alias dRadar d0
alias dLight d1 #diode slide
alias rVertDir r1
alias rHorDir r2
alias rHor r3
alias rVert r4
alias rStr r7
alias rPrevStr r8
alias rCurSig r10
alias rPrevSig r11
move rVertDir -1
move rHorDir 1
move rVert 80
move rHor 0
main:
s dLight On 0
s db Setting 1
mul r0 20 rHorDir
add rHor rHor r0
brgt rVert 30 3
move rVert 80
move rVertDir -1
jal _rangeCheck
jal _alignDish
l rCurSig dRadar SignalID
beqz rCurSig main #no signal, we keep looking
beq rCurSig rPrevSig main #already scanned, ignoring
s dLight On 1
push rVertDir
push rHorDir
push rVert
push rHor
search_loop:
jal _vertSeek
jal _horSeek
s dLight Setting rStr
wait_loop:
l r0 dLight On
beqz r0 exit_search
l r0 dRadar SignalStrength
bge r0 0.96 wait_loop
j search_loop
exit_search:
l rCurSig dRadar SignalID
move rPrevSig rCurSig
pop rHor
pop rVert
pop rHorDir
pop rVertDir
jal _alignDish
j main

_vertSeek:
push ra
s db Setting 2
l rHor dRadar Horizontal
l rVert dRadar Vertical
l rPrevStr dRadar SignalStrength
sub r0 1 rPrevStr
mul r0 r0 30
mul r0 r0 rVertDir
add rVert rVert r0
jal _rangeCheck
jal _alignDish
l rStr dRadar SignalStrength
brge rStr rPrevStr 2
mul rVertDir rVertDir -1
pop ra
j ra

_horSeek:
push ra
s db Setting 3
l rHor dRadar Horizontal
l rVert dRadar Vertical
l rPrevStr dRadar SignalStrength
sub r0 1 rPrevStr
mul r0 r0 30
mul r0 r0 rHorDir
add rHor rHor r0
jal _rangeCheck
jal _alignDish
l rStr dRadar SignalStrength
brge rStr rPrevStr 2
mul rHorDir rHorDir -1
pop ra
j ra

_rangeCheck:
brgt rHor 0 5
mul rHorDir rHorDir -1
s dLight On 0
move rHor 0
sub rVert rVert 30
brlt rHor 360 5
mul rHorDir rHorDir -1
s dLight On 0
move rHor 360
sub rVert rVert 30
brgt rVert 0 4
mul rVertDir rVertDir -1
s dLight On 0
move rVert 0
brle rVert 90 3
mul rVertDir rVertDir -1
move rVert 90
j ra

_alignDish:
s db Setting 4
round rVert rVert
round rHor rHor
s dRadar Vertical rVert
s dRadar Horizontal rHor
alignDishLoop:
l r5 dRadar Vertical
l r6 dRadar Horizontal
round r5 r5
round r6 r6
bne r5 rVert alignDishLoop
bne r6 rHor alignDishLoop
aligned:
l rVert dRadar Vertical
l rHor dRadar Horizontal
j ra