Remote control Pikachu

@DB7D

xor a
ld a,(d436) ; Pikachu will not move
or a ; unset carry flag
(did we press down?):
ld a,(ffb3) ; read joypad
sub a,80
cp a,01 ; did we press down?
jr c,(if yes: pressed down)
jr nc, (if no: did we press up?)
(pressed down): ld a,01
ld (d436),a ; Pikachu will move for one step
ld (d437),a ; Pikachu will move south
ret
(did we press up?):
ld a,(ffb3) ; read joypad
sub a,40
cp a,01 ; did we press up?
jr c,(if yes: pressed up)
jr nc, (if no: did we press left?)
(pressed up): ld a,02
ld (d437),a ; Pikachu will move up
dec a
ld (d436),a ; Pikachu will move for one step
ret
(did we press left?):
ld a,(ffb3); read joypad
sub a,20
cp a,01; did we press left?
jr c,(if yes: pressed left)
jr nc, (if no: did we press right?)
(pressed left): ld a,03
ld (d437),a ; Pikachu will move left
ld a,01 ;
ld (d436),a ; Pikachu will move for one step
ret
(did we press right?):
ld a,(ffb3); read joypad
sub a,10
cp a,01; did we press right?
jr c,(if yes: pressed right)
jr nc, (if no: did we press Select?)
(pressed right): ld a,04
ld (d437),a ; Pikachu will move right
ld a,01
ld (d436),a ; Pikachu will move for one step
ret
(did we press Select?):
ld a,(ffb3); read joypad
sub a,04
cp a,01 ; did we press Select?
jr c,(if yes: pressed Select)
jr nc, (if no: ret)
(pressed Select): xor a
ld (c1f1),a ; Pikachu returns
(ret):
ret

Change D36D/D36E to execute where you placed your code (e.g. DB7D)


RAW bytes for memory editing:

AF FA 36 D4 B7 FA B3 FF D6 80 FE 01 38 02 30 09 3E 01 EA 36 D4 EA 37 D4 C9 FA B3 FF D6 40 FE 01 38 02 30 0A 3E 02 EA 37 D4 3D EA 36 D4 C9 FA B3 FF D6 20 FE 01 38 02 30 0B 3E 03 EA 37 D4 3E 01 EA 36 D4 C9 FA B3 FF D6 10 FE 01 38 02 30 0B 3E 04 EA 37 D4 3E 01 EA 36 D4 C9 FA B3 FF D6 04 FE 01 38 02 30 04 AF EA F1 C1 C9

Change D36D/D36E to execute where you placed your code (e.g. to point to DB7D the bytes would be 7D DB)