怎么使用LCD和键盘将十进制数转换为Bınary

键的值是否正确地在第一行上正确地输出？（例如，当按下4时，7行第一行输出：47）？也有可能调试和查看当执行if语句时KPI和KPI1的值是什么？这些可能有助于弄清楚为什么陈述没有评估你所期望的方式。



      以下为原文

    Do the values of the keys pressed output properly on the first row?  (e.g. when you press 4 then 7 does the first row output: 47)?  Also is it possible to debug and see what the values of kpi and kpi1 are when the if statement is executed?  These may help figure out why the statement is not evaluating the way you expect.  

重新阅读你的代码，我想我发现了这个问题。在您的第一套开关语句和写KPI到LCD之后，您重置KPI。我相信您打算在这里重置kpi1，因为这个语句在命中if语句时使kpi总是等于零，所以它总是被评估为false。可能的意图是：



      以下为原文

    Re-reading your code, I think I found the issue.  After your first set of switch statements and writing kpi to LCD, you reset kpi.  
 

...
Lcd_Chr(1, 2, kpi) ; //Print key ASCII value on LCD
 
kpi = 0; //Reset key code variable
//wait for key code to be pressed and released
...

 
I believe you intend to be resetting kpi1 here, as this statement will make kpi always equal to zero when you hit your if statement, so it will always evaluate as false.  What was likely intended was:
 

...
Lcd_Chr(1, 2, kpi) ; //Print key ASCII value on LCD
 
kpi1 = 0; //Reset key code variable
//wait for key code to be pressed and released
...

有一个很简单的原因，你的测试总是失败。这条线：所以你在测试之前正在清除KPI！对编码风格也有一点建议。为什么要使用ASCII字符的十进制值，强迫您添加注释来说明它们是什么？这是更多的工作，而且容易出错。直接使用它们。例如



      以下为原文

    There's a very simple reason your test always fails.
This line:

 
So you are clearing kpi before you get to the test!
 
Also a little advice on coding style. Why use decimal values for ASCII characters, forcing you to add comments to say what they are? That is more work, and error prone.
Just use them directly. e.g.
    switch (kpi)
    {
      case 1: kpi = '7'; break;
      case 2: kpi = '4'; break;
      case 3: kpi = '1'; break;
      case 4: kpi = ' '; break; // Space
      case 5: kpi = '8'; break;
      case 6: kpi = '5'; break;
      case 7: kpi = '2'; break;
      case 8: kpi = '0'; break;
      case 9: kpi = '9'; break;
      case 10: kpi = '6'; break;
      case 11: kpi = '3'; break;
      case 12: kpi = '='; break;
      case 13: kpi = '/'; break;
      case 14: kpi = 'x'; break;
      case 15: kpi = '-'; break;
      case 16: kpi = '+'; break;
    }
 

OMG THX，现在我检查了代码，我看到我忘了把1的KPI重置KPI1，谢谢NJT。



      以下为原文

   
omg thx , now i checked the code and i see that i forgot putting 1 to kpi for resetting kpi1 , thanks NJT. 

或者在文件开始时，put:而不是switch语句，执行以下操作：（由您决定是否需要测试以确保永远不会读出数组的末尾。）p.s.您没有提到您正在运行这个PIC。如果您缺少RAM，通过将声明修改为:p.s.2不要在8位MCU上使用“in t”变量，在“char”或“unsigned char”的作用下。



      以下为原文

    Or this code will be smaller and faster
At the start of your file, put:
char lookup_table[] = " 741 8520963=/*-+";
and instead of the switch statement, do this:
    if (kpi <= 16)
        kpi = lookup_table[kpi];
(It's up to you to decide if the test is required to ensure you never read beyond the end of the array.)
 
 p.s. You didn't mention what PIC you are running this on.
If you're short on RAM, you can force the lookup table to stay in ROM by modifying the declaration to:
const char lookup_table[] = " 741 8520963=/*-+";
 
p.s.2
Don't use "int" variables on an 8 bit MCU where a "char" or "unsigned char" will do.

首先，您需要将两个小数转换为单个值。假设您首先为每个数字创建vraiables，以保存原始值，而不是ASCCI值。然后您只需要将它们组合如下：0和1位每次进入ASCII“0”和“1”。



      以下为原文

    First you need to convert your two decimals to a single value.
Assuming you first create vraiables for each digit, to hold the raw value, not the ASCCI value.
char tens;    //raw value of first digit 0-9
char ones;    //raw value of second digit 0-9
char total;    //total value 0-99
then you just need to combine them as follows:
    total = (tens * 10) + ones;
Then you need to extract the individual bits from the "total" variable one at a time, converting the zero and one bits into ASCII "0" and "1" each time.
Something like:
char counter;    //scratrch variable to count 8 bits
    for (counter = 8, counter != 0; counter--)    //loop 8 times
    {
        if (total & 0b10000000)
            lcd_putc('1');    //the bit was 1
        else
            lcd_putc('0');    //the bit was 0
        total <<= 1;    //shift the value in "total" left one bit
    }    //end of loop
 

此外，您在代码中有一个错误。我用我的方式说你需要乘法步骤的“原始”值。你使用的是ASCII值。我特别说过不要这样做。如果您知道您只有数字（“0”-“9”），那么可以通过使用0x0Fe.g.kpi&=0x0F简化ANDing来将ASCII转换为.；但是您有其他值，如“+”、“-”、“=”等，这将使所有这些复杂化。



      以下为原文

    Also, you have a mistake in that code. I went out of my way to say you need "raw" values for the multiplication step.
You are using the ASCII values. I specifically said to not do that.
If you know that you only have digits ("0" - "9"), then ASCII can be converted to raw by simplay ANDing with 0x0F
e.g.
kpi &= 0x0F;
but you have other values like "+", "-", "=" etc. which will complicate all this.
 

是的。就像我说的，如果你知道它只是从“0”到“9”的数字，那么它就可以正常工作。而且，我们只使用8位作为结果，所以不要尝试大于255的数字！



      以下为原文

    Yes.
As I said, if you know it's just digits from "0" to "9", then that will work fine.
Also, we're only using 8 bits for the result, so don't try a number bigger than 255 !
 

怎么了？我看不到LCD第二行的任何值。



      以下为原文

    /* KEYPAD INTERFACING WITH PIC16F877A */

char kpi; kpi1; kpi2; total1 ;
int i; remainder; total; binary; binary1;


char lookup_table[] = " 741 8520963=/*-+" ;


// Keypad module connections
char keypadPort at PORTD;
// End Keypad module connections

// LCD Module connections
***it LCD_RS at RB2_bit;
***it LCD_EN at RB3_bit;

***it LCD_D7 at RB7_bit;
***it LCD_D6 at RB6_bit;
***it LCD_D5 at RB5_bit;
***it LCD_D4 at RB4_bit;
// End LCD module connections

// LCD Pin direction
***it LCD_RS_Direction at TRISB2_bit;
***it LCD_EN_Direction at TRISB3_bit;

***it LCD_D7_Direction at TRISB7_bit;
***it LCD_D6_Direction at TRISB6_bit;
***it LCD_D5_Direction at TRISB5_bit;
***it LCD_D4_Direction at TRISB4_bit;
// End of LCD Pin direction

void main() {
Lcd_Init(); // Initialize LCD
Lcd_Cmd(_LCD_CLEAR); // Clear Display
Lcd_Cmd(_LCD_CURSOR_OFF); // Cursor Off
Lcd_Out(1,1,"BINARYCONVERSION"); // Write "KEYPAD INTERFACE" in the first row
delay_ms(500); // Delay of 0.5s
Lcd_Cmd(_LCD_CLEAR); // Clear Display
delay_ms(500); // Delay of 0.5s
Keypad_Init(); // Initialize Keypad
Lcd_Out(1,1,"PRESS A NUMBER"); // Write "PRESS A KEY" in the first row
delay_ms(500); // Delay of 0.5s
Lcd_Cmd(_LCD_CLEAR); // Clear Display
 do
  {
    kpi = 0; // Reset key code variable
    // Wait for key to be pressed and released
    do
      kpi = Keypad_Key_Click(); // Store key code in kpi variable


        
    while (!kpi);
    if (kpi <= 16) {
        kpi = lookup_table[kpi]; }

    Lcd_Chr(1, 2, kpi); // Print key ASCII value on Lcd

     kpi1= 0; // Reset key code variable
    // Wait for key to be pressed and released
    do
      kpi1 = Keypad_Key_Click(); // Store key code in kpi variable


    while (!kpi1);
     if (kpi1<= 16) {
        kpi1= lookup_table[kpi1];
        }


    Lcd_Chr(1, 3, kpi1); // Print key ASCII value on Lcd
    
    kpi2 = 0;
    do
      kpi2 = Keypad_Key_Click();
       while(!kpi2);
       if(kpi2<= 16){
       
    kpi2 = lookup_table[kpi2];
    }
    Lcd_Chr(1, 4, kpi2);
    kpi &= 0x0F;
    kpi1 &= 0x0F;
    kpi2 &= 0x0F;

    total = 0;
    total = (kpi*100) + (kpi1*10) + kpi2;
    binary = 0; i = 1;


    if ( total <=255 );{
do {

        remainder = (total % 2);
        total = (total/2);
        binary = binary + (remainder*i) ;
        i = (i*10);

        } while(total != 0);
       }



       ByteToStr(binary, total1);
       Lcd_Out(2, 1, total1);
       delay_ms(3000);
       Lcd_Cmd(_LCD_CLEAR); // Clear Display
    } while(1);
    



     }
What is wrong ? I can not see any value on LCD'S second row.

BytToStTo（）是做什么的？为什么要丢掉我为您编写的二进制输出代码，这样做可以正常工作，然后用thisWhites替换它？



      以下为原文

    What does ByteToStr() do?
 
Why did you throw away the binary output code I wrote for you, that would work, and replace it with this

do {
        remainder = (total % 2);
        total = (total/2);
        binary = binary + (remainder*i) ;
        i = (i*10);
        } while(total != 0);
       }
Which is rubbish.
Maybe if you added some comments to your code, explaining what it is trying to do, you will see it won't do anything useful.
 

因为我不能理解LCD-PUTC命令



      以下为原文

   


because i could not understand Lcd_putc command 

感谢您的帮助QHB！如果你生我的气，我很抱歉，我知道有时我不明白，因为我已经醒了20小时了，对不起。如果你不说kpi&=0X0F，我就不能。我编辑了第一篇文章，希望有人能利用这一点。



      以下为原文

   
Thanks for your helps qhb! if you mad on me i am sorry , i know sometimes i did not understand because i have been awake for 20hours , sorry .
if you did not say kpi&=0X0F i could not do. I editted first post , i hope someone can utilize from this.