'  ###########  start  ###########
'  pic:PIC16C84
'  ###########   end   ###########
'
' ******************************************************************
' Binary Clock
' 2014-09-23 (c) Paolo Iocco
' ******************************************************************
'
' Circuit diagram
' ---------------
'               +--\/--+            
'   Hour<-------|1°  18|-------->Min
'   t_hour>-----|2   17|-------->Sec
'   t_min >-----|3   16|<--------H   
'  +5V--+50K+-->|4   15|<--------H = 4 MHz chrystal+ capacitors
'   GND-------->|5   14|<--------+5V
'   Bit1<-------|6   13|-------->t_set
'   Bit2<-------|7   12|-------->Bit7
'   Bit3<-------|8   11|-------->Bit6  
'   Bit4<-------|9   10|-------->Bit5   
'               +------+ 
'
' ******************************************************************

#Chip 16C84, 4
#Config OSC = XT, WDT = OFF, PWRTE = ON, CP = OFF

#define l_sec PORTA.0
#define l_min PORTA.1
#define l_hour PORTA.2
#define t_set PORTB.7
#define t_hour PORTA.3
#define t_min PORTA.4
'#define Timer_Charge 130 '255-125 on a 4MHz Clock
#define Timer_Charge 124 '255-131 on a 4.19MHz Clock

dir PORTB out
dir l_sec out
dir l_min out
dir l_hour out
dir t_set in
dir t_hour in
dir t_min in

dim milliseconds as byte
dim Timer_1 as byte
dim Timer_10 as byte
dim _hour as byte
dim _min as byte
dim _sec as byte

Startup:
_hour=0
_min=0
_sec=0
milliseconds=0
Timer_10=100 '1s
Timer_1=10 '10ms
InitTimer0 Osc, PS0_8
TMR0=Timer_Charge

Interrupts:
On Interrupt Timer0Overflow Call Tmr0_ISR

Loop:
do
	if Timer_1=0 then
		Timer_1=10
		'controllo del tasto premuto
	end if
	if Timer_10=0 then
		Timer_10=100 '1s period
		Inc_Clock 'icrements evrey 1s
	end if
	Led_Display
loop

Sub Tmr0_ISR
	'on Timer0 Overflow (IRQ on transition 255 to 0) 
    TMR0=Timer_Charge 'reset counter --> Timer_Charge
	if Timer_1>0 then Timer_1 --
	milliseconds ++
    if milliseconds=10 then
  		if Timer_10>0 then Timer_10 --
  		milliseconds=0
    end if
End Sub

Sub Inc_Clock
	'sub to increment _sec, _min and _hour
	_sec ++
	if _sec >59 then
		_sec=0
		_min ++
		if _min >59 then
			_min=0
			_hour ++
			if _hour >23 then
				_hour=0
			end if
		end if
	end if
End Sub

Sub Led_Display
	'Sub per visualizzare le tre variabili
	set l_sec on
	set l_min off
	set l_hour off
	PORTB = _sec
	set l_sec off
	set l_min on
	set l_hour off
	'PORTB = _min
	set l_sec off
	set l_min off
	set l_hour on
	'PORTB = _hour
End Sub