Piezo vibration detector to test with Leaky Faucet

piezoLeak.asm

;sound sensor program using piezo to detect a dripping faucet
;adapted from the footstep detector from AVR-Programming by Elliot Williams
;
;flash with avrdude -c avrisp -p m168 -P /dev/tty.usbmodem1411 -b 19200 -U flash:w:piezoLeak.hex
;
;use adc2 on PC2 for piezo input
; make sure to check registers before importing into ble program
.equ UBBRvalue = 12
.def temp = r16
.def count = r17
.def flags = r18        
.def byte_tx = r19      ;for serial transmit routine
.def xL = r26           ;x reg used as global counter
.def xH = r27
.def yL = r28
.def yH = r29
.def zL = r30
.def zH = r31
.device atmega168
;---- global variables ----
.equ L_FLG = 2          ;global leak flag
.equ C_FLG = 3          ;counter overflow flag
.cseg
.org 0
;----- Main -----
reset:
;inittialize Stack
        ldi     temp,low(RAMEND)
        out     SPL,temp
        ldi     temp,high(RAMEND)
        out     SPH,temp
;initialize USART
        ldi     temp,high(UBBRvalue)    ;baud rate param
        sts     UBRR0H,temp
        ldi     temp,low(UBBRvalue)
        sts     UBRR0L,temp
        lds     temp,UCSR0A
        ori     temp,(1 << U2X0)        ;set use 2x because %error actual baud > .5
        sts     UCSR0A,temp
;--- USART register values
        ldi     temp,(1 << TXEN0) | (1 << RXEN0) ;enable transmit and receive
        sts     UCSR0B,temp
        ldi     temp,(1 << UCSZ01) | (1 << UCSZ00) ;8 data bits, 1 stop bit
        sts     UCSR0C,temp
;--- init ADC ---
        sbi     DDRB,PB1
        lds     temp,ADMUX
        sbr     temp,(1 << REFS0)       ;use external avcc
        sts     ADMUX,temp
        lds     temp,ADCSRA
        sbr     temp,(1 << ADPS1) | (1 << ADPS2)        ;set clock prescale /64
        sbr     temp,(1 << ADEN)                        ;enable adc
        sts     ADCSRA,temp
;--- init variables ---
        ldi     xL,low(midval)
        ldi     xH,high(midval)
        ldi     temp,0xff       ;init midval to 511
        st      X+,temp
        ldi     temp,0x01
        st      X,temp
        ldi     xL,low(hival)
        ldi     xH,high(hival)
        ldi     temp,0x08
        st      X+,temp
        ldi     temp,0x02
        st      X,temp          ;init hival to 520 (0x0208)
        ldi     xL,low(loval)
        ldi     xH,high(loval)
        ldi     temp,0xf4
        st      X+,temp
        ldi     temp,0x01
        st      X,temp          ;init loval to 500 (0x01f4)
        ldi     xL,low(noise)
        ldi     xH,high(noise)
        ldi     temp,0x00
        st      X+,temp
        st      X,temp          ;init noise to 0
;--- start getting data ---
evt_lp: lds     temp,ADMUX
        sbr     temp,(1 << MUX1)
        sts     ADMUX,temp
        lds     temp,ADCSRA
        sbr     temp,(1 << ADSC)        ;start conversion
        sts     ADCSRA,temp
ad_lp:  lds     temp,ADCSRA
        sbrc    temp,ADSC
        rjmp    ad_lp
        ldi     xL,low(adcval)
        ldi     xH,high(adcval)
        lds     temp,ADCL
        st      X+,temp
        lds     temp,ADCH
        andi    temp,0b00000011
        st      X,temp
;--- calculate middle value ---
;  r22 = temp_L
;  r23 = temp_H
;  r24 = temp2_L
;  r25 = temp2_H
        ldi     xL,low(midval)
        ldi     xH,high(midval)
        ld      r24,X+
        ld      r25,X           ;high byte
        sbiw    r25:r24,8
        clc
        ldi     count,4
divlp:  lsr     r25
        lsr     r24
        clc
        dec     count
        brne    divlp
; r24:r25 contain ((midval - 8) >> 4)
; next subtract result from midval and add adcval
        ldi     xL,low(midval)
        ldi     xH,high(midval)
        ld      r22,X+          ;low byte in r23 to match result byte order
        ld      r23,X
        clc
        sub     r22,r24         ;subtract low byte of result from midval
        sbc     r23,r25         ;high byte with carry
; result in r22(low):r23(high)
        clc
        ldi     xL,low(adcval)
        ldi     xH,high(adcval)
        ld      r24,X+
        ld      r25,X
        clc
        add     r24,r22         ;add low bytes first
        adc     r25,r23         ;add highh bytes with carry
; store result in midval
        clc
        ldi     xL,low(midval)
        ldi     xH,high(midval)
        st      X+,r24
        st      X,r25
;done with first calculation, now compare
;midval is in r25:r24
        clc
        ldi     count,4
divlp2: lsr     r25
        lsr     r24
        clc
        dec     count
        brne    divlp2          ;divide midval by 16
;---- if adc > midval/16 do true ----
        ldi     xL,low(adcval)
        ldi     xH,high(adcval)
        ld      r22,X+
        ld      r23,X
        cp      r23,r25
        brsh    skp1
        rjmp    else            ;a < m
skp1:   clc
        cp      r23,r25
        brne    true            ;means  r23 is greater
        clc
        cp      r24,r22         ; if (a > m) == cp m,a brsh skip
        brsh    else
true:
;---- highval = adcval + highval - ((highval - 8) >> 4) ----
        ldi     xL,low(hival)
        ldi     xH,high(hival)
        ld      r25,X
        sbiw    r25:r24,8
        clc
        ldi     count,4
divlp3: lsr     r25
        lsr     r24
        clc
        dec     count
        brne    divlp3
; next subtract result from hival and add adcval
        ldi     xL,low(hival)
        ldi     xH,high(hival)
        ld      r22,X+          ;low byte in r23 to match result byte order
        ld      r23,X
        clc
        sub     r22,r24         ;subtract low byte of result from hival
        sbc     r23,r25         ;high byte with carry
; result in r22(low):r23(high)
        clc
        ldi     xL,low(adcval)
        ldi     xH,high(adcval)
        ld      r24,X+
        ld      r25,X
        clc
        add     r24,r22         ;add low bytes first
        adc     r25,r23         ;add highh bytes with carry
; store result in hival
        clc
        ldi     xL,low(hival)
        ldi     xH,high(hival)
        st      X+,r24
        st      X,r25
        rjmp    chk_adc
else:
;skip compare b/c its almost the opposite
;---- loval = adcval + loval - ((loval - 8) >> 4) ----
        ldi     xL,low(loval)
        ldi     xH,high(loval)
        ld      r24,X+
        ld      r25,X
        sbiw    r25:r24,8
        clc
        ldi     count,4
divlp4: lsr     r25
        lsr     r24
        clc
        dec     count
        brne    divlp4
; next subtract result from loval and add adcval
        ldi     xL,low(loval)
        ldi     xH,high(loval)
        ld      r22,X+          ;low byte in r23 to match result byte order
        ld      r23,X
        clc
        sub     r22,r24         ;subtract low byte of result from loval
        sbc     r23,r25         ;high byte with carry
; result in r22(low):r23(high)
        clc
        ldi     xL,low(adcval)
        ldi     xH,high(adcval)
        ld      r24,X+
        ld      r25,X
        clc
        add     r24,r22         ;add low bytes first
        adc     r25,r23         ;add highh bytes with carry
; store result in loval
        clc
        ldi     xL,low(loval)
        ldi     xH,high(loval)
        st      X+,r24
        st      X,r25
;---- next check adc to see if its above or below thresholds
chk_adc:
;--- first get noise volume ---
        ldi     xL,low(loval)
        ldi     xH,high(loval)
        ld      r24,X+
        ld      r25,X
        adiw    r25:r24,16              ;lowval + padding
        ldi     xL,low(hival)
        ldi     xH,high(hival)
        ld      r22,X+
        ld      r23,X
        clc
        sub     r22,r24
        sbc     r23,r25         ;highval - lowval + padding
        ldi     xL,low(noise)
        ldi     xH,high(noise)
        st      X+,r22
        st      X,r23
;now make compare
        ldi     xL,low(midval)
        ldi     xH,high(midval)
        ld      r24,X+
        ld      r25,X
        clc
        add     r24,r22
        adc     r25,r23         ;add noise+midval
        clc
        ldi     count,4
dvlp4:  lsr     r25
        lsr     r24
        clc
        dec     count
        brne    dvlp4
        ldi     xL,low(adcval)
        ldi     xH,high(adcval)
        ld      r22,X+
        ld      r23,X
        cp      r23,r25
        brsh    tstequ
        rjmp    nxt2
tstequ: clc
        cp      r23,r25
        brne    tru2
        clc
        cp      r24,r22
        brlo    nxt2
tru2:   ldi     byte_tx,0x48            ;'H'
        rcall   transmit
        sbi     PORTB,PB1
        mov     byte_tx,r23             ;adc H
        rcall   transmit
        mov     byte_tx,r22
        rcall   transmit
        rjmp    evt_lp
nxt2:   clc
        cp      r23,r25
        brne    lt
        cp      r22,r24
        brlo    lt
        ldi     byte_tx,0x01
        rcall   transmit
        mov     byte_tx,r23
        rcall   transmit
        mov     byte_tx,r22
        rcall   transmit
        rjmp    evt_lp
lt:     ldi     byte_tx,0x4c            ;'L'
        rcall   transmit
        cbi     PORTB,PB1
        mov     byte_tx,r23
        rcall   transmit
        mov     byte_tx,r22
        rcall   transmit
        rjmp    evt_lp
;*** Subroutines ***
transmit:
        lds     temp,UCSR0A
        sbrs    temp,UDRE0
        rjmp    transmit
        sts     UDR0,byte_tx
        ret
;variable data
.dseg
adcval: .byte 2
midval: .byte 2
hival: .byte 2
loval: .byte 2
noise: .byte 2
pad: .byte 1