Hi there,
I am still quite new to this.
I have a 4 X 4 keypad... has 8 pins. I am attaching 4 pins to RB1 - RB4 and the other 4 pins to RD4 - RD7.
I intend to force an interupt on the portB via the first 4 pins.
What I need to know is... if I enable weak pullups on say RD4 - RD7 and a user presses a button will the PIC register a true ON signal on the D port?
Of course there will be a port value of 1 on port B but given that portD pin has a weak pullup already will it register that current is moving.. and change that port value from 0 to 1.
I need to test both portB and portD to determine which button has been pressed...
In another way can I use weak pullups to allow current to flow if a key has been pressed and while the key is not pressed does that port pin with the weak pullup have a value of "0"?
Hope I have explained this OK...
Kind Regards
Simon
I am still quite new to this.
I have a 4 X 4 keypad... has 8 pins. I am attaching 4 pins to RB1 - RB4 and the other 4 pins to RD4 - RD7.
I intend to force an interupt on the portB via the first 4 pins.
What I need to know is... if I enable weak pullups on say RD4 - RD7 and a user presses a button will the PIC register a true ON signal on the D port?
Of course there will be a port value of 1 on port B but given that portD pin has a weak pullup already will it register that current is moving.. and change that port value from 0 to 1.
I need to test both portB and portD to determine which button has been pressed...
In another way can I use weak pullups to allow current to flow if a key has been pressed and while the key is not pressed does that port pin with the weak pullup have a value of "0"?
Hope I have explained this OK...
Kind Regards
Simon