How to use push button function with PIC18F452 ?

[peachgirl]

Is there some one can tell me how to use interrupt for "push bouton",
The #INT_BUTTON is not defined in the 18F452.h, the data bus I use for the button is PORTD:

[inservi]

Hello,

For a button, there are tree external interrupt available on port B0, B1 and B3.
You need to use INT_EXT for B0, INT_EXT1 for B1 and INT_EXT2 for B2.

You can not use port D for this kind of interrupt.

Look at the EX_WAKUP.C for an example.

Best regards,
dro
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[peachgirl]

thank you very much

[peachgirl]

maybe, i have not explicatied well my question,
in fact, I want to use a interrupt for a keyboard.
I can also use the way that you said?
thank you

[inservi]

Hello,

First I need to correct a typing error. The three (not 'tree') external interrupts are on port B0, B1 and B2 not 'B3'.

These interrupts can of course be used for a keyboard.
A keyboard is composed of several buttons. If you can make a matrix of 3 by x, then three interrupts will be enough.

If you are disturbed by the EX_WAKUP.C example, keep in mind that is only a sample for the external interupts use.

Sorry for my bad English.

Best regards,
dro
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in médio virtus

[inservi]

I just find a similar topic: http://www.ccsinfo.com/forum/viewtopic.php?t=30900

With a small sample code at the end.

dro
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[peachgirl]

thank you very very much

I find, my B0,B1,B2 have been used for other interrupts.

[inservi]

Hello,

You can use RB interrupt for B4-B7 pins changes. As there is only one interrupt for 4 pins, you need to compare the state of each pins with previous state for know which pin was changed and activated the interrupt. You can then make a 4 x n matrix.

I hope that you not yet using these pins.

dro
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in médio virtus