'************************************************************************************************************************
' 0.1 to 40 Hz ELF Recorder
' File name : recorder-1.pbp
' Date : 2011-11
' Author : Serge Lacôte
' Langage : PICBASIC PRO 2.6 ; LONG option enabled
' Assembler : MPASM v5.42
' MCU target : PIC18LF4620
' ADC : Analog Device AD7680 (16 bit)
' RTC : Maxim DS1302
' Serial interface : Maxim MAX3232
' Medium : SD card (2Go) ; the card must be initialized in plain FAT16 (16bit version FAT) WITHOUT PARTITION before using 
' with following parameters : sector size : 512 Bytes, cluster size : 64 sectors i.e. 32 kB.
' Supply voltage : 3.3 V
' File system : FAT16
' Prescaler TIMER0 : none ; stop counter : 37523 - T0CON = % x0001000 
' If Prescaler 1:4 stop counter : 9445 - T0CON = % x0000001 *** If 1:8 stop counter : 4723 - T0CON = %x0000010
' Sample rate : 128 sps  
' This program may be freely used, copied and modified for a private using
'************************************************************************************************************************
'************************************************************************************************************************
DEFINE OSC 20	' The crystal frequency is 20 MHz ; the instruction frequency is 5 MHz
' PIC18LF4620 ports and direction registers
' NOTA. IN SPI mode, the names IN, OUT, CS, etc. refer to the uC (master), not to the slave chip.
SD_CS  						Var PORTC.1
SD_CS_TRIS  				Var TRISC.1   
SCL  						Var PORTC.3
SCL_TRIS  					Var TRISC.3   
SDO  						Var PORTC.5
SDO_TRIS					Var TRISC.5   
SDI  						Var PORTC.4
SDI_TRIS  					Var TRISC.4   
ADC_CS    					Var PORTD.2
ADC_CS_TRIS    				Var TRISD.2   
ADC_SDATA 					Var PORTD.3
ADC_SDATA_TRIS 				Var TRISD.3   
ADC_SCLK  					Var PORTD.4
ADC_SCLK_TRIS 				Var TRISD.4
START_BUT					Var PORTB.0 
START_BUT_TRIS				Var	TRISB.0	  
LED_RED 					Var PORTD.1
LED_RED_TRIS 				Var TRISD.1   
LED_GREEN 					Var PORTD.0
LED_GREEN_TRIS 				Var TRISD.0   
CLOSE_BUTTON 				Var PORTB.2
CLOSE_BUTTON_TRIS 			Var TRISB.2
SETTING_BUT					Var	PORTB.1	
SETTING_BUT_TRIS			Var	TRISB.1 
RTC_IO						Var PORTE.1
RTC_IO_TRIS					Var TRISE.1
RTC_CLK						Var PORTE.0
RTC_CLK_TRIS				Var TRISE.0
RTC_CE  					Var	PORTE.2
RTC_CE_TRIS  				Var	TRISE.2
CUT_OFF_BATT				Var	PORTD.5
CUT_OFF_BATT_TRIS			Var TRISD.5
' Various variables
YEAR						Var	Byte		' BDC coded DS1302 year  (00-99)
MONTH						Var	Byte		' BDC coded DS1302 month (1-12)
DATE						Var	Byte		' BDC coded DS1302 date (1-31) 
HOUR						Var	Byte		' BDC coded DS1302 hour (0-23)
MINUTE						Var	Byte		' BDC coded DS1302 minute (00-59)
SECOND						Var	Byte		' BDC coded DS1302 second (00-59)
DAY							Var Byte		' Non implemented in FAT16
RTC_CTRL					Var	Byte		' ds1302 control
SAMPLE 						Var Word
BIT_COUNTER   				Var Byte  	  
VALUE_TO_SHIFT   			Var Byte    
TYPE_1_CARD_REPLY			Var Byte    	' 8 bits reply
TYPE_2_CARD_REPLY			Var Word    	' 16 bits reply
CARD_ADRESS_HIGH			Var Word    	' Bits 16 to 31
CARD_ADRESS_LOW				Var Word    	' Bits 0 to 15
SAMPLE_CNTR					Var Byte		' Counter
I							Var Word    	' Counter
J 							Var Word    	' Counter
K 							Var Word    	' Counter
L 							Var Word    	' Counter
M							Var Byte		' Counter
N							Var Byte		' Counter
CHOICE						Var	Byte
CARD_REPLY_4BIT     		Var Byte    
BYTES_PER_SECTOR			Var Word   
SECTORS_PER_CLUSTER			Var Byte   
RESERVED_SECTORS    		Var Word   
FAT_EXEMPLARS_NBR    		Var Byte	 	
ROOT_ENTRIES_NBR   			Var Word	
SECTORS_PER_FAT   			Var Word	
DATA_SECTOR_ADRESS_LOW   	Var Word   
DATA_SECTOR_ADRESS_HIGH  	Var Word   
FAT_SECTOR_ADRESS_LOW   	Var Word   
FAT_SECTOR_ADRESS_HIGH   	Var Word   
ROOT_SECTOR_ADRESS_LOW   	Var Word   
ROOT_SECTOR_ADRESS_HIGH   	Var Word   
CLUSTER_CNTR				Var Word    
SECTOR_CNTR					Var Byte    
FILE_LENGTH_HIGH  			Var Word    	' High Word File length
FILE_LENGTH_LOW				Var Word    	' Low Word File length
FAT_HOUR 					Var Word				
FAT_MINUTE 					Var Word		
FAT_SECOND					Var Word		
FAT_YEAR					Var	Word		
FAT_MONTH					Var Word		
FAT_DATE					Var Word		
FAT_HMS						Var Word		' Hours, minutes and second coded on 2 bytes according to FAT16 specifications
FAT_YMD						Var Word		' Year, month and date coded on 2 bytes according to FAT16 specifications
RECORDING_TIME			Var Word		' Recording time in hours.
RECORDING_TIME_CLUST		Var Word		' Recording time in number of clusters.
FILE_NAME					Var Byte[8]
'************************************************************************************************************************
' Various register initialization                
INTCON = %00000000			' Interrupts disabled
INTCON2 = %00000000         ' Pullups on PORTB enabled 
INTCON3 = %00000000			' External interrupts disabled
ADCON1 = %00001111			' I/O for all ports
T0CON = %00001000   		' TIMER0 disabled ; no prescaler
'************************************************************************************************************************
' Direction registers   
START_BUT_TRIS = 1
SETTING_BUT_TRIS = 1		
SD_CS_TRIS = 0	   
SCL_TRIS = 0	   
SDO_TRIS = 0		   
SDI_TRIS = 1 		   
ADC_CS_TRIS = 0   		   
ADC_SDATA_TRIS = 1		   
ADC_SCLK_TRIS = 0		   
LED_RED_TRIS = 0		   
LED_GREEN_TRIS = 0		   
CLOSE_BUTTON_TRIS = 1
RTC_CLK_TRIS = 0
RTC_CE_TRIS = 0
CUT_OFF_BATT_TRIS = 0
'************************************************************************************************************************
Pause 1000
CUT_OFF_BATT = 0
' Waiting loop for settings 
Pause 1000
If SETTING_BUT == 0 Then
	Gosub SETTINGS
EndIf
' Start waiting loop 
M = 0
While 1 ' Waiting loop
	button START_BUT, 0, 0, 0, M, 1, MAIN
Wend 	   
'************************************************ MAIN ******************************************************************
MAIN :
Pause 1000
LED_RED = 0
LED_GREEN = 0
Pause 1000 
GoSub SD_INIT 
GoSub READ_BOOT_SECTOR        
' FAT sector        
I = RESERVED_SECTORS
GoSub CARD_ADDRESS_CALCULATION
FAT_SECTOR_ADRESS_LOW = CARD_ADRESS_LOW 
FAT_SECTOR_ADRESS_HIGH = CARD_ADRESS_HIGH
' ROOT sector        
I = I + SECTORS_PER_FAT * FAT_EXEMPLARS_NBR
GoSub CARD_ADDRESS_CALCULATION
ROOT_SECTOR_ADRESS_LOW = CARD_ADRESS_LOW
ROOT_SECTOR_ADRESS_HIGH = CARD_ADRESS_HIGH
' Data sector        
I = I + (ROOT_ENTRIES_NBR / 512) * 32
GoSub CARD_ADDRESS_CALCULATION
DATA_SECTOR_ADRESS_LOW = CARD_ADRESS_LOW
DATA_SECTOR_ADRESS_HIGH = CARD_ADRESS_HIGH             
CLUSTER_CNTR = 0    
SECTOR_CNTR = 0 
CARD_ADRESS_LOW = DATA_SECTOR_ADRESS_LOW
CARD_ADRESS_HIGH = DATA_SECTOR_ADRESS_HIGH       
FILE_LENGTH_LOW = 0
FILE_LENGTH_HIGH = 0      
LED_GREEN = 1  
SAMPLE_CNTR = 0
READ 0, Word RECORDING_TIME
RECORDING_TIME_CLUST = RECORDING_TIME */ 7200
'Serout2 PORTC.6, 84, ["recording cluster numbers = ", DEC RECORDING_TIME_CLUST, 13]
GoSub READ_TIME		' Creation date (beginning of the recording)	
GoSub WRITE_INIT
While (CLOSE_BUTTON == 1) && (CLUSTER_CNTR < RECORDING_TIME_CLUST) 
	For SAMPLE_CNTR = 0 to 254
		GoSub DIGITIZE   	      
   		VALUE_TO_SHIFT = SAMPLE.byte0
    	GoSub FAST_SHIFTOUT  ' Writing on the card
    	VALUE_TO_SHIFT = SAMPLE.byte1
    	GoSub FAST_SHIFTOUT  ' Writing on the card
    	TMR0L = 0
    	TMR0H = 0
		T0CON.7 = 1		' TMR0 enabled ; counting trigged	              
    	While TMR0L + 256 * TMR0H < 37523
    	Wend 
    	T0CON.7 = 0 	' TMR0 disabled
		TMR0L = 0
    	TMR0H = 0
	Next SAMPLE_CNTR
	' 256th sample (#255), write end and write init for the new sector (if it is)
	GoSub DIGITIZE   	      
   	VALUE_TO_SHIFT = SAMPLE.byte0
    GoSub FAST_SHIFTOUT  ' Writing on the card
    VALUE_TO_SHIFT = SAMPLE.byte1
    GoSub FAST_SHIFTOUT  ' Writing on the card
    TMR0L = 0
    TMR0H = 0
	T0CON.7 = 1		' TMR0 enabled ; counting trigged
	GoSub WRITE_END
	SECTOR_CNTR = SECTOR_CNTR + 1            
    If SECTOR_CNTR = SECTORS_PER_CLUSTER Then
    	CLUSTER_CNTR = CLUSTER_CNTR + 1
    	SECTOR_CNTR = 0                     
	EndIf	
	CARD_ADRESS_LOW = CARD_ADRESS_LOW + $0200            
    If CARD_ADRESS_LOW = $0000 Then
    	CARD_ADRESS_HIGH = CARD_ADRESS_HIGH + 1
    EndIf
   	FILE_LENGTH_LOW = FILE_LENGTH_LOW + 512   
    If FILE_LENGTH_LOW = 0 Then
    	FILE_LENGTH_HIGH = FILE_LENGTH_HIGH + 1
    EndIf
	If (CLOSE_BUTTON == 1) && (CLUSTER_CNTR < RECORDING_TIME_CLUST) Then
		GoSub WRITE_INIT
	EndIf
	While TMR0L + 256 * TMR0H < 37523
    Wend 
    T0CON.7 = 0 	' TMR0 disabled
	TMR0L = 0
    TMR0H = 0 	
Wend
GoSub CLOSE_FILE   
FINISHED :
LED_GREEN = 0
Pause 5000
CUT_OFF_BATT = 1
End   
'************************************************************************************************************************
'				                    	 SUBROUTINES
'************************************************************************************************************************
'************************************************************************************************************************
SETTINGS :
Pause 100
Serout2 PORTC.6, 84, [0, 0, 0, 0, 0, "Setting procedure", 13]
Serout2 PORTC.6, 84, 10, ["A : Time setting", 13, "B : Display time", 13, "C : Recording time", 13, "D : Close", 13, "Choice : ", 13]
Serout2 PORTC.6, 84, [" !!! Send the choice as a STRING ", 13]
Serin2	PORTC.7, 84, [CHOICE]
Serout2 PORTC.6, 84, [13]
Select Case CHOICE
Case "A"
	Serout2 PORTC.6, 84, ["Set time procedure", 13]
	Serout2 PORTC.6, 84, [" !!! Write the answers in ordinary DEC, but send them as HEX !!! ", 13]
	Serout2 PORTC.6, 84, [" !!! Time is UTC, not local time !!! ", 13]
	Serout2 PORTC.6, 84, 10, ["Day (1-7) : "]
	Serin2	PORTC.7, 84, [DAY]
	Serout2 PORTC.6, 84, 10, [13, "Year (00-99) : "]
	Serin2	PORTC.7, 84, [YEAR]
	Serout2 PORTC.6, 84, 10,[13, "Month (1-12) : "]
	Serin2	PORTC.7, 84, [MONTH]
	Serout2 PORTC.6, 84, 10,[13, "Date (1-31) : "]
	Serin2	PORTC.7, 84, [DATE]
	Serout2 PORTC.6, 84, 10,[13, "Hour (0-23) : "]
	Serin2	PORTC.7, 84, [HOUR]
	Serout2 PORTC.6, 84, 10,[13, "Minutes (00-59) : "]
	Serin2	PORTC.7, 84, [MINUTE]
	Serout2 PORTC.6, 84, 10,[13, "Seconds (00-59) : "]
	Serin2	PORTC.7, 84, [SECOND]
	Serout2 PORTC.6, 84, [13, 10]
	High RTC_CE		' Transfer enable
	RTC_IO_TRIS = 0
	Shiftout RTC_IO, RTC_CLK, 0, [$8E, 0]		' DS1302 write bit enable
	Low RTC_CE		' Transfer disable
	High RTC_CE 	' Transfer enable
	Shiftout RTC_IO, RTC_CLK, 0, [$BE, SECOND, MINUTE, HOUR, DATE, MONTH, DAY, YEAR, 0]
	Low RTC_CE
	GoTo SETTINGS
Case "B"
	Serout2 PORTC.6, 84, ["Format : #day (1=Sunday) * year-month-date ; hour:minute:second", 13]
	Gosub READ_TIME
	Serout2 PORTC.6, 84, [HEX DAY, " * ", HEX YEAR, "-", HEX MONTH, "-", HEX DATE, "  ;  ", HEX HOUR, ":", HEX MINUTE, ":", HEX SECOND, 13] ' Display DS1302 time
	GoTo SETTINGS
Case "C"
	Serout2 PORTC.6, 84, ["Recording time in hours (integer < 256)", 13]
	Serout2 PORTC.6, 84, ["The real recording time may be slightly higher (up to 128 seconds)than the entered time", 13]
	Serout2 PORTC.6, 84, ["Write and send the answer in DEC", 13]
	Serout2	PORTC.6, 84, 10, ["RECORDING_TIME : "]
	Serin2	PORTC.7, 84, [RECORDING_TIME]
	Write 0, Word RECORDING_TIME
	GoTo SETTINGS
Case "D"
	Serout2	PORTC.6, 84, 10, [13, "Settings done ; the system will shutdown in 10 seconds."]
	Pause 5000
	Goto FINISHED
End Select
Return
'************************************************************************************************************************
'************************************************************************************************************************
READ_TIME :
High RTC_CE		' Transfer enable
RTC_IO_TRIS = 0
Shiftout RTC_IO, RTC_CLK, 0, [$BF]		' Read all 8 registers in burst mode
RTC_IO_TRIS = 1
Shiftin RTC_IO, RTC_CLK, 1, [SECOND, MINUTE, HOUR, DATE, MONTH, DAY, YEAR, RTC_CTRL]
Low RTC_CE		' Transfer disable
Return
'************************************************************************************************************************
'************************************************************************************************************************
FILE_DATING :
' Set file time and date to DS1302 time
FAT_HOUR = HOUR.0 + 2 * HOUR.1 + 4 * HOUR.2 + 8 * HOUR.3 + 10 * (HOUR.4 + 2 * HOUR.5 + 4 * HOUR.6 + 8 * HOUR.7)
FAT_MINUTE = MINUTE.0 + 2 * MINUTE.1 + 4 * MINUTE.2 + 8 * MINUTE.3 + 10 * (MINUTE.4 + 2 * MINUTE.5 + 4 * MINUTE.6 + 8 * MINUTE.7)
FAT_SECOND = SECOND.1 + 2 * SECOND.2 + 4 * SECOND.3 + 5 * (SECOND.4 + 2 * SECOND.5 + 4 * SECOND.6 + 8 * SECOND.7)
FAT_YEAR = YEAR.0 + 2 * YEAR.1 + 4 * YEAR.2 + 8 * YEAR.3 + 10 * (YEAR.4 + 2 * YEAR.5 + 4 * YEAR.6 + 8 * YEAR.7) + 20
FAT_MONTH = MONTH.0 + 2 * MONTH.1 + 4 * MONTH.2 + 8 * MONTH.3 + 10 * (MONTH.4 + 2 * MONTH.5 + 4 * MONTH.6 + 8 * MONTH.7)
FAT_DATE = DATE.0 + 2 * DATE.1 + 4 * DATE.2 + 8 * DATE.3 + 10 * (DATE.4 + 2 * DATE.5 + 4 * DATE.6 + 8 * DATE.7)	
Return
'************************************************************************************************************************
'************************************************************************************************************************
SD_INIT:        
' Sending of 80 (10 x 8) empty clock cycles 
SD_CS = 1	
For I = 1 TO 10	
	SHIFTOUT SDO, SCL, 5, [$FF]  ' data out highest bit first, Clock idles high
Next I
SD_CS = 0
Pause 1	
' New delay of 16 clocks	
SHIFTOUT SDO, SCL, 5, [$FF]
SHIFTOUT SDO, SCL, 5, [$FF]  
' CMD0 sending
SHIFTOUT SDO, SCL, 5, [$40,$00,$00,$00,$00,$95] 
SHIFTIN SDI, SCL, 6, [TYPE_1_CARD_REPLY]         
I = 0
While TYPE_1_CARD_REPLY <> 1
	SHIFTIN SDI, SCL, 6, [TYPE_1_CARD_REPLY]  
   	I = I + 1
   	If I > 5000 Then FATAL_ERROR 
Wend
SD_CS=1
Pause 1
SD_CS=0
'Serout2 PORTC.6, 84, ["Reset answer = ", IBIN8 TYPE_1_CARD_REPLY, 10, 13]
'Serout2 PORTC.6, 84, ["SD Init type1 card reply I = ", DEC I, 10, 13]
' CMD1 Card Initialization
I = 0
TYPE_1_CARD_REPLY = 1
While TYPE_1_CARD_REPLY <> 0
	SD_CS=1
	SHIFTOUT SDO,SCL,5,[$FF]
	SHIFTIN SDI,SCL,6,[TYPE_1_CARD_REPLY]
	SD_CS=0
	Pause 1
	SHIFTOUT SDO, SCL, 5, [$41, $00, $00, $00, $00, $FF, $FF] 'CMD1 ; CRC7 not required
	SHIFTIN SDI,SCL,6,[TYPE_1_CARD_REPLY]
   	I = I + 1
   	If I > 5000 Then FATAL_ERROR
Wend
'Serout2 PORTC.6, 84, ["Now card in initialised ; I = ", DEC I, 10, 13]
Return
'************************************************************************************************************************
'************************************************************************************************************************
READ_BOOT_SECTOR:	' Read Boot sector written on the card during the FAT16 formatage
SD_CS = 1	' 
VALUE_TO_SHIFT = $FF
GoSub FAST_SHIFTOUT
GoSub FAST_SHIFTIN
TYPE_1_CARD_REPLY = VALUE_TO_SHIFT
SD_CS=0
VALUE_TO_SHIFT = $51
GoSub FAST_SHIFTOUT
VALUE_TO_SHIFT = $00
GoSub FAST_SHIFTOUT
VALUE_TO_SHIFT = $00
GoSub FAST_SHIFTOUT
VALUE_TO_SHIFT = $00
GoSub FAST_SHIFTOUT
VALUE_TO_SHIFT = $00
GoSub FAST_SHIFTOUT
VALUE_TO_SHIFT = $FF
GoSub FAST_SHIFTOUT
GoSub FAST_SHIFTIN
TYPE_1_CARD_REPLY = VALUE_TO_SHIFT
I = 0
While TYPE_1_CARD_REPLY<> 0
	GoSub FAST_SHIFTIN
   	TYPE_1_CARD_REPLY = VALUE_TO_SHIFT
   	I = I + 1
   	If I > 5000 Then FATAL_ERROR
Wend
' Reading of the start of block token %11111110 preceding data
GoSub FAST_SHIFTIN
TYPE_1_CARD_REPLY = VALUE_TO_SHIFT
I = 0
While TYPE_1_CARD_REPLY<> %11111110          
	GoSub FAST_SHIFTIN
	TYPE_1_CARD_REPLY = VALUE_TO_SHIFT
   	I = I + 1
   	If I > 5000 Then FATAL_ERROR
Wend
' Useful data recuperation from the BOOT sector
For N = 1 to 12										' We skip from $0000 to $000A (11 adresses)
	GoSub FAST_SHIFTIN
    Next N
    BYTES_PER_SECTOR.Byte0 = VALUE_TO_SHIFT					
    GoSub FAST_SHIFTIN
    BYTES_PER_SECTOR.Byte1 = VALUE_TO_SHIFT
    GoSub FAST_SHIFTIN
    SECTORS_PER_CLUSTER = VALUE_TO_SHIFT				
    GoSub FAST_SHIFTIN
    RESERVED_SECTORS.Byte0 = VALUE_TO_SHIFT			
    GoSub FAST_SHIFTIN
    RESERVED_SECTORS.Byte1 = VALUE_TO_SHIFT
    GoSub FAST_SHIFTIN
    FAT_EXEMPLARS_NBR = VALUE_TO_SHIFT					
    GoSub FAST_SHIFTIN
    ROOT_ENTRIES_NBR.Byte0 = VALUE_TO_SHIFT			' Adress $0011
    GoSub FAST_SHIFTIN
    ROOT_ENTRIES_NBR.Byte1 = VALUE_TO_SHIFT
    For N = 1 to 4									' We skip from  $0013 to $0015
       	GoSub FAST_SHIFTIN
Next N
SECTORS_PER_FAT.Byte0 = VALUE_TO_SHIFT			
GoSub FAST_SHIFTIN
SECTORS_PER_FAT.Byte1 = VALUE_TO_SHIFT
For I = 1 TO 488
 	GoSub FAST_SHIFTIN
Next I
' CRC
GoSub FAST_SHIFTIN
TYPE_1_CARD_REPLY = VALUE_TO_SHIFT
GoSub FAST_SHIFTIN
TYPE_1_CARD_REPLY = VALUE_TO_SHIFT
' CMD13
SD_CS=1
VALUE_TO_SHIFT = $FF
GoSub FAST_SHIFTOUT
GoSub FAST_SHIFTIN
TYPE_1_CARD_REPLY = VALUE_TO_SHIFT
SD_CS=0
VALUE_TO_SHIFT = $4D
GoSub FAST_SHIFTOUT
VALUE_TO_SHIFT = $00
GoSub FAST_SHIFTOUT
VALUE_TO_SHIFT = $00
GoSub FAST_SHIFTOUT
VALUE_TO_SHIFT = $00
GoSub FAST_SHIFTOUT
VALUE_TO_SHIFT = $00
GoSub FAST_SHIFTOUT
VALUE_TO_SHIFT = $0D
GoSub FAST_SHIFTOUT
GoSub FAST_SHIFTIN
TYPE_2_CARD_REPLY.BYTE1 = VALUE_TO_SHIFT
GoSub FAST_SHIFTIN
TYPE_2_CARD_REPLY.BYTE0 = VALUE_TO_SHIFT
J=0
While TYPE_2_CARD_REPLY.BYTE0 <> 0
	GoSub FAST_SHIFTIN
	TYPE_2_CARD_REPLY.BYTE1 = VALUE_TO_SHIFT
	GoSub FAST_SHIFTIN
	TYPE_2_CARD_REPLY.BYTE0 = VALUE_TO_SHIFT
	J = J + 1
	If J > 5000 Then FATAL_ERROR
Wend
Return     
'************************************************************************************************************************
'************************************************************************************************************************
CARD_ADDRESS_CALCULATION:
CARD_ADRESS_LOW = 0
CARD_ADRESS_HIGH = 0
For J = 1 TO I 
	CARD_ADRESS_LOW = CARD_ADRESS_LOW + $0200
    If CARD_ADRESS_LOW = $0000 Then
    	CARD_ADRESS_HIGH = CARD_ADRESS_HIGH + 1
    EndIf
Next J
Return
'************************************************************************************************************************
'************************************************************************************************************************
TIME_PLATEAU:
Asm
	NOP	
	NOP      
EndAsm
Return
'************************************************************************************************************************
' The 2 following subroutines are dedicated to the SD card ports 
' The assembler used is the Microchip MPASM v5.42
'************************************************************************************************************************
FAST_SHIFTIN:
Asm
	BSF    TRISC, 4				; SDI port in    
	BCF    TRISC, 3				; Clock port SLC out    
	BCF    PORTC, 3				; Clock port SLC low    
	MOVLW  7					; Load 7 in the work register W
	MOVWF  _BIT_COUNTER			; Save the W register value in _BIT_COUNTER
	CLRF   _VALUE_TO_SHIFT		; Clear _VALUE_TO_SHIFT       
BEGIN
	BTFSC  PORTC, 4				; If SDI low, then skip following instruction    
	INCF   _VALUE_TO_SHIFT, 1	; Increment _VALUE_TO_SHIFT     
	BCF    STATUS, C			; Clear Carry bit in STATUS register
	RLCF   _VALUE_TO_SHIFT, 1   ; Rotate left _VALUE_TO_SHIFT using Carry bit
	BSF    PORTC, 3				; SLC high    
	NOP                			; 1 instruction delay
	BCF    PORTC, 3				; SLC low    
	DECFSZ _BIT_COUNTER, 1		; Decrement _BIT_COUNTER    
	GoTo   BEGIN				;       
	BTFSC  PORTC, 4				; If SDI low, then jump to BSF   
	INCF   _VALUE_TO_SHIFT, 1   ; Increment _VALUE_TO_SHIFT  
	BSF    PORTC, 3				; SLC high    
	NOP   						; 1 instruction delay             
	BCF    PORTC, 3    			; SLC low
	NOP							; 1 instruction delay
EndAsm
Return             
'************************************************************************************************************************
'************************************************************************************************************************
FAST_SHIFTOUT:
Asm
	BCF    TRISC, 5				; SDO port out    
	BCF    TRISC, 3				; SCL port out    
	BCF    PORTC, 3				; SCL low	    
	MOVLW  8					; Load 8 in the work register W           
	MOVWF  _BIT_COUNTER			; Save the W register in _BIT_COUNTER
LABEL_1
	BCF    STATUS, C			; Clear Carry bit in STATUS register   
	RLCF   _VALUE_TO_SHIFT, 1	; Rotate left _VALUE_TO_SHIFT using Carry bit     
	BTFSS  STATUS, C			; If Carry bit in STATUS register high, then skip following instruction     
	GoTo   LABEL_2					         
	BSF    PORTC, 5				; SDO high    
	GoTo   LABEL_3    
LABEL_2
	BCF    PORTC, 5				; SDO low     
LABEL_3
	BSF    PORTC, 3				; SCL high    
	NOP							; 1 instruction delay                
	BCF    PORTC, 3				; SCL low    
	DECFSZ _BIT_COUNTER, 1		; Decrement _BIT_COUNTER    
	GoTo   LABEL_1       
	NOP							; 1 instruction delay
EndAsm
Return             
'************************************************************************************************************************
'************************************************************************************************************************
WRITE_INIT:
SD_CS=1
VALUE_TO_SHIFT = $FF
GoSub FAST_SHIFTOUT
GoSub FAST_SHIFTIN
TYPE_1_CARD_REPLY = VALUE_TO_SHIFT
'CMD24 sending
SD_CS=0
VALUE_TO_SHIFT = $58
GoSub FAST_SHIFTOUT
VALUE_TO_SHIFT = CARD_ADRESS_HIGH.BYTE1
GoSub FAST_SHIFTOUT
VALUE_TO_SHIFT = CARD_ADRESS_HIGH.BYTE0
GoSub FAST_SHIFTOUT
VALUE_TO_SHIFT = CARD_ADRESS_LOW.BYTE1
GoSub FAST_SHIFTOUT
VALUE_TO_SHIFT = CARD_ADRESS_LOW.BYTE0
GoSub FAST_SHIFTOUT
VALUE_TO_SHIFT = $FF	' CRC7 no required
GoSub FAST_SHIFTOUT
GoSub FAST_SHIFTIN
TYPE_1_CARD_REPLY = VALUE_TO_SHIFT
J = 0
'Card reply reception
While TYPE_1_CARD_REPLY <> 0
	GoSub FAST_SHIFTIN
	TYPE_1_CARD_REPLY = VALUE_TO_SHIFT
	J = J + 1
	If J > 5000 Then FATAL_ERROR
Wend
'Serout2 PORTC.6, 84, ["write init t1cr J = ", DEC J, 10, 13]
VALUE_TO_SHIFT = $FE	' Starting block
GoSub FAST_SHIFTOUT
Return
'************************************************************************************************************************
'************************************************************************************************************************
FATAL_ERROR :
LED_GREEN = 0
LED_RED = 1
Pause 3000
GoTo FINISHED
Return
'************************************************************************************************************************
'************************************************************************************************************************
WRITE_END:
' Answer to write command analysis
VALUE_TO_SHIFT = $FF
GoSub FAST_SHIFTOUT
VALUE_TO_SHIFT = $FF
GoSub FAST_SHIFTOUT
GoSub FAST_SHIFTIN
TYPE_1_CARD_REPLY = VALUE_TO_SHIFT
CARD_REPLY_4BIT = %00000000
CARD_REPLY_4BIT = TYPE_1_CARD_REPLY & $0F
If CARD_REPLY_4BIT <> %00000101 Then FATAL_ERROR
' Busy bit ; the answer time must be long (J > 1000) with some cards
GoSub FAST_SHIFTIN
TYPE_1_CARD_REPLY = VALUE_TO_SHIFT
J=0
While TYPE_1_CARD_REPLY = 0
	GoSub FAST_SHIFTIN
    TYPE_1_CARD_REPLY = VALUE_TO_SHIFT
  	J = J + 1
   	If J > 10000 Then FATAL_ERROR
Wend
'Serout2 PORTC.6, 84, ["write end - bit busy t1cr J = ", DEC J, 10, 13]
' CMD13 sending
SD_CS=1
VALUE_TO_SHIFT = $FF
GoSub FAST_SHIFTOUT
GoSub FAST_SHIFTIN
TYPE_1_CARD_REPLY = VALUE_TO_SHIFT
SD_CS=0
VALUE_TO_SHIFT = $4D
GoSub FAST_SHIFTOUT
VALUE_TO_SHIFT = $00
GoSub FAST_SHIFTOUT
VALUE_TO_SHIFT = $00
GoSub FAST_SHIFTOUT
VALUE_TO_SHIFT = $00
GoSub FAST_SHIFTOUT
VALUE_TO_SHIFT = $00
GoSub FAST_SHIFTOUT
VALUE_TO_SHIFT = $FF	' CRC7 non required
GoSub FAST_SHIFTOUT
GoSub FAST_SHIFTIN
TYPE_2_CARD_REPLY.BYTE1 = VALUE_TO_SHIFT
GoSub FAST_SHIFTIN
TYPE_2_CARD_REPLY.BYTE0 = VALUE_TO_SHIFT
J=0
While TYPE_2_CARD_REPLY.BYTE0 <> 0
	GoSub FAST_SHIFTIN
	TYPE_2_CARD_REPLY.BYTE1 = VALUE_TO_SHIFT
	GoSub FAST_SHIFTIN
	TYPE_2_CARD_REPLY.BYTE0 = VALUE_TO_SHIFT
	J = J + 1
	If J > 5000 Then FATAL_ERROR
Wend
'Serout2 PORTC.6, 84, ["write end type 2 cr J = ", DEC J, 10, 13]
Return
'************************************************************************************************************************
'************************************************************************************************************************
CLOSE_FILE:
' ROOT SECTOR
CARD_ADRESS_LOW = ROOT_SECTOR_ADRESS_LOW                  
CARD_ADRESS_HIGH = ROOT_SECTOR_ADRESS_HIGH                  
GoSub WRITE_INIT
' File name and attributes
GoSub FILE_NAMING	' Name file recording on the card (made from the beginning date and hour)
For N = 0 TO 2
	VALUE_TO_SHIFT = 0
    GoSub FAST_SHIFTOUT
Next N
' Creation hour and date ; here time and hour are the beginning ones
VALUE_TO_SHIFT = FAT_HMS.Byte0
GoSub FAST_SHIFTOUT
VALUE_TO_SHIFT = FAT_HMS.Byte1
GoSub FAST_SHIFTOUT
VALUE_TO_SHIFT = FAT_YMD.Byte0
GoSub FAST_SHIFTOUT
VALUE_TO_SHIFT = FAT_YMD.Byte1
GoSub FAST_SHIFTOUT
For N = 18 TO 21
	VALUE_TO_SHIFT = 0
	GoSub FAST_SHIFTOUT
Next N  
' Cloture hour and date (written in "last modification" entry) 
GoSub READ_TIME
GoSub FILE_DATING	' Here time and hour are end of recording ones
FAT_HMS = FAT_SECOND | (FAT_MINUTE << 5) | (FAT_HOUR << 11)		'FAT16 format for Date and Time
FAT_YMD = FAT_DATE | (FAT_MONTH << 5) | (FAT_YEAR << 9)	
VALUE_TO_SHIFT = FAT_HMS.Byte0
GoSub FAST_SHIFTOUT
VALUE_TO_SHIFT = FAT_HMS.Byte1
GoSub FAST_SHIFTOUT
VALUE_TO_SHIFT = FAT_YMD.Byte0
GoSub FAST_SHIFTOUT
VALUE_TO_SHIFT = FAT_YMD.Byte1
GoSub FAST_SHIFTOUT
' First cluster number
VALUE_TO_SHIFT = $2
GoSub FAST_SHIFTOUT
VALUE_to_SHIFT = 0
GoSub FAST_SHIFTOUT       
' File size      	
VALUE_TO_SHIFT = FILE_LENGTH_LOW.BYTE0          
GoSub FAST_SHIFTOUT                     
VALUE_TO_SHIFT = FILE_LENGTH_LOW.BYTE1
GoSub FAST_SHIFTOUT
VALUE_TO_SHIFT = FILE_LENGTH_HIGH.BYTE0
GoSub FAST_SHIFTOUT
VALUE_TO_SHIFT = FILE_LENGTH_HIGH.BYTE1
GoSub FAST_SHIFTOUT
For K = 32 TO 511
	VALUE_TO_SHIFT = 0
    GoSub FAST_SHIFTOUT
Next K
GoSub WRITE_END
' FAT1 Sector
If SECTOR_CNTR <> 0 Then            
	CLUSTER_CNTR = CLUSTER_CNTR + 3              
Else
    CLUSTER_CNTR = CLUSTER_CNTR + 2              
EndIf
L = $0003                						' First cluster
CARD_ADRESS_LOW = FAT_SECTOR_ADRESS_LOW     	
CARD_ADRESS_HIGH = FAT_SECTOR_ADRESS_HIGH
GoSub WRITE_INIT
VALUE_TO_SHIFT = $F8
GoSub FAST_SHIFTOUT
VALUE_TO_SHIFT = $FF
For N = 1 TO 3              
	GoSub FAST_SHIFTOUT
Next N          
K = 4                     
While L < CLUSTER_CNTR
	VALUE_TO_SHIFT = L.BYTE0             
    GoSub FAST_SHIFTOUT                    
    VALUE_TO_SHIFT = L.BYTE1
    GoSub FAST_SHIFTOUT
    K = K + 2            
    L = L + 1            
    If K = 512 Then
    	GoSub WRITE_END
       	K = 0
       	CARD_ADRESS_LOW = CARD_ADRESS_LOW + $0200
       	If CARD_ADRESS_LOW = $0000 Then           
       		CARD_ADRESS_HIGH = CARD_ADRESS_HIGH + 1
       	EndIf
       	GoSub WRITE_INIT                
	EndIf
Wend
VALUE_TO_SHIFT = $FF                      ' End of file
GoSub FAST_SHIFTOUT
VALUE_TO_SHIFT = $FF
GoSub FAST_SHIFTOUT
K = K + 2
While K < 512             
	VALUE_TO_SHIFT = $00
    GoSub FAST_SHIFTOUT
    K = K + 1
Wend
GoSub WRITE_END
Return
'************************************************************************************************************************
'************************************************************************************************************************
DIGITIZE :
ADC_CS = 1
ADC_SCLK = 1
SAMPLE = 0   
ADC_CS = 0 ' Sampling enabled
For N = 1 TO 4  	' Send the 4 leading zeros
  	ADC_SCLK = 0	' Setting of the ADC clock crenel function
   	GoSub TIME_PLATEAU
   	ADC_SCLK = 1
   	GoSub TIME_PLATEAU
Next N
For N = 1 TO 15  ' Sampling of the 15 first bits
   	ADC_SCLK = 0
   	If ADC_SDATA = 1 Then		' Progressive setting of the word type variable SAMPLE
  		SAMPLE = SAMPLE + 1
   	EndIf
   	SAMPLE = SAMPLE << 1
   	GoSub TIME_PLATEAU
   	ADC_SCLK = 1
    GoSub TIME_PLATEAU
Next N
    ADC_SCLK = 0
    If ADC_SDATA = 1 Then  ' Sampling of the 16th bit
      	SAMPLE = SAMPLE + 1
    EndIf
    GoSub TIME_PLATEAU
    ADC_SCLK = 1
	GoSub TIME_PLATEAU
    For N = 1 TO 4  ' Send the 4 trailing zeros
    ADC_SCLK = 0
   	GoSub TIME_PLATEAU
    ADC_SCLK = 1
    GoSub TIME_PLATEAU
Next N
ADC_CS = 1 ' Sampling disabled
Return
'************************************************************************************************************************
'************************************************************************************************************************
FILE_NAMING :	' File name format : MMDDHHMM.DAT
GoSub FILE_DATING
' Bytes sent must be ASCII codes of characters constituting the file name
ArrayWrite FILE_NAME, [DEC FAT_MONTH / 10, DEC FAT_MONTH // 10, DEC FAT_DATE / 10, DEC FAT_DATE // 10, DEC FAT_HOUR / 10, DEC FAT_HOUR // 10, DEC FAT_MINUTE / 10, DEC FAT_MINUTE // 10]
For N = 0 to 7
	ArrayRead FILE_NAME, [Skip N, VALUE_TO_SHIFT]
	GoSub FAST_SHIFTOUT
Next N
VALUE_TO_SHIFT = "D"
GoSub FAST_SHIFTOUT
VALUE_TO_SHIFT = "A"
GoSub FAST_SHIFTOUT
VALUE_TO_SHIFT = "T"
GoSub FAST_SHIFTOUT
Return
'************************************************************************************************************************