rimaaratri
Newbie level 2
![Newbie level 2](/styles/images/ranks/alevel2.gif)
I new to use PIC16F877a, now I'm tried the interface between the LCD 16x2 and keypad 4x4. lcd at portD and keyad at PORTB, but my keypad is not working, i work with disable LVP conditions and my program write in mikroC. my question what was wrong in my project?
Code C - [expand] 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 unsigned short kp, cnt, oldstate = 0; char txt[6]; // Keypad module connections char keypadPort at PORTB; // End Keypad module connections // LCD module connections sbit LCD_RS at RA5_bit; sbit LCD_RW at RA4_bit; sbit LCD_EN at RA3_bit; sbit LCD_D4 at RD4_bit; sbit LCD_D5 at RD5_bit; sbit LCD_D6 at RD6_bit; sbit LCD_D7 at RD7_bit; sbit LCD_RS_Direction at TRISA5_bit; sbit LCD_RW_Direction at TRISA4_bit; sbit LCD_EN_Direction at TRISA3_bit; sbit LCD_D4_Direction at TRISD4_bit; sbit LCD_D5_Direction at TRISD5_bit; sbit LCD_D6_Direction at TRISD6_bit; sbit LCD_D7_Direction at TRISD7_bit; // End LCD module connections void main() { ADCON1 = 0X0F; //All A to D pin on PortA to digital CMCON = 0X07; //Disable comparators TRISA4_bit = 1; OPTION_REG.B7 = 0; TRISB = 1; PORTB = 0; TRISD = 0; PORTD = 0; TRISA = 0; PORTA = 0; cnt = 0; // Reset counter Keypad_Init(); // Initialize Keypad 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, 10, " "); } WordToStr(cnt, txt); // Transform counter value to string Lcd_Out(2, 10, txt); // Display counter value on LCD } while (1); }