How to use an Interrupt to drive a menu on 16f88

[Tom Gonser]

This is EXACTLY what I was looking for.... I just need to know if I can use RB4 instead of RB0.. and where to find the % mapping for that!!!

Tom

[Tissy]

Tom,

As far as i'm aware (without looking at the Data Sheet for your PIC), this PIC has only one inturrupt line, RB0. RB4 is used for MCLR which is a RESET line.

To be sure go to Microchips WEB site and get the latest Datasheet.

Why don't you want to use RB0?

Hope this helps,

Steve

[mister_e]

you probably have Interrupt on PORTB change just check the PORTB.4 status in the interrput handler and you should be in business.

Just be careful when you program your PIC.. disable MCLR to make it RB4

[Tom Gonser]

Ahhh! OK! I thought interrupts were things you could assign to any pin, that is all. I was looking to closely at this to notice that RB0 had an assigned function 'INT'..

I have a proto board made up that runs rb4 and rb5 off to a post for easily attaching pins to - the reason I wanted to use RB4.. I can tie off to RB0 but it is a little soldering now, that's all. Btw, RB0 is pin #6 on the F88. Pin 4 is MCLR.

One other thing - 'enable pull up resistor' - do I need to tie a 1K ohm resistor from VDD to the pin also, or is this a software switch?

Tom

[Tissy]

Ah, now i have learnt something !!

Steve, so in the example code i have posted, what part needs to be changed to reflect the different PORT for the Inturrupt.

Cheers,

Steve

[Tom Gonser]

So.... Is there some way to listen for interrups on RB4? Or is the chip designed to have interrupts come in vai RB0?

Thanks,
Tom