Question

我们目前正在使用Arduino和LCD制作一个4x3计算器。我们缺少按钮，因此每次操作不是一个按钮，所有操作只有一个按钮。到目前为止，它只是添加。你怎么做的事情，如果我按下OPERATION按钮一次，它会增加，如果两次，减法等。

#include <Keypad.h>
#include <LiquidCrystal.h> //import lcd library


LiquidCrystal lcd(12, 11, 5, 4, 3, 2); //lcd pins

//LiquidCrystal lcd(5,4,3,2,1,0); 
const byte ROWS = 4; // four rows
const byte COLS = 3; 

//define the keymap
char keys [ROWS] [COLS] = {
  {'1', '2', '3'},
  {'4', '5', '6'},
  {'7', '8', '9'},
  {'+', '0', '='}
};

byte rowPins[ROWS] = {
  9 ,8 ,7 ,6}; //connect keypad ROW1, ROW2, ROW3, ROW4 to these arduino pins
byte colPins[COLS] = {
  13, 10, 1}; 
//create the keypad
Keypad myKeypad = Keypad( makeKeymap(keys), rowPins, colPins, ROWS, COLS );

//variables declaration
boolean valOnePresent = false;
boolean next = false;
boolean final = false;
String num1, num2;
int ans;
char op;

void setup(){
  lcd.begin(16,2);
  lcd.setCursor(2,0);
  lcd.print("Calculator");
  delay(2500);
  lcd.clear(); //clears the LCD screen and positions the cursor in the upper-left corner. 
}

void loop(){
  char key = myKeypad.getKey();

  if (key != NO_KEY && (key=='1'||key=='2'||key=='3'||key=='4'||key=='5'||key=='6'||key=='7'||key=='8'||key=='9'||key=='0')){
    if (valOnePresent != true){
      num1 = num1 + key;
      int numLength = num1.length();
      lcd.setCursor(15 - numLength, 0); //to adjust one whitespace for operator
      lcd.print(num1);
    }
    else {
      num2 = num2 + key;
      int numLength = num2.length();
      lcd.setCursor(15 - numLength, 1);
      lcd.print(num2);
      final = true;
    }
  }

    else if (valOnePresent == false && key != NO_KEY && (key == '/' || key == '*' || key == '-' || key == '+')){
    if (valOnePresent == false){
      valOnePresent = true;
      op = key;
      lcd.setCursor(15,0); 
      lcd.print(op);
    }
  }

  else if (final == true && key != NO_KEY && key == '='){
    if (op == '+')
    {
      ans = num1.toInt() + num2.toInt();
    }
    else if (op == '='){
      ans = num1.toInt() + num2.toInt();
    }
   /* else if (op == '+')
    {
      answ = num1.toInt() - num2.toInt();
    }
   */ 



      lcd.clear();
      lcd.setCursor(15,0);
      lcd.autoscroll();
      lcd.print(ans);
      lcd.noAutoscroll();
  }

}

Answer 1

您可以使用数组来完成此操作。通过实现具有小延迟的while循环，您可以在每次按下按钮时继续遍历数组中的位置，直到数组超时。以下是一些可以用来实现它的例子。

char ops [4] = {'+','-','/','*'};
int del = 2500;
int strt = millis();
int  location = 0;
while (millis() - strt < del) {
  key = myKeypad.getkey();
  if (key == '+') {
     if (loc == 3) {
      location = 0;
     }
     else {
      location += 1;
     }
     strt = millis();
  }
}
op = ops(location);

Arduino计算器（按下多个按钮）

1 个答案: