' Solar charger
' Olivier de Broqueville. Version 3.3 Feb.2003
' Written and compiled using PROTON+ version 2.00
'
' Use Watchdog, Low power detection and internal OSC with NO clock out
'
' Use of ADIN

		Device = 12f675
        REMARKS ON
		
		CONFIG WDT_ON ,INTRC_OSC_NOCLKOUT,PWRTE_ON, BODEN_ON,MCLRE_OFF
	
		DECLARE WATCHDOG ON
		XTAL = 4
        
'-------[DEFINE PIN SYMBOLS]---------------------------------------------
		Symbol Panneau = GPIO.5		'Trigger for the MOSFET controling the Solar Pannel
		Symbol Charge  = GPIO.4		'Trigger for the MOSFET controling the 'Load'
		Symbol Test    = GPIO.3		'Test pin: If enabled, enter adjustement procedure
        
'-------[ASSIGN VARIABLEs]-----------------------------------------------     
        Dim AD_RESULT as ADRESL.WORD	' Convert the ADRESL register into a WORD variable 
		DIM Surcharge as WORD			' Overload value at which the solar pannel is desactivated
		DIM Decharge  as WORD			' LowBat value at which the 'load' is desactivated
		DIM Tension   as WORD			' Actual voltage level we monitor
		DIM FL_BAS    as BYTE			' Flag used to introduce an hysteresis in 'load' switching
		
'-------[ START SERIOUS THINGS...]---------------------------------------
        Delayms 500						' Wait for the PICmicro to stabilise
    		
'-------[INITIALISATION OF GPIO,AD CONVERTERS, ETC.]----------------------
Initialisation:
		FL_BAS=0
        
		TRISIO = %11111111				' All pins set for input
		ANSEL=%00110111					' Set AN0-AN1-AN2 as analogue input / AN3 as digital input and ADC"s clock for FRC
		ADCON0=%10000000				' Set Right justification of ADC result and VREF to VDD 

'-------[MAIN PROGRAM. LOOP FOREVER]---------------------------------------
Principal:
		While 1 = 1						' Create an infinite loop
 		
Acquisition:
        	Surcharge=ADIN 0			' Perform ADC conversion of Overload reference
        	Surcharge = AD_RESULT
			
			Decharge=ADIN 1			' Perform ADC conversion of Lowbatt reference
        	Decharge = AD_RESULT
			
			Tension=ADIN 2			' Perform ADC conversion of monitored voltage
        	Tension = AD_RESULT
			
			If TEST=0 THEN
' Are we in normal condition (TEST not activated)
' If YES, then control the Panel and the load with delays, histeresis
			
			   If Tension > Surcharge THEN   ' Are we in overload condition (+- 14 volts)?
			   	  LOW Panneau		   		  ' Yes: Disconnect solar pannel
			   ELSE
				  HIGH Panneau			  ' No: Connect solar pannel
			   ENDIF
			
			   IF FL_BAS=0 then	   		  ' Was the load already connected? (Hysteresis)
			   	  IF Tension > Decharge THEN ' Yes. Then is the battery voltage above minimum?
			   	  	 HIGH Charge		 	  ' Yes: Connect the 'Load'
			   	  ELSE
			   	  	  LOW CHARGE			  ' No: Disconnect the 'Load'
				  	  FL_BAS=1				  ' And prepare for hysteresis
			   	  ENDIF
			   ELSE
			   	   IF Tension> (Decharge+40) THEN	'"Histeresis" active: are we above the limit (1volt)
			   	   	  HIGH Charge			 ' YES: Let's connect the 'Load'
				  	  FL_BAS=0				 ' and clear the flag
			   	   ELSE
			   	   	  LOW Charge			 ' NO: Stay disconnected
			   	   ENDIF
			   ENDIF
			
			   IF Tension > (Surcharge+40) THEN 
			   	  LOW Charge	' By the way, are we not overloading the 'Load'?(Above Overload limit + 1volt)
			   ENDIF   		   	 					 	 		
			
         	   SNOOZE 6					' Wait for half a second

' If NO then skip all delays to facilitate adjustements	
			ELSE
		   	   If Tension > Surcharge THEN   ' Are we in overload condition (+- 14 volts)?
			   	  LOW Panneau		   		  ' Yes: Disconnect solar pannel
		   	   ELSE
				  HIGH Panneau			  ' No: Connect solar pannel
		       ENDIF
			
		       IF Tension > Decharge THEN ' Is the battery voltage above minimum?
			      HIGH Charge		 	  ' Yes: Connect the 'Load'
		       ELSE
			      LOW CHARGE			  ' No: Disconnect the 'Load'
		       ENDIF	
			
		       IF Tension > (Surcharge+40) THEN 
		   	      LOW Charge	' By the way, are we not overloading the 'Load'?(Above Overload limit + 1volt)
		       ENDIF   		   	 					 	 		'
		    ENDIF
		
        Wend							' Do another control cycle
'--------------------------------------------------------------------------
      END