Matrix Keypad routine

[mister_e]

Try something by yourself first.

1. Download the Keypad Include file,
2. Find LCDOUT in your manual,
3. Use the example I gave in POST #1 and you're almost half done if you replace HSEROUT with LCDOUT.

[Dennis]

Hi all

Please would somebody be so kind as to shed some light on the problem I am experiencing.

I am busy re-kindling my hobby and interest in PIC programming, I think these forums are an excellent resource, somehow all roads lead back here after many a google search and reading post after post and numerous articles.
After 3 weeks of late nights and sore eyes and a lot of reading later I have finally gotten to a stage where I have a functional (perhaps a very under-utilized PIC 18F4530).
After having blinked LED's and read switches and getting my LCD working I would like to implement a keypad as opposed to a bank of dip switches.

I am trying to implement the keypad.bas file submitted by mister_e (Thanks mister e ... your code looks fantastic, I'm dying to use it properly :-)

So here's where I'm at now....

I am trying to connect a 4 x 4 matrix keypad to my 18F4520 PIC.

Ultimately I would like to be able to be able to type in a number, end it with a # to signify completed input and then transmit the inputted number to another pic either wired or wireless.

The keypad layout is as follows.
my keypad matrix

1 2 3 A
4 5 6 B
7 8 9 C
* 0 # D


I have connected the keypad to the pic as follows.

Keypad PIC

Column 0 PortA.0
Column 0 PortA.1
Column 0 PortA.2
Column 0 PortA.
Row 0 PortC.0
Row 1 PortC.1
Row 2 PortC.2
Row 3 PortC.3

10K pullups set on column inputs
100 Ohm resistors in series with rows

When I have the above configured my LCD just produces blocks

If I remove either the pullups and/or the series resistors I just get "Key Value" 20 continuously appearing on the LCD and if I press a key on the keypad I get the "key Value" changing on the LCD but it is not the correct value according to my keypad.

I could also use the whole of Port A but when I tried it but had the same results :-(

Initially I tried to connect on PortB and had the same results, so I assumed it was because I was getting inputs from pin 39 and pin 40 of the pic where the PICkit 2 is connected for ICSP.

I have attached my code below.

Please could someone advise as to where I am going wrong or what I could look at to fix the problem !

I think it could be a possible CONFIG problem or coding issue in my code.

Any help would be greatly appreciated.

Kind regards

Dennis

'*************************************
'LCD code for 16 X 2  HD4x lcd
'*************************************

'Ocsillator selections here
OSCCON = $70            'Int CLK 8MHz
OSCTUNE.6 = 1           'PLL 4x
ADCON1= %00001111       '$0F = disable A/D converter
'END of oscillator selections


'Port IO directions and presets for port pins begin here
'TRISA = %11111111       'All pins are outputs
TRISA.0 = 1
TRISA.1 = 1
TRISA.2 = 1
TRISA.3 = 1
TRISB = %00000000           
'TRISC = %00000000
TRISC.0 = 1           
TRISC.1 = 1
TRISC.2 = 1
TRISC.3 = 1

TRISD = %00000000
TRISE.0 = 0
TRISE.1 = 0
TRISE.2 = 0
'End of Port IO directions and presets for port pins begin here

'timer/oscillator defines 
DEFINE OSC 32            '4x 8MHz
'END of timer/oscillator defines
                      
'variables begin here
myvar var byte

'LCD defines begin here   
DEFINE LCD_BITS 4 	'defines the number of data interface lines (4 or 8) 
DEFINE LCD_DREG PORTD 	'defines the port where data lines are connected to
DEFINE LCD_DBIT 4 	'defines the position of data lines for 4-bit interface (0 or 4)
DEFINE LCD_RSREG PORTD 	'defines the port where RS line is connected to
DEFINE LCD_RSBIT 2 	'defines the pin where RS line is connected to 
DEFINE LCD_EREG PORTD 	'defines the port where E line is connected to 
DEFINE LCD_EBIT 3 	'defines the pin where E line is connected 
DEFINE LCD_RWREG 0 	'defines the port where R/W line is connected to (set to 0 if not used)
DEFINE LCD_RWBIT 0 	'defines the pin where R/W line is connected to (set to 0 if not used)
DEFINE LCD_COMMANDUS 2000 	'defines the delay after LCDOUT statement 
DEFINE LCD_DATAUS 200 		'delay in micro seconds
'END of LCD DEFINES

'KEYPAD 4x4 defines begin here
      DEFINE KEYPAD_ROW        4        ' 4 ROW keypad       
      DEFINE KEYPAD_ROW_PORT   PORTC    ' ROW port = PORTB
      DEFINE KEYPAD_ROW_BIT    0        ' ROW0 = PORTB.4
      DEFINE KEYPAD_COL        4        ' 4 COL keypad
      DEFINE KEYPAD_COL_PORT   PORTA    ' COL port = PORTB
      DEFINE KEYPAD_COL_BIT    0        ' COL0 = PORTB.0
      DEFINE KEYPAD_DEBOUNCEMS 200      ' debounce delay = 200 mSec
      DEFINE KEYPAD_AUTOREPEAT 1        ' use auto-repeat feature  
'End of KEYPAD defines

'*********************Includes******

include "C:\PBP\SAMPLES\KeyPad.bas"
'Includes end here

'Code begins here
   Pause 500       ' Wait for LCD to startup
 
start:
@ READKEYPAD _myvar
lcdout $fe, 1
lcdout " Key Value = ",DEC2 myvar
goto start

[Dennis]

My problem in the previous post here is now solved.
The keypad is working.

But I now am trying to solve 2 more problems

1. I need the keypresses to reflect the correct label
My matrix is
1 2 3 A
4 5 6 B
7 8 9 C
* 0 # D

At the moment I get the following 1,2,3,4 as opposed to 1,2,3,A

2. I would like to capture a number of keystrokes as I type them in for example 135 completing input with a #
So the number stored will be the number decimal 135

Any help or suggestions will be most appreciated.

Kind regards

Dennis
For example keypress1

[Ioannis]

An idea would be to use the lookup command for your translation from numbers to numbers-ASCII conversion.

Now about the numbers to assebly in a byte. What is the range of your input?

0-255 or 0-999?

Ioannis

[Dennis]

Hi Ioannis

Thanks for the reply :-)
Lookup is already implemented and working .

My range would be anything really (inifinity ??) but I guess I could use 0 to 999

It's like dialling on a phone ... you dial the numbers and then press the dial button :-)

I want to type numbers in and then press the # key and * to backspace or clear last entry ...

Kind regards

Dennis

[Ioannis]

Well, if you go for the 999 then a 0-65535 is possible as the final result needs a word variable.

One idea untested is this:

array   var byte[5]
index   var byte
i       var byte
word_v  var word

'Get keypress
index=0

loop:
gosub key_read
if mykey=32 then loop 'No key press returns 32
array[index]=myvar
index=index+1
if index=5 then calculate_result
goto loop
...

caculate_result:
word_var=0:mult=10000
for i=index-1 to 0 step -1
    word_var=word_var*mult+array[i]
    mult=mult/10
next i
index=0
goto display_result

As there is the index counter, there is no need to press '#'. Numbers must be entered in 5 digit format, e.g. 00123.

Also there is no filter if the user keys in a number greater than 65535, in which case result will be of course wrong due to overflow.

Ioannis

[Dennis]

Hi Ioannis

Thank you for the code example... I'm just thinking that perhaps it would indeed be more practical to use 255 as the max number, in which case I would need to declare a byte as opposed to a word ...not so ?

Kind regards

Dennis