Single button function

[Melanie]

This appended example is the basis for the worlds most inaccurate clock.

It’s demonstrating ONE Button usage.

Press the Button momentarily and it will flip the display between 12/24 Hour Mode.

Press the Button for an extended time and it will jump into a Menu for you to set the time. Note the creative use of the CURSOR to indicate when a SET Function has been executed...

It’s just a ditty to show how you can do things with ONE Button.

And shows that code previously written (Olympic Timer) for a PIC16F876 can be quickly and easily ported and modified for a PIC16F628, or PIC16F628A or B or C...

It’s also a teaser for half a dozen recent (Timer) threads (and for a gentleman searching for an elapsed timer – hint – hint – somebody nudge him to look at this thread!!!!) to show what can be done with 10 minutes worth of code, half a bucket of Cafe Nero's finest and a plastic straw...

	'
	'	Buttons.bas
	'	---------------
	'	by Melanie 
	'	written on a Laptop in a lunchbreak in a Cafe Nero
	'	in Londons famous Regent Street... 7th June 2006
	'
	'	A simple demonstrator as to what can be done
	'	with just ONE Button and an LCD...
	'	Some Code stolen from OLYMPIC TIMER
	'

	'
	'	Device Programming Options
	'	--------------------------
	@ DEVICE pic16F628, INTRC_OSC_NOCLKOUT
					' System Clock Options	
	@ DEVICE pic16F628, WDT_ON	' Watchdog Timer
	@ DEVICE pic16F628, PWRT_ON	' Power-On Timer
	@ DEVICE pic16F628, BOD_ON	' Brown-Out Detect
	@ DEVICE pic16F628, MCLR_OFF	' Master Clear Options (Internal)
	@ DEVICE pic16F628, LVP_OFF	' Low-Voltage Programming
	@ DEVICE pic16F628, CPD_OFF	' Data Memory Code Protect
	@ DEVICE pic16F628, PROTECT_OFF	' Program Code Protection

	'
	'	Hardware Defines
	'	----------------
		'
		' 	LCD Display
		'	-----------
	Define LCD_DREG PORTB		' Port for LCD Data
	Define LCD_DBIT 4		' Use upper 4 bits of Port
	Define LCD_RSREG PORTB		' Port for RegisterSelect (RS) bit
	Define LCD_RSBIT 3		' Port Pin for RS bit
	Define LCD_EREG PORTB		' Port for Enable (E) bit
	Define LCD_EBIT 2		' Port Pin for E bit
	Define LCB_BITS 4		' Using 4-bit bus
	Define LCD_LINES 2		' Using 2 line Display
	Define LCD_COMMANDUS 2000	' Command Delay (uS)
	Define LCD_DATAUS 50		' Data Delay (uS)
		'
		'	Buttons
		'	-------
	MyButton var PortB.0

	'
	'	Software Defines
	'	----------------
	AMPMFlag var BYTE		' Flag for 12/24 Hour Mode 0=24, 1=12
					' - Yes I know it's a BYTE but I can't be bothered
	ButtonPress var BYTE		' Button Counter Variable
	DataA var BYTE
	Hours var BYTE
	Hundredths var BYTE
	MenuStep var BYTE		' Status Indicator for Menu Display
	Minutes var BYTE
	Seconds var BYTE
	TMR1Cal	var BYTE		' Timer Calibration Value
	TMR1CalAR var BYTE		' Timer Advance/Retard Indicator
	TMR1RunOn var WORD		' variable holding TMR1 Run-On value


	'
	'	EEPROM Settings
	'	---------------
	Data @0,0			' Advance/Retard Indicator
	Data 0				' Calibration Value
	Data 0				' 12/24 Hour Flag

	'
	'	Software Constants
	'	------------------
	LongPress con 20		' Change this value for desired SET 
					' function trip-point in 50mS steps
					' Currently set for 1 Second
	TMR1CalMax con 100		' Maximum adjustment (+/-100uS per 10mS interrupt)
	TMR1Preset con $D910		' 10mS Timer Reload value, offset by 20uS
					' to allow for TMR1 Setting Calculations
	'
	'	Initialise PIC
	'	--------------
	TRISA=%00000000			' PortA I/O Configuration
	TRISB=%00000001			' PortB I/O Configuration
	CMCON=%00000111			' Comparators OFF
	OPTION_REG.7=0			' Enable weak Pull-Ups (used for PressButton)

	'
	'	Initialise Main Program
	'	-----------------------
	Pause 2000			' Timeout for LCD Hardware to wake-up...
	Read 0,TMR1CalAR		' Read Calibration Advance/Retard Indicator
	Read 1,TMR1Cal			' Read Calibration Value
	Read 2,AMPMFlag			' It's what it says...
	Hundredths=0			' Reset Timer Counter variables
	Seconds=0
	Minutes=0
	Hours=0
		'
		'	Initialise TMR1 Interrupts
		'	--------------------------
	Gosub SetTimer			' Set the Timer for next 10mS Interrupt
	On Interrupt goto TickCount
	PIE1.0=1			' Enable TMR1 Interrupts
	INTCON.6=1			' Enable all unmasked Interrupts
	INTCON.7=1			' Enable Global Interrupts
DisplayRestart:
	LCDOut $FE,1			' Clear Display
	'
	'	Main Program Loop
	'	-----------------
	Enable
DisplayLoop:
	LCDOut $FE,$0C
	If AMPMFlag=0 then
		'
		'	Here we have got a 24 Hour Clock Display
		'	----------------------------------------
		LCDOut $FE,$84,DEC2 Hours,":",DEC2 Minutes,":",DEC2 Seconds
		else
		'
		'	and here we have a 12 Hour Clock Display
		'	----------------------------------------
		LCDOut $FE,$82
		DataA=Hours
		If DataA=0 then DataA=12
		If DataA>12 then DataA=DataA-12
		If DataA<10 then LCDOut " "
		LCDOut #DataA,":",DEC2 Minutes,":",DEC2 Seconds," "
		If Hours>11 then 
			LCDOut "PM"
			else
			LCDOut "AM"
			endif
		endif
	'
	'	Check For Button Press
	'	----------------------
	Gosub GetButton
		'
		'	Toggle 24 Hour Mode
		'	-------------------
	If ButtonPress=1 then
		AMPMFlag=AMPMFlag^1
		Write 2,AMPMFlag
		Goto DisplayRestart
		endif
	If ButtonPress<>2 then goto DisplayLoop
	Disable
	'
	'	Setup Mode
	'	----------
	LCDOut $FE,1,"Set Time Please:"
	LCDOut $FE,$C4,DEC2 Hours,":",DEC2 Minutes,":",DEC2 Seconds,$FE,$C5
	MenuStep=0
MenuLoop:
	Gosub GetButton
		'
		'	SET Mode
		'	--------
	If ButtonPress=2 then
		MenuStep=MenuStep+1
		If MenuStep=3 then
			LCDOut $FE,1,$FE,$83,"Thank You",$FE,$C0,"Have a Nice Day"
			Pause 2000
			Goto DisplayRestart
			endif
		endif
	If ButtonPress=1 then
		'
		'	Hours
		'	-----
		If MenuStep=0 then
			Hours=Hours+1
			If Hours>23 then Hours=0
			LCDOut $FE,$C4,DEC2 Hours
			endif
		'
		'	Minutes
		'	-------
		If MenuStep=1 then
			Minutes=Minutes+1
			If Minutes>59 then Minutes=0
			LCDOut $FE,$C7,DEC2 Minutes
			endif
		'
		'	Seconds
		'	-------
		If MenuStep=2 then
			Seconds=Seconds+1
			If Seconds>59 then Seconds=0
			LCDOut $FE,$CA,DEC2 Seconds
			endif
		endif
		'
		'	Ensure Cursor is in a nice place...
		'	--------------------------------
	LCDOut $FE,$0E
	If MenuStep=0 then 
		LCDOut $FE,$C5
		else
		If MenuStep=1 then
			LCDOut $FE,$C8
			else
			LCDOut $FE,$CB
			endif
		endif
	Goto MenuLoop

	'
	'	Subroutine weighs-up users finger
	'	in multiples of 50mS
	'	Constant LONGPRESS determines boredom level
	'	-------------------------------------------
	'	on Exit...
	'	ButtonPress=0 - No Press
	'	ButtonPress=1 - Short Press
	'	ButtonPress=2 - Long Press
GetButton:
	ButtonPress=0
	While MyButton=0
		If ButtonPress<255 then ButtonPress=ButtonPress+1
		Pause 50 ' This is also our Debounce value
		If ButtonPress=>LongPress then LCDOut $FE,$0F
		Wend
	If ButtonPress>0 then
		If ButtonPress=>LongPress then 
			ButtonPress=2
			else
			ButtonPress=1
			endif
		endif
	Return

	'
	'	Subroutine Loads TMR1 values
	'	============================
SetTimer:
	T1CON.0=0			' Stop the Clock
	TMR1RunOn.Highbyte=TMR1H	' Load the Run-On (Over-Run) value (if any)
	TMR1RunOn.Lowbyte=TMR1L
	TMR1RunOn=TMR1Preset+TMR1RunOn	' Calculate the New (adjusted) value for TMR1
	If TMR1CalAR=0 then		' Calibration ADVANCE (add) or RETARD (subtract)
		TMR1RunOn=TMR1RunOn+TMR1Cal
		else
		TMR1RunOn=TMR1RunOn-TMR1Cal
		endif
	TMR1H=TMR1RunOn.Highbyte		' Save new values to TMR1
	TMR1L=TMR1RunOn.Lowbyte
	T1CON.0=1			' Restart the Clock
	PIR1.0=0			' Reset TMR1's Interupt Flag
	Return

	'
	'	Timer Interrupt Handler
	'	=======================
TickCount:
	Gosub SetTimer			' Set the Timer for next 10mS Interrupt
	Hundredths=Hundredths+1		' Increment 10mS Seconds Counter
	If Hundredths>99 then
		Hundredths=0
		Seconds=Seconds+1
					' Increment the Seconds
		If Seconds>59 then
			Seconds=0
			Minutes=Minutes+1
					' Increment the Minutes
			If Minutes>59 then
				Minutes=0
				Hours=Hours+1
					' Increment the Hours
				If Hours>23 then Hours=0
				endif
			endif
		endif
	Resume

	End