {
            lcd_write_data(str[i]);
        }
        for (int i = len; i < 16; i++) {
            lcd_write_data(' ');
        }
    } else {
        for (int i = 0; i < 16; i++) {
            lcd_write_data(str[i]);
        }
        lcd_write_cmd(0xc0); // set DDRAM address to 0x40
        for (int i = 16; i < len; i++) {
            lcd_write_data(str[i]);
        }
    }
}

void push(char ch)
{
    if (stack_top < 16) {
        stack[stack_top++] = ch;
    }
}

int pop()
{
    if (stack_top > 0) {
        return stack[--stack_top] - '0';
    } else {
        return 0;
    }
}

void clear_stack()
{
    stack_top = 0;
}

int calculate(char op)
{
    int num2 = pop();
    int num1 = pop();
    switch(op) {
        case '+':
            return num1 + num2;
        case '-':
            return num1 - num2;
        case '*':
            return num1 * num2;
        case '/':
            return num1 / num2;
        default:
            return 0;
    }
}

void main()
{
    lcd_init();
    lcd_display("    Calculator");
    delay(500);
    lcd_write_cmd(0x01); // clear display
    while(1) {
        for (int i = 0; i < 4; i++) {
            P1 = ~(1 << i);
            for (int j = 0; j < 4; j++) {
                if ((P1 & (1 << (j + 4))) == 0) { // 判断按键是否按下
                    if (keypad_map[i][j] == '=') {
                        int result = 0;
                        char str_result[17];
                        while (stack_top > 0) { // 计算栈内表达式
                            result = calculate(stack[--stack_top]);
                        }
                        sprintf(str_result, "Result: %d", result);
                        lcd_display(str_result);
                        clear_stack();
                    } else if (keypad_map[i][j] == 'C') {
                        clear_stack();
                        lcd_write_cmd(0x01); // clear display
                    } else if (keypad_map[i][j] == '+' ||
                               keypad_map[i][j] == '-' ||
                               keypad_map[i][j] == '*' ||
                               keypad_map[i][j] == '/') {
                        push(keypad_map[i][j]);
                        buffer[strlen(buffer)] = keypad_map[i][j];
                        lcd_display(buffer);
                    } else {
                        push(keypad_map[i][j]);
                        buffer[strlen(buffer)] = keypad_map[i][j];
                        lcd_display(buffer);
                    }
                    while ((P1 & (1 << (j + 4))) == 0); // 等待按键松开
                }
            }
        }
    }
}

该代码使用了一个简单的栈来实现计算器的功能，可以通过按下不同的键盘按钮输入数字和运算符，并在LCD上显示结果。