;______________________________________
;         MODULE DS3231
; Matériel : 	ATtiny 45/85 4MHz mini 5V
; 				
; (c) sammy76.free.fr
;	V1.0 2016/06/01 Juin 2016
;______________________________________
; V1.0 
;        ATtiny45 - 8MHz interne
;             +-\/-+
; 	     PB5 1|-  -|8  Vcc
;	 SCL PB3 2|-  -|7  PB2
;    SDA PB4 3|-  -|6  PB1
;		 GND 4|-  -|5  PB0 
;             +----+
;ATtiny85 - 16.5MHz Digispark
;P0 : 
;P1 : 
;P2 : 
;P3 : SCL
;P4 : SDA
;P5 :

; .include "../includes/tn85def.inc"
; .define F_CPU 8000000 ;8MHz
; .def	A=R16
;.def	DATA=R20
;.def	ADR=R19

; .include 	"../utils/i2c_attiny.inc"
; .include 	"../utils/wait.inc"

; .dseg
; .org 0x100
; now: .byte 0x12
; date_txt: .byte 17 ;16 char
; temp_txt: .byte 6  ;5 char
; .cseg

.equ	DS3231		= 0x68	; DS3231 address byte
;________________________________________________________________
;DS3231 Init
;Registres utilisés : r16 (A),r19 (Adresse I²C=ADR), r20 (DATA),Z
;________________________________________________________________
; DS3131_Init:
	; ldi		ADR,DS3231*2	;Write Mode
	; rcall	I2CInit

	; LDI 	DATA,0		;set DS3231 register pointer to 00h
	; rcall	DATA_write_byte
	
;	sets time and date data to DS3231
	; ldi 	ZL, LOW(date<<1)
	; ldi		ZH, HIGH(date<<1)
	; rcall	DS3231_write_string
	; ret
	
; DS3231_write_string:
	; lpm 	DATA, Z+		;DATA=(Z) Z=Z+1
	; ser		A				;0xFF
	; cp		DATA,A			;Si egal fin
	; breq	DS3231_end_write		
	; rcall	DATA_write_byte		;Ecrire la donnée I2CWData
	; ldi		A, 2
	; rcall	WaitMiliseconds	;2ms
	; rjmp	DS3231_write_string
; DS3231_end_write:
	; ret	

;________________________________________________________________
;DS3231 Read ALL
;Registres utilisés : r16 (A),r19 (Adresse I²C=ADR), r20 (DATA),Z
;In : Nothing
;Out : now contient les données 
;________________________________________________________________
DS3231_read_all:
	; rcall	I2CInit
	 rcall	I2CStart
	 ldi	DATA,DS3231*2 ;Write Mode
	 rcall	I2CSendByte
	 ldi	DATA,0		  ;set DS3231 register pointer to 00h
	 rcall	I2CSendByte
	 rcall	I2CStop


;	rcall	I2CInit
	rcall	I2CDelay
	rcall 	I2CStart
	ldi		DATA,DS3231*2 | 1	;Read
	rcall	I2CSendByte
	ldi 	ZL, LOW(now<<1)
	ldi		ZH, HIGH(now<<1)
	ldi		R17,18	   ;18 données
recup:	
	ldi		DATA,0			;read with ACK
	rcall	I2CReadByte
	st		Z+,A
	mov		DATA,A
	dec		R17
	brne   recup
	
	ldi		DATA,1
	rcall	I2CReadByte		;read with NACK
	rcall	I2CStop			;Stop I2C
;________________________________________________________________	
;Converting date for display
;In Z pointer data
;Out : 08.11.2016 06:16 in date_txt
;________________________________________________________________
	ldi 	ZL, LOW((now<<1)+4) ;Day
	ldi		ZH, HIGH((now<<1)+4)
	ldi 	XL, LOW(date_txt<<1)
	ldi		XH, HIGH(date_txt<<1)
	
	rcall	DCB2ASC ;Day
	ldi		A,'.'
	st		X+,A
	adiw	ZL,1
	rcall	DCB2ASC ;Month
	ldi		A,'.'
	st		X+,A
	ldi		A,'2'
	st		X+,A
	ldi		A,'0'
	st		X+,A
	adiw	ZL,1
	rcall	DCB2ASC ;Year
	ldi		A,' '
	st		X+,A
	sbiw	ZL,4 	
	rcall	DCB2ASC ;Hour
	ldi		A,':'
	st		X+,A
	sbiw	ZL,1
	rcall	DCB2ASC ;MINUTE
	ser		A
	st		X,A	;0xFF en fin de chaine
	;ret

;________________________________________________________________
;Converting temp for display
;
;________________________________________________________________
conv_temp:
	adiw	ZL,0x10	;Temp
	ldi 	XL, LOW(temp_txt<<1)
	ldi		XH, HIGH(temp_txt<<1)
	ld		DATA,Z+
	ldi		A,'-'
	sbrs 	DATA,7
	ldi		A,'+'
	st		X+,A
	andi	DATA,0x7F
	mov		A,DATA
	rcall	bin2dcb
	ldi		A,',' ;partie decimal
	st		X+,A
	ldi		r17,25
	ld		DATA,Z+
	clr		A
	sbrc	DATA,7
	ldi		A,50
	sbrc	DATA,6
	add		A,r17
	rcall	bin2dcb
	ldi		A,1		;°
	st		X+,A
	ser		A		;End of string
	st		X+,A
	ret	
	
DCB2ASC:	
;DCB to ASC
	ld		A,Z ;A=0x08, 0x11,0x16...
DCB2ASC_A:
	mov		DATA,A
	andi 	DATA,0xF0 ;HIGH
	swap	DATA
	ori		DATA,0x30 ;NUM
	st		X+,DATA
	mov		DATA,A
	andi 	DATA,0x0F ;LOW
	ori		DATA,0x30 ;NUM
	st		X+,DATA
	ret
	
bin2dcb:			; maxi dec 99 
	clr DATA 		; digit count is zero
bin2dcba:
	cpi A,0x0A 		; bigger or equal decimal 
	brcs bin2dcbb 	; smaller than decimal (A < 10 )
	inc DATA 		; Increment digit count
	subi A,10 		; Subtract LSB decimal -10
	rjmp bin2dcba 	; Next loop
bin2dcbb:
	swap DATA
	or	A,DATA
	rcall DCB2ASC_A
	ret	
;date:	.db 	0,%MINUTE%,%HOUR%,0x6,%DAY%,%MONTH%,(%YEAR%-2000),0xFF