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device PIC16F84A,hs_osc,wdt_on,protect_off
VERSION = 11
ADCS = ra.0 ;A/D chip select
ADCLK = ra.1 ;A/D clock
ADDAT = ra.2 ;A/D data
org 12
w_save ds 1
s_save ds 1
data ds 1
del1 ds 1
del2 ds 1
count ds 1
sumlo ds 1
sumhi ds 1
qsumlo ds 1
qsumhi ds 1
temp ds 1
samps ds 1
dfacto ds 1
ref ds 1
chans ds 5 ;current level of each channel
org 0
goto start
org 4
inter movwf w_save ;save w register
swapf status,w ;reverse nibble of status
movwf s_save ;in status save
bcf status,5 ;now, force to primary registers
:end swapf s_save,w ;re-reverse status data
movwf status ;restore to status register
swapf w_save ;pre-swap w saved
swapf w_save,w ;swap into w without affection status
bcf INTCON,1 ;clear rb,0 int flag
reti ;enable global interrupt
start bsf STATUS,5 ;alt regs
movlw 00000000b ;
movwf TRISB
movlw 00100b
movwf TRISA
bcf STATUS,5
movlw 128
movwf ref
; find each channel level.
; in between each evalualtion, see if time to turn on each
; channel output (effectively PWM).
cycle movlw 40
call eval
movwf chans
movlw 0ffh
call lites
movlw 70
call eval
movwf chans+1
movlw 0fCh
call lites
movlw 130
call eval
movwf chans+2
movlw 0F0h
call lites
movlw 180
call eval
movwf chans+3
movlw 0C0h
call lites
movlw 250
call eval
movwf chans+4
movlw 080h
call lites
goto cycle
; as each channel volume achieves higher order bits,
; turn that channel on sooner in the sequence.
lites clrf rb
movwf temp
andwf chans,w
btfss z
bsf rb,1
movf temp,w
andwf chans+1,w
btfss z
bsf rb,2
movf temp,w
andwf chans+2,w
btfss z
bsf rb,3
movf temp,w
andwf chans+3,w
btfss z
bsf rb,4
movf temp,w
andwf chans+4,w
btfss z
bsf rb,5
ret
; delay loop proportional to 'w' squared
; location of watch dog timer reset
wsq movwf del1
:xx movwf del2
:yy clrwdt
nop
nop
nop
nop
nop
decfsz del2
goto :yy
decfsz del1
goto :xx
ret
; find level in one channel
; returns w-squared value (effectively making response exponential)
eval call dtmf
bcf c
rrf sumhi
rrf sumlo
rrf sumhi
rrf sumlo
rrf sumhi
rrf sumlo
bcf c
rrf qsumhi
rrf qsumlo
rrf qsumhi
rrf qsumlo
rrf qsumhi
rrf qsumlo
movf sumlo,w
call square
movwf data
movf qsumlo,w
call square
addwf data,w
ret
; perfoms FFT on audio signal - returns w-sqwared value.
; note: low sample count creates wide bandwidth.
dtmf movwf dfacto
movlw 2 ;increase bandwidth(11)
movwf samps
clrf sumlo
clrf sumhi
clrf qsumlo
clrf qsumhi
:x2 call :xgo
call sadsum
call :xgo
call sadqsm
call :xgo
sublw 0
call sadsum
call :xgo
sublw 0
call sadqsm
decfsz samps
goto :x2
ret
:xgo movf dfacto,w
call micro
call atod
subwf ref,w
ret
micro movwf del1
:mdx nop
nop
nop
nop
;
nop
nop
nop ;lower freq response(11)
decfsz del1
goto :mdx
ret
; adds 2's compliment value in 'w' to sumlo/sumhi.
sadsum movwf temp
btfss temp,7
goto :add1
addwf sumlo
btfss c
decf sumhi
ret
:add1 addwf sumlo
btfsc c
incf sumhi
ret
; same as above for qsumlo/qsumhi.
sadqsm movwf temp
btfss temp,7
goto :add1
addwf qsumlo
btfss c
decf qsumhi
ret
:add1 addwf qsumlo
btfsc c
incf qsumhi
ret
; reads ADC0831 serial d/a
atod bcf ADCS ;CS low
clrf data ;clear data byte
bsf ADCLK ;first clock
bcf ADCLK
bsf ADCLK ;second clock
bcf ADCLK
movlw 8 ;set bit count
movwf count ;into count
bcf status,0 ;clear carry bit
atod2 rlf data ;hi order is first
bsf ADCLK ;clock hi
btfsc ADDAT ;test input bit
bsf data,0 ;if hi - set data bit
bcf ADCLK ;clock low
decfsz count ;8 times
goto atod2
bsf ADCS ;CS hi
movf data,w ;data in w
ret
; (for test purposes only)
pulse movwf temp
bsf rb,0
:p2 decfsz temp
goto :p2
bcf rb,0
ret
org 100h
; performes squaring operation on 'w' - returns 8 bit value in 'w'.
square movwf temp
btfsc temp,7
comf temp
movf temp,w
clrf PCLATH
bsf PCLATH,0
addwf PCL
retw 000,000,000,000,000,000,000,000
retw 001,001,001,001,002,002,003,003
retw 004,004,005,005,006,006,007,008
retw 009,009,010,011,012,013,014,015
retw 016,017,018,019,020,021,022,023
retw 025,026,027,028,030,031,033,034
retw 036,037,039,040,042,043,045,047
retw 049,050,052,054,056,058,060,062
retw 064,066,068,070,072,074,076,078
retw 081,083,085,087,090,092,095,097
retw 100,102,105,107,110,112,115,118
retw 121,123,126,129,132,135,138,141
retw 144,147,150,153,156,159,162,165
retw 169,172,175,178,182,185,189,192
retw 196,199,203,206,210,213,217,221
retw 225,228,232,236,240,244,248,252
end
