Matrix Keypad routine

[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

[Ioannis]

Yes, that is correct. Rest applies of course.

But don't be afraid of the word variable!

Ioannis

[Dennis]

Hi all

The keypad code has been working very well ! Thanks mister_e!

Initially I had to wire alter the wiring to the keypad to the PIC to get things working now in order to match the header pins for PORT B on a dev board I am building I need to alter the include file somehow to match my keypad.
I was hoping someone could point me in the right direction for this or tell me where to change the code to match the desired pin configuration.
Here is what I have now:

EXISTING CONFIG (WORKING)
-------------------------

Columns Rows
______________ _____________
Keypad 7 6 5 4 3 2 1 0

PIC B4 B5 B6 B7 B0 B1 B2 B3

Here's what I would like to be
DESIRED CONFIG
--------------

Columns Rows
______________ _____________
Keypad 7 6 5 4 3 2 1 0

PIC B7 B6 B5 B4 B3 B2 B1 B0



I would appreciate any help/info

Kind regards

Dennis

[Dennis]

Check the attached file

Dennis