Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Using pic16f877a to scan 4x3 keypad and display each pressed key on 7segment display

Status
Not open for further replies.

GENGE

Newbie level 2
Newbie level 2
Joined
Dec 13, 2012
Messages
2
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Visit site
Activity points
1,304
I need help please i want to scan 4x3 keypad and display the pressed key on seven segment display.
Required is c source code and proteus simulations.
Your help please , this is my project.
 

See this example its MikroE example for 4x4 keypad but show result on LCD, you can adjust to your needs:

Code:
/*
 * Project name:
     Keypad_Test (Demonstration of usage of the Keypad Library)
 * Copyright:
     (c) MikroElektronika, 2012.
 * Revision History:
     20080930:
       - initial release;
     20111012;
       - revision (JK);
 * Description:
      A simple example of using the keypad library for mikroC PRO for PIC.
      It supports keypads with 1..4 rows and 1..4 columns. The code being 
      returned by the Keypad_Key_Press() and Keypad_Key_Click() functions is
      in range from 1..16. In this example, the code returned by the keypad 
      library functions is transformed into ASCII codes [0..9,A..F]. 
      In addition, a small single-byte counter displays in the second LCD row 
      number of key presses.
 * Test configuration:
     MCU:             PIC18F45K22
                      http://ww1.microchip.com/downloads/en/DeviceDoc/41412D.pdf
     Dev.Board:       EasyPIC7
                      http://www.mikroe.com/easypic/
     Oscillator:      HS-PLL, 32.00000 MHz
     Ext. Modules:    ac:Keypad_4x4_Board at PORTC, LCD 2x16
     SW:              mikroC PRO for PIC
                      http://www.mikroe.com/mikroc/pic/
 * NOTES:
     - Pull-down PORTC (PortC three-state switch).
     - Turn on LCD backlight SW4.6 (board specific)
 */
 
unsigned short kp, cnt, oldstate = 0;
char txt[6];

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

// LCD module connections
sbit LCD_RS at LATB4_bit;
sbit LCD_EN at LATB5_bit;
sbit LCD_D4 at LATB0_bit;
sbit LCD_D5 at LATB1_bit;
sbit LCD_D6 at LATB2_bit;
sbit LCD_D7 at LATB3_bit;

sbit LCD_RS_Direction at TRISB4_bit;
sbit LCD_EN_Direction at TRISB5_bit;
sbit LCD_D4_Direction at TRISB0_bit;
sbit LCD_D5_Direction at TRISB1_bit;
sbit LCD_D6_Direction at TRISB2_bit;
sbit LCD_D7_Direction at TRISB3_bit;
// End LCD module connections

void main() {
  cnt = 0;                                 // Reset counter
  Keypad_Init();                           // Initialize Keypad                              
  ANSELB = 0;                              // Configure AN pins as digital I/O
  ANSELC = 0;
  Lcd_Init();                              // Initialize LCD
  Lcd_Cmd(_LCD_CLEAR);                     // Clear display
  Lcd_Cmd(_LCD_CURSOR_OFF);                // Cursor off
  Lcd_Out(1, 1, "1");
  Lcd_Out(1, 1, "Key  :");                 // Write message text on LCD
  Lcd_Out(2, 1, "Times:");

  do {
    kp = 0;                                // Reset key code variable

    // Wait for key to be pressed and released
    do
      // kp = Keypad_Key_Press();          // Store key code in kp variable
      kp = Keypad_Key_Click();             // Store key code in kp variable
    while (!kp);
   // Prepare value for output, transform key to it's ASCII value
    switch (kp) {
      //case 10: kp = 42; break;  // '*'   // Uncomment this block for keypad4x3
      //case 11: kp = 48; break;  // '0'   
      //case 12: kp = 35; break;  // '#'
      //default: kp += 48;

      case  1: kp = 49; break; // 1        // Uncomment this block for keypad4x4
      case  2: kp = 50; break; // 2
      case  3: kp = 51; break; // 3
      case  4: kp = 65; break; // A
      case  5: kp = 52; break; // 4
      case  6: kp = 53; break; // 5
      case  7: kp = 54; break; // 6
      case  8: kp = 66; break; // B        
      case  9: kp = 55; break; // 7
      case 10: kp = 56; break; // 8
      case 11: kp = 57; break; // 9
      case 12: kp = 67; break; // C
      case 13: kp = 42; break; // *
      case 14: kp = 48; break; // 0
      case 15: kp = 35; break; // #
      case 16: kp = 68; break; // D

    }

    if (kp != oldstate) {                  // Pressed key differs from previous
      cnt = 1;
      oldstate = kp;
      }
    else {                                 // Pressed key is same as previous
      cnt++;
      }

    Lcd_Chr(1, 10, kp);                    // Print key ASCII value on LCD

    if (cnt == 255) {                      // If counter varialble overflow
      cnt = 0;
      Lcd_Out(2, 8, "   ");
      }

    ByteToStr(cnt, txt);                   // Transform counter value to string
    Lcd_Out(2, 8, txt);                   // Display counter value on LCD
  } while (1);
}

- - - Updated - - -

Check this project :

http://www.piccircuit.com/shop/pic-code/41-tutorial-5a-4x3-keypad-demo.html
 
Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top