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.include "tn85def.inc"
.def tmp0 = r16
.def tmp1 = r17
.def tmp2 = r18
.def tmp3 = r19
; Interrupt vectors
.org 0x0000
interrupts:
rjmp init
.org ADCCaddr
rjmp adc_isr
.org INT_VECTORS_SIZE
init:
; Initialize stack pointer
ldi tmp0, HIGH(RAMEND)
out SPH, tmp0
ldi tmp0, LOW(RAMEND)
out SPL, tmp0
; Set pin directions
ldi tmp0, 0b00010010
out DDRB, tmp0
; Set default outputs
;ldi tmp0, 0b00000010
;out PORTB, tmp0
; Initialize timer 0B
ldi tmp0, 0b00100011
out TCCR0A, tmp0
ldi tmp0, 0b00000001
out TCCR0B, tmp0
; Initialize timer 1B
ldi tmp0, 0b00000001
out TCCR1, tmp0
ldi tmp0, 0b01100000
out GTCCR, tmp0
; Enable interrupts
ldi tmp0, 0b10000000
out SREG, tmp0
; Initialize ADC
ldi tmp0, 0b01000001
out ADMUX, tmp0
ldi tmp0, 0b10101000
out ADCSRA, tmp0
; Start ADC conversion
sbi ADCSRA, ADSC
main:
rjmp main
adc_isr:
push tmp0
push tmp1
; Read out ADC
in tmp0, ADCL
in tmp1, ADCH
; Substract offset
subi tmp0, LOW(638)
sbci tmp1, HIGH(638)
; Normalize to 8 bit for timer
lsr tmp1
ror tmp0
lsr tmp1
ror tmp0
; Set as timer compare
out OCR0B, tmp0
com tmp0
out OCR1B, tmp0
pop tmp1
pop tmp0
reti
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