4x4 Keypad with PIC18F46K22

[VeikoK]

Hi

I'm struggling with 4x4 keypad (PIC18F46K22).
At beginning I was able to get it work, based on example on HELP. But after I add some more code around it... Keypad stops to work (I have there one I2C bus on RC3, RC4 and 2 rotary encoders some where on Port A and B pins). I didn't notice when exactly (after which change).

Then I decide to "go back" and start it again from scratch, just to test Keypad only but no success...
Display is working but keypad not.

Code is below (compared to example, there is some LCD pins are different)

Probably it's related to some config bits, but which ones .

Thanks in advance

Code: Select all

program Keypad_Test
dim kp, cnt, oldstate as byte
    txt as char[7]

' Keypad module connections
dim keypadPort as byte at PORTD
' End Keypad module connections

' Lcd module connections
dim LCD_RS as sbit at RC2_bit
    LCD_EN as sbit at RC5_bit
    LCD_D4 as sbit at RB0_bit
    LCD_D5 as sbit at RB3_bit
    LCD_D6 as sbit at RB1_bit
    LCD_D7 as sbit at RB2_bit

    LCD_RS_Direction as sbit at TRISC2_bit
    LCD_EN_Direction as sbit at TRISC5_bit
    LCD_D4_Direction as sbit at TRISB0_bit
    LCD_D5_Direction as sbit at TRISB3_bit
    LCD_D6_Direction as sbit at TRISB1_bit
    LCD_D7_Direction as sbit at TRISB2_bit
' End Lcd module connections

main:
  ANSELB  = 0
  ANSELC  = 0
  oldstate = 0
  cnt = 0                             ' Reset counter
  
  'Port D
  ANSELD  = 0                          ' Configure AN pins as digital I/O

  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, "Key  :")             ' Write message text on LCD
  Lcd_Out(2, 1, "Times:")

  while TRUE

    kp = 0                            ' Reset key code variable

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

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

    end select

    if (kp <> oldstate) then        ' Pressed key differs from previous
      cnt = 1
      oldstate = kp
    else                            ' Pressed key is same as previous
      Inc(cnt)
    end if
    Lcd_Chr(1, 10, kp)              ' Print key ASCII value on LCD

    if (cnt = 255) then             ' If counter varialble overflow
      cnt = 0
      Lcd_Out(2, 10, "     ")
    end if

    WordToStr(cnt, txt)             ' Transform counter value to string
    Lcd_Out(2, 10, txt)             ' Display counter value on LCD
  wend
end.

[filip]

Hi,

Please declare the PORTD as digital, like this :

Code: Select all

  ANSELB  = 0
  ANSELC  = 0
  ANSELD  = 0

Regards,
Filip.

[VeikoK]

Hi,

Please declare the PORTD as digital, like this :

Code: Select all

  ANSELB  = 0
  ANSELC  = 0
  ANSELD  = 0

Hi Filip

I did that. It's visible also in code.
I added to WHILE loop 2 LCD_OUT's

Code: Select all

LCD_Out(1,1,"1")
kp = Keypad_Key_Click()
LCD_Out(1,1,"2")

When program starts then 1 & 2 are flashing on LCD (as expected). After preessing I some key in keyboard "1" is frozen to screen. Looks like program froze on that point (does not return from Keypad_Key_Clik() )

[VeikoK]

I was able to solve the issue.

At beginning I thought the problem is in code or pic configuration. Then I recall that some time ago I put PIC to socket wrong way (couple of times) and then I notice visibly higher current consumption (power supply start to limit the current). After I recall it I start to suspect, might be I burn out the PIC then (portd). And I order a bunch of new pics. Today I receive them and after the first test.... end result was the same. Didn't work.
Then I notice that time to time I can see change in LCD (pressed key number) ... specially after (or during) I measured I/O's with scope. ... After that I measured one row signal with scope and on same time I pressed keys.... it was working. What I discover.... 10k resistors (on portd0...3), 1 has ~1+M resistance and 3 has infinite resistance (SMD 0805 size). Might be they burned (or half burned) when I put PIC "upside down" in to the socket.

To be an idiot is very time consuming.

[filip]

Hi,

I'm glad that you have solved this issue.

Regards,
Filip.