switches & LEDs ... my first attempt

[Melanie]

So the requirement is as long as the switch is closed you want the respective LED to blink, but they blink at different rates?

[Melanie]

Your request is slightly more complex than you first imagine, because if the PIC is busy timing one LED, it can't really be attending to the other. So we have to do a bit of magic...

Here I've changed the Labels to make association between Switches, LED's, Constants and Variables more readable.

Like Clint Eastwood said in the Dirty Harry films... "Every man has to know his limitations". Now this applies equally to PICs and programs as well. Here, in our example program, the limitation I've set, is that everything happens in multiples of 10mS... but the flip side is that with this method you can add as many LED's and Switches as you have pins on your PIC and each can have different timing rates...

	SwitchA var PORTA.0 	' switch on porta.0
	SwitchB var PORTA.3	' switch on portb.0

	LedA VAR PORTB.0	' LED on portb.0
	LedB VAR PORTB.5 	' LED on PortB.5

	TRISA.0 = 1 		' porta.0 is now an input
	TRISA.3 = 1 		' Porta.3 is now an input
	TRISB.0 = 0 		' Portb.0 is left
	TRISB.5 = 0 		' Portb.5 is STB

	CMCON=%00000111		' ensures PortA is in Digital Mode

	LedABlinkRate con 10	' Blink Rate in Steps of 10mS (10=100mS)
	LedBBlinkRate con 33	' Blink Rate in Steps of 10mS (33=330mS)

	LedACounter var BYTE	' Counter for LedA
	LedBCounter var BYTE	' Counter for LedB

	Low LedA		' Startup with all LEDs OFF
	Low LedB
	LedACounter=0		' Startup with all Counters OFF
	LedBCounter=0

Main:
	If SwitchA=0 THEN 	' Closing SwitchA blinks LedA
		If LedACounter=0 then
			Toggle LedA
			LedACounter=LedABlinkRate
			else
			If LedACounter>0 then LedACounter=LedACounter-1
			endif
		else
		LedACounter=0
		low LedA
		endif

	If SwitchB=0 THEN 	' Closing SwitchB blinks LedB
		If LedBCounter=0 then
			Toggle LedB
			LedBCounter=LedBBlinkRate
			else
			If LedBCounter>0 then LedBCounter=LedBCounter-1
			endif
		else
		LedBCounter=0
		low LedB
		endif

	Pause 10
	Goto Main

	end

Just added a minor change (zeroing LedACounter and LedBCounter in the main loop), so if you missed it first time, copy the code again.