;**********************
;Including Controller Definetion File
;**********************

.include "2313def.inc"

;**********************
;Description
;**********************
;The connection details are as given in schematic
;LCD is connected to port B and sensor is connected
;to INT 0 pin of MCU

;**********************
;calculation Details (Formulae Used)
;**********************

;####For speed measurement####
;speed = 2*pi*R*3600*clk/time_count*1000*x
;R = radius of the wheel in cm (In this design R=25cm)
;time_count = value of timer counter in b/w
;two successive interrupts
;x = clock prescaler used (in this design x=1024)
;using this we have calculated the equivalent value of
;all the constants (except time_count all other parameters
;are constants)
;sh and sl are binary equivalent of this constant

.equ sh = $56
.equ sl = $49   
.equ sht = $57          ;sht = sh + 1

;####For distance measurement####
;After every 100 m the registers holding distance values
;are incremented. For this we have used following formulae
; 2*pi*R*n/100 = 100
;R = radius of the wheel in cm (In this design R=25cm)
;n is the count which signifies that 100 m has been completed

.equ n = $40

;********************
;To give useful names to Registers
;********************

;####temporay registers####
.def temp=r16          
.def temp1=r18         
.def c1=r22             ;used for speed calculation and for display purpose
.def c2=r4              ;used for speed calculation and for display purpose
.def d1=r5              ;used for speed calculation and for display purpose
.def d2=r6              ;used for speed calculation and for display purpose
.def status=r7  ;holds the value of status register in case of interrupt

;####Registers used for timing####
.def count_1=r17        ;
.def time_1=r1         
.def time_0=r2

;####Registers used for speed measurement####
.def sdigit_01=r19
.def sdigit_1=r20       ;holds the binary value of speed

;####Registers used for Distance measurement####
.def ddigit_01=r8       ;Holds binary value of distance (0.0 to 9.9)
.def ddigit_1=r9        ;Holds binary value of distance (10.0 to 999.9)
.def ddigit_10=r10      ;Holds binary value of distance (1000.0 to 99999.9)
.def dist_count=r13

;####Registers used for LCD display####
.def lcd_cmd=r21
.def lcd_dat=r23
.def count=r3

;####Registers used for delays####
.def low_del=r24
.def hi_del=r25

;####Registers used for EEPROM####
.def eep_reg=r11
.def eep_addr=r12

;r14r15

;*******************
;Code Segment
;*******************

.cseg          

.org 0         
    rjmp    RESET          
         
.org INT0addr
        rjmp IntV0

reti
reti
reti
reti
       
.org OVF0addr
        rjmp TimerV0
       
reti
reti
reti
reti

.org $000b

;*******************
;Reset interrupt subroutine
;to be executed on Reset interrupt
;*******************
       
RESET:

;####Initializing Stack Pointer####

        ldi temp,RAMEND
    out SPL, temp        

;####Initializing I/O Ports####

    ldi temp, 0b11111111   ;configure PORT B for all outputs
    out DDRB, temp  
    ldi temp,0
    out DDRD,temp
    ldi temp,$ff
    out PORTD,temp              ;configure PORT D for all inputs      

;####Initializing INT 0 interrupt####
        ldi temp,$40            ;Enabling INT 0 interrupt
        out GIMSK,temp
        ldi temp,$03            ;Interrupt on rising edge
        out MCUCR,temp

;####Intializing timing process####
        ldi temp,$02
        out TIMSK,temp          ;Enabling timer overflow interrupt
        ldi temp,$05
        out TCCR0,temp
       
        ldi temp,$00            ;Initializing Registers
        out TCNT0,temp
       
        clr time_0
        clr time_1

;####Initializing registers holding speed####
        clr sdigit_1
        clr sdigit_01

;####Initializing registers holding distance####
        clr dist_count
        clr ddigit_01
        clr ddigit_1
        clr ddigit_10
        rcall eeprom_read
       
;####Initializing LCD Display####
        rcall init_lcd
        rcall init_lcd
        rcall hi_delay

;####enabling global mask interrupt enable####
        sei

;********************
;Main Part of the Program
;********************

main_loop:
        rcall dist              ;Subroutine to calculate Distance
        rcall print_lcd ;Subroutine for LCD Display
        rjmp main_loop  

;********************
;INT 0 ISR
;********************

IntV0:
        in status,SREG
        in time_0,TCNT0
        mov time_1,count_1
        clr count_1
        out TCNT0,count_1
        inc dist_count
        rcall speed             ;Subroutine for speed calculation
        out SREG,status
        reti

;********************
;Timer overflow ISR
;********************

TimerV0:
        in status,SREG
        inc count_1
        cpi count_1,sht
        brsh timeff
        out SREG,status
        reti

timeff:
        clr count_1
        rcall time00
        ret
       

;********************
;Calculation of speed
;********************

speed:
        push d1
        push d2
        push c1
        push c2
        ldi temp1,$00
        cp time_1,temp1
        breq time0     
speedq:
        clr sdigit_1
        ldi temp1,sh
        mov c1,temp1   
        ldi temp1,sl
        mov c2,temp1   
        rjmp speedcal

time0:
        cp time_0,temp1
        breq time00
        rjmp speedq

time00:
        clr sdigit_1
        clr sdigit_01
        pop d1
        pop d2
        pop c1
        pop c2
        ret
       
speedcal:
        cp c1,time_1
        brsh speed_cal
        rjmp speed0
speed_cal:
        cp c2,time_0
        brsh speed_cal1
        cp c1,time_1
        breq speed0
        rjmp speed_cal2
speed_cal1:
        inc sdigit_1
        sub c1,time_1
        sub c2,time_0
        rjmp speedcal

speed_cal2:
        inc sdigit_1
        sub c1,time_1
        sub c2,time_0
        dec c1
        rjmp speedcal

speed0:
        rjmp scal
scal:
        mov d1,c1
        mov d2,c2
        ldi temp1,10
        rjmp scal1
scal1:
        cpi temp1,1
        brne scal2
        rjmp scal3
scal2:
        dec temp1
        add d2,c2
        adc d1,c1
        rjmp scal1
scal3:
        cp d1,time_1
        brsh scal4
        rjmp speed1
scal4:
        cp d2,time_0
        brsh scal5
        cp d1,time_1
        breq speed1
        rjmp scal6
scal5:
        inc sdigit_01
        sub d1,time_1
        sub d2,time_0
        rjmp scal3
scal6:
        inc sdigit_01
        sub d1,time_1
        sub d2,time_0
        dec d1
        rjmp scal3
speed1:
        pop d1
        pop d2
        pop c1
        pop c2
        ret
       
;********************
;Calculation of distance
;********************

dist:
        ldi temp1,n     
        cp dist_count,temp1
        brsh dist_cal
        ret
dist_cal:
        clr dist_count
        inc ddigit_01

        ldi temp,1
        mov eep_addr,temp
        mov eep_reg,ddigit_01
        rcall eeprom_write
       
        ldi temp1,100
        cp ddigit_01,temp1
        brsh dist_cal1
        ret
dist_cal1:
        clr ddigit_01
        inc ddigit_1
       
        ldi temp,1
        mov eep_addr,temp
        mov eep_reg,ddigit_01
        rcall eeprom_write
        ldi temp,2
        mov eep_addr,temp
        mov eep_reg,ddigit_1
        rcall eeprom_write
       
        ldi temp1,100
        cp ddigit_1,temp1
        brsh dist_cal2
        ret
dist_cal2:
        clr ddigit_1
        inc ddigit_10
       
        ldi temp,1                              ;storing data to EEPROM
        mov eep_addr,temp
        mov eep_reg,ddigit_1
        rcall eeprom_write
        ldi temp,2
        mov eep_addr,temp
        mov eep_reg,ddigit_01
        rcall eeprom_write
        ldi temp,3
        mov eep_addr,temp
        mov eep_reg,ddigit_10
        rcall eeprom_write
       
        ldi temp1,100
        cp ddigit_10,temp1
        brsh dist_cal3
        ret
dist_cal3:
        clr dist_count
        clr ddigit_01
        clr ddigit_1
        clr ddigit_10
        ret


;********************
;Initializes distance registers values to
;previously stored value in EEPROM
;********************
eeprom_read:

        cli
        push temp
        ldi temp,1
        mov eep_addr, temp
        rcall eep_nr
        mov ddigit_01, eep_reg

        ldi temp,2
        mov eep_addr, temp
        rcall eep_nr
        mov ddigit_1, eep_reg

        ldi temp,3
        mov eep_addr, temp
        rcall eep_nr
        mov ddigit_10, eep_reg

        pop temp
        sei
        ret

;********************
;Subroutine to read data from eeprom
;eep_addr holds the address of eeprom
;eep_reg holds the data read
;********************
eep_nr:
        sbic EECR,EERE
        rjmp eep_nr
read:
        out EEAR, eep_addr
        sbi EECR, EERE
        nop
        nop
        in eep_reg, EEDR
        ret

;********************
;Subroutine to write data to eeprom
;eep_addr holds the address of eeprom
;eep_reg holds the data to be written
;********************
eeprom_write:
        sbic EECR, EEWE
        rjmp eeprom_write
write:
        out EEAR,eep_addr
        out EEDR,eep_reg
        cli
        sbi EECR,EEMWE
        sbi EECR,EEWE
        sei
        ret

;********************
;Init_Lcd: Initializes the 16 X 2 LCD module in 4 bit data
;transfer mode
;********************
init_lcd:
    ldi lcd_cmd, 3
    rcall lcd_low_cmd
    rcall hi_delay

    ldi lcd_cmd, 3
    rcall lcd_low_cmd
    rcall low_delay

    ldi lcd_cmd, 3
    rcall lcd_low_cmd
    rcall low_delay
 

    ldi lcd_cmd, $28    ; set 4-bit interface
    rcall lcd_all_cmd
         
    ldi lcd_cmd, 8              ; set DDRAM address to 00
    rcall lcd_all_cmd

    ldi lcd_cmd, $0c   
    rcall lcd_all_cmd

    ldi lcd_cmd, 6
    rcall lcd_all_cmd   ; mode setting
    ret

;********************
;Print_Lcd: Prints speed and distance on the LCD display module
;********************

print_lcd:

        ldi lcd_cmd, $80
    rcall lcd_all_cmd
       
        ldi temp, 16
    mov count, temp
    ldi ZH, high(msg1*2)
    ldi ZL, low(msg1*2)

more1:
        lpm
    mov lcd_dat, r0
    rcall lcd_all_dat
    adiw ZL, 1
    dec count
        ldi temp, 0
    cp count, temp
    brne more1

    ldi temp, 16
        mov count,temp
    ldi lcd_cmd, $c0
    rcall lcd_all_cmd
more2:  
        lpm
    mov lcd_dat, r0
    rcall lcd_all_dat
    adiw ZL, 1
    dec count
        ldi temp, 0
    cp count, temp
    brne more2

;####Binary to BCD conversion####
        clr d2
speeddigit:                             ;hundredth place value of speed
        cpi sdigit_1,100
        brsh sdigit_cal
        rjmp print1
       
sdigit_cal:
        inc d2 
        subi sdigit_1,100
        rjmp speeddigit 
       
print1:
        ldi lcd_cmd,$86
        rcall lcd_all_cmd
        mov lcd_dat,d2
        andi lcd_dat,$0f
        ori lcd_dat,$30
        rcall lcd_all_dat
        rcall low_delay

        mov c1,sdigit_1
        rcall bcd
        mov sdigit_1,c1
        mov c2,d1

        ldi lcd_cmd,$87         ;tenths place value of speed
        rcall lcd_all_cmd
        mov lcd_dat,c2
        andi lcd_dat,$0f
        ori lcd_dat,$30
        rcall lcd_all_dat
        rcall low_delay
       
        ldi lcd_cmd,$88         ;units place value of speed
        rcall lcd_all_cmd
        andi sdigit_1,$0f
        mov lcd_dat,sdigit_1
        ori lcd_dat,$30
        rcall lcd_all_dat
        rcall low_delay
                       
        ldi lcd_cmd,$8a         ;decimal place value of speed
        rcall lcd_all_cmd
        andi sdigit_01,$0f
        mov lcd_dat,sdigit_01
        ori lcd_dat,$30
        rcall lcd_all_dat
        rcall low_delay

;####prints distance####

        mov c1,ddigit_10
        rcall bcd

        ldi lcd_cmd,$c5         ;ten thousandth place of distance
        rcall lcd_all_cmd
        rcall low_delay
        mov lcd_dat,d1
        andi lcd_dat,$0f
        ori lcd_dat,$30
        rcall lcd_all_dat
        rcall low_delay


        ldi lcd_cmd,$c6         ;thousandth place of distance
        rcall lcd_all_cmd
        rcall low_delay
        mov lcd_dat,c1
        andi lcd_dat,$0f
        ori lcd_dat,$30
        rcall lcd_all_dat
        rcall low_delay

        mov c1,ddigit_1
        rcall bcd

        ldi lcd_cmd,$c7         ;hundredth place value of distance
        rcall lcd_all_cmd
        rcall low_delay
        mov lcd_dat,d1
        andi lcd_dat,$0f
        ori lcd_dat,$30
        rcall lcd_all_dat
        rcall low_delay

       
        ldi lcd_cmd,$c8         ;Tenth place value of distance
        rcall lcd_all_cmd
        rcall low_delay
        mov lcd_dat,c1
        andi lcd_dat,$0f
        ori lcd_dat,$30
        rcall lcd_all_dat
        rcall low_delay
       
        mov c1,ddigit_01
        rcall bcd

        ldi lcd_cmd,$c9         ;Units place value of distance
        rcall lcd_all_cmd
        rcall low_delay
        mov lcd_dat,d1
        andi lcd_dat,$0f
        ori lcd_dat,$30
        rcall lcd_all_dat
        rcall low_delay
       
        ldi lcd_cmd,$cb         ;decimal place of distance
        rcall lcd_all_cmd       
        rcall low_delay
        mov lcd_dat,c1
        andi lcd_dat,$0f
        ori lcd_dat,$30
        rcall lcd_all_dat
        rcall low_delay
       
        ret

;********************
;Binary to BCD conversion
;********************
bcd:
        clr d1
bcddigit:                      
        cpi c1,10
        brsh bcd_cal
        ret
       
bcd_cal:
        inc d1 
        subi c1,10     
        rjmp bcddigit


;********************
;Low_Delay: A 250 us delay
;********************
low_delay:
        push low_del
        push hi_del
    ldi low_del, 20
ld_hi:  
        ldi hi_del, 10
loop_in:
    dec hi_del
    cpi hi_del, 0
    brne loop_in
    dec low_del
    cpi low_del, 0
    brne ld_hi
    pop hi_del
    pop low_del
    ret

;********************
;Hi_Delay: A 5 ms delay
;********************
hi_delay:
    ldi low_del, 25
more_call:
    rcall low_delay
    dec low_del
    cpi low_del, 0
    brne more_call
    ret

;********************
;Lcd_Low_Cmd: Sends a command to higher 4 bits of the LCD.
;The command nibble must be in the lower nibble of the
;variable 'lcd_cmd'
;********************
lcd_low_cmd:
    mov temp, lcd_cmd
    lsl temp
    lsl temp
    lsl temp
    lsl temp
    andi temp, $f0
    out PORTB, temp
    ori temp, $08
    out PORTB, temp
    andi temp, $f7
    out PORTB, temp
    ret

;********************
;Lcd_All_Cmd: sends an 8 bit command to the LCD
;********************
lcd_all_cmd:
    push lcd_cmd
    lsr lcd_cmd
    lsr lcd_cmd
    lsr lcd_cmd
    lsr lcd_cmd
    rcall lcd_low_cmd
    pop lcd_cmd
    andi lcd_cmd, $0f
    rcall lcd_low_cmd
    rcall low_delay
    ret

;********************
;Lcd_All_Dat: Sends a data byte to the LCD. The data byte
;is stored in variable 'lcd_dat'
;********************
lcd_all_dat:
    push lcd_dat
    lsr lcd_dat
    lsr lcd_dat
    lsr lcd_dat
    lsr lcd_dat
    andi lcd_dat, $0f
    rcall lcdlowdat
    pop lcd_dat
    andi lcd_dat, $0f
    rcall lcdlowdat
    rcall low_delay
    ret

;********************
;Lcd_Low_Dat: Sends a data nibble to higher 4 bits of the
;LCD. The data nibble must be in the lower nibble of the
;variable 'lcd_dat'
;********************
lcdlowdat:
    mov temp, lcd_dat
    lsl temp
    lsl temp
    lsl temp
    lsl temp
    andi temp, $f0
    ori temp, $04
    out PORTB, temp
    ori temp, $08
    out PORTB, temp
    andi temp, $f7
    out PORTB, temp
    ret

;********************
;Message #1
;********************
msg1: .db "SPEED=   . Km/hrDIST=     . Km  "
;          12345678123456781234567812345678