Etepic

'****************************************************************
'*  Name    : UNTITLED.BAS                                      *
'*  Author  : Dwight and others                                *
'*  Notice  : Copyright (c) 2013 [select VIEW...EDITOR OPTIONS] *
'*          : All Rights Reserved                              *
'*  Date    : 11/29/2013                                        *
'*  Version : 1.0                                              *
'*  Notes  :  PIC12F1822                                                *
'*          :                                                  *
'****************************************************************
#CONFIG
  __CONFIG _CONFIG1, _FCMEN_OFF & _FOSC_INTOSC & _WDTE_SWDTEN & _MCLRE_OFF & _CP_OFF & _IESO_OFF & _BOREN_OFF & _PWRTE_OFF
  __CONFIG _CONFIG2, _LVP_OFF
#ENDCONFIG

DEFINE  OSC 8                'tell picbasic what speed the oscillator is

'INCLUDE "DT_INTS-14.bas"    ' 
'INCLUDE "ReEnterPBP.bas"    ' Include if using PBP interrupts

OSCCON = %01110010        
                        '0 = 4x PLL is disabled
                        ' 1110 = 8 MHz 
                        '    0 = unused
                        '      1X = Internal oscillator


ANSELA = %00000100        'make port A.2 is analog
TRISA  = %00000100        'port A.2 is input
WPUA  = %00000000        'turn off weak pull ups

APFCON = %00000001        'Alternate Pin Function Control Reg (default %00000000)
                          'move CCP to PortA.5 (for PWM output)
OPTION_REG = %10000111    
                        '1 = All weak pull-ups are disabled (except MCLR, if it is enabled)
                        ' 0 = Interrupt on falling edge of RB0/INT pin
                        '  0 = Timer0 clock is internal cycle clock (Fosc/4)
                        '  0 = Increment on low-to-high transition on RA4/T0CKI pin
                        '    0 = Prescaler is assigned to the Timer0 module
                        '    111 = 1:256 Timer0 prescaler rate
                
T1CON = %11000001      'enable timer 1 (bit 0) & source the clock from the CPS module (bit 6 & 7 =11

CPSCON0 = %10001100    'set the CPS module highest frequency availabe (for vcc mode) + timer0 clock sourced from CPS module. (BIT 1)
                        '1 = CPS module is enabled
                        ' 0 = CPS module is in the low range. Internal oscillator voltage references are used.
                        '  00 = unused
                        '    11 = Oscillator is in High Range. Charge/Discharge Current is nominally 18 µA
                        '      0 = Capacitive Sensing Oscillator Status bit (only readable)
                        '      0 = Timer0 clock source is controlled by the core/Timer0 module and is FOSC/4

CPSCON1 = %00000010        '0010 = channel 2, (CPS2)

CM1CON0 = 0  ' COMPARATOR OFF
CM1CON1 = 0  ' COMPARATOR OFF

CPS2_PRESENT    var WORD
CPS2_THRESHOLD  var WORD
CPS2_LAST      var WORD

'      Software variables
'      ==================
Duty    VAR WORD
stepp  var byte


' ----------------[ I/O Definitions ]-----------------------------------
FET VAR PORTA.5  ' PWM output to control the FET switch

'      Software/Hardware initialisation
'      ================================
PAUSE 50                          ' OSC settle delay
Duty = 0
stepp = 5
hpwm 1,255,250                    ' Start with Light full ON
pause 1000
    
ASM
INT_LIST  macro    ; IntSource,        Label,  Type, ResetFlag?
        INT_Handler  TMR0_INT,  _Timer0_Int,  pbp,  yes
    endm
    INT_CREATE              ; Creates the interrupt processor
ENDASM

TMR0 = 0                  'clear  TIMER0
@ INT_ENABLE  TMR0_INT    'enable timer0 interrupts
'***********************************************************************
'------------------------------< Main program >-------------------------
Main:
pause 100  ' not a whole lot going on here
goto main

'*****************************************************************************
Timer0_Int:
@ INT_DISABLE  TMR0_INT  ' stop timer0 interrupts while we're in here
pause 25

CPS2_PRESENT = TMR1                                ' take a snapshot of Timer1's present count.
CPS2_THRESHOLD = CPS2_LAST - ((CPS2_LAST/10)*2)    ' this sets the 'trigger' up for a 20% diversion (finger press)
CPS2_LAST = CPS2_PRESENT                          ' store away the present timer0count for the next time we come into the interrupt routine

if cps2_present < cps2_threshold then
    stepp = stepp +1
    if stepp>6 then stepp=0            ' check for rollover
    lookup stepp, [0,1,16,64,128,255,255],duty  'choose level, 5 levels plus OFF
    if stepp=6 then 
        hpwm 1,0,1000    'off              ' arrive here when brightness is MAX
        pause 100                          '    So blink to let user know.
        hpwm 1,255,1000  'on
        pause 100
        hpwm 1,0,1000    'off
        pause 100
        hpwm 1,255,1000  'on              ' blink to show that you are at the highest level
    endif    
    hpwm 1,duty,250                    ' else set new level                      ' button pressed so increment stepp  
    pause 100
endif

pause 50      
TMR0 = 0                  ' clear TIMER0    
TMR1 = 0                  ' clear TIMER1
@ INT_ENABLE  TMR0_INT    ' re-enable timer0 interrupt
@ INT_RETURN  
end

ASM
  __CONFIG _CONFIG1, _FCMEN_OFF & _FOSC_INTOSC & _WDTE_SWDTEN & _MCLRE_OFF & _CP_OFF & _IESO_OFF & _BOREN_OFF & _PWRTE_OFF
  __CONFIG _CONFIG2, _LVP_OFF
ENDASM