pic programming 16f84......need help...

[tcp]

hi,i'm doing a project using pic(16f84) to control a dc motor. there are 3 position sensors....i have set three switch to input and my sensors should detect the position accordingly...for example if i press switch 1 it should rotate until position sensor 1 is on then it will stop the motor. the problem is i use port b to set all my inputs RB0-RB2(switch) and RB3-RB5(sensors)....how do i write the program so that when both are match,it will stop the motor....i have try to use BTFSS and ANDLW but i stuck...due to the numbers of bit involved i,m stucked... can i group a number of bits ANDLW with a group of bits??for example from port b pin 0-2 a group and again port b pin 3-5 a group i'm still a newbies in pic programming.....pls help me.....thanks

 

[Optikon]

hi,i'm doing a project using pic(16f84) to control a dc motor. there are 3 position sensors....i have set three switch to input and my sensors should detect the position accordingly...for example if i press switch 1 it should rotate until position sensor 1 is on then it will stop the motor. the problem is i use port b to set all my inputs RB0-RB2(switch) and RB3-RB5(sensors)....how do i write the program so that when both are match,it will stop the motor....i have try to use BTFSS and ANDLW but i stuck...due to the numbers of bit involved i,m stucked... can i group a number of bits ANDLW with a group of bits??for example from port b pin 0-2 a group and again port b pin 3-5 a group i'm still a newbies in pic programming.....pls help me.....thanks

Post this in the microcontroller section of this board..
or maybe Nigel has a quick answer for you..
:wink:

 

[tcp]

thanx a lot....i'll post it rite away.....

 

[Nigel Goodwin]

hi,i'm doing a project using pic(16f84) to control a dc motor. there are 3 position sensors....i have set three switch to input and my sensors should detect the position accordingly...for example if i press switch 1 it should rotate until position sensor 1 is on then it will stop the motor. the problem is i use port b to set all my inputs RB0-RB2(switch) and RB3-RB5(sensors)....how do i write the program so that when both are match,it will stop the motor....i have try to use BTFSS and ANDLW but i stuck...due to the numbers of bit involved i,m stucked... can i group a number of bits ANDLW with a group of bits??for example from port b pin 0-2 a group and again port b pin 3-5 a group i'm still a newbies in pic programming.....pls help me.....thanks

You can use the shift commands (RRF and RLF) to align the bits in the two values (move them to variables first). Once they are aligned use ANDLW to mask off any unused bits, then use XORWF or SUBWF to compare them.

 

[tcp]

....thanx a lot.....cheeeers~~!