# Tro u b l es h o ot i n g G u i d e

S e l ec t a t opi c belo w to tr oubleshoo t y ou r 3 DR cop t e r

.



# M o t o r s D on ’ t A r m ( D oub l e

- F l a s h i n g Y e l l o w S t a t u s

L E D )

T h e dou b le

- f lashin g y el l o w s t a t u s L ED indica t e s t ha t t h e d r o n e i s f ai l in g o n e o f t h e p r e

- a r m i n g sa f e ty c h ecks

.

T h e au t o p ilo t p e rf o r m s t hes e c heck s b e f o re e a c h f l i gh t to e n s u re t h a t al l s y s t e m s a r e op e r a t in g co rr ec t l y

. To

se e t h e sp e ci f i c e rr o r, c o nnec t to a g r ou n d s t a t io n an d v i e w t h e p r im a r y f l i gh t da t a dis p la y

.

G PS E r ro r :

T h e mos t commo n p r e

- a rm s a f e ty chec k e rr o r i s du e t o ins uf f ic i en t G P S signa l

. Y ou r d r on e r equi r e s a s tr on g

G PS si g na l to f l y accu r a t el y

. T he re a re t w o i mpo rt an t meas u r emen t s o f G PS sign a l r equ i r e d to p a s s t h e p r e

a rm c h eck : t h e G P S l oc k ( t h e s tr e n g th o f t h e si g nal ) an d t h e HD O P (t h e accu r a c y o f t h e s ig nal ).

A l oc k i s o b t aine d w h e n t h e G PS r ecei v e s p osi t i onin g da ta f r o m mu l t ipl e sa t e l li t e s

. Y o u ca n se e t h e s t a t u s o f

t h e lo c k a n d t h e n u mbe r o f c o mmun i ca t in g sa t el l i t e s o n t h e con tr o l le r ’ s f lig h t da ta d isp l a y

. ( Fo r I R IS+ a n d X 8 +

onl y

, p r es s an d ho l d t h e con t r o l le r ’ s D N bu t t o n to v ie w t h e f l igh t d a ta displa y .)

I R IS+ a n d X 8 + C on tr ol

l e r Fli gh t D a ta

F i v e o r mo re ac t i v e sa t e l li t e s w il l p r oduc e a s tr o n g G PS lo c k

. It i s p o ss i bl e f o r t h e G PS to acqu i re a loc k w i th

les s t ha n fi v e sa t el l i t es

, bu t t h e r e i s a g r ea t e r chanc e o f l o si n g t h e lo c k du r i n g f l i gh t w i th f e w e r sa t el l i t es

.

G ene r a l l y

, a cl e a r o f t h e sk y w i l l p r o duc e t h e hig h es t sa t el l i t e coun t, b u t i t ca n al s o dep e n d o n y ou r sp e ci f i c

loca t io n an d t h e t i m e o f d a y

. U s e t hi s t oo l to s e e h o w man y s a t el l i t e s a re p r ed i c t e d f o r y ou r f l y in g loca t ion

.H o r iz on t a l dil u t io n o f p r ec i sio n ( H D O P) i s a m e asu re o f t h e a ccu r a c y o f t h e G PS signal

, a s o p pose d to t h e

s tr eng th o f t h e sign a l a s mea s u r e d b y t h e lock

. T o pas s t h e p r e

- a rm ch e ck

, HD O P m u s t b e b elo w a speci f ie d

v alu e to ensu re a c cu r a te G PS measu r emen t s

. A hi g h H D O P ca n r esul t fr o m t h e p o si t i on s o f t h e sa t ell i t es

,

obs tr uc t ion s s u c h a s build i ng s an d mo u n t ains

, a t mosphe r i c e ff e c t s

, elec tr omagn e t i c i n t e rf e r enc e fr o m r adi o

t o w e r s o r on b oa rd r adi o tr an s mi s sio n e qui p men t, o r t h e t i m e o f da y

. Y o u c a n r ece i v e a n H D O P e rr o r e v e n w i th

a hig h numbe r o f sa t e lli t e s an d a n ac t i v e l ock

.

T o im p r o v e G PS sign a l

, mo v e to a mo re o p e n sp a c e w i th a c l e a r v i e w o f t h e sk y an d w a i t f o r t h e G PS to

acqu i re a n ac t i v e loc k o r a l o w e r HD O P.

R C C a libr a tion E r r or:

If t h e p r e

- a rm ch e c k f a ilu re s p ec i f ie s a n RC cal i b r a t io n e rr o r, us e M issio n P l anne r to r e

- pe r f o rm RC ca l ib r a t i o n

.

If y o u d o no t se e an y r esp o n s e i n t h e calib r a t io n sc r ee n f r o m m o v in g t h e c o n tr oll e r s t i cks

, ensu re t ha t bo th t h e

con tr o l le r an d t h e c o p t e r a r e p o w e r e d an d t h e cop t e r i s con n ec t e d t o the M issio n P l a nne r

. If y o u s t i l l d o no t

se e an y r espo n se

, f ol l o w the instructions in Reference 1

. (Ar d u pi l o t. co m t u t o r i al ) t o r e b in d t h e c on tr o l le r w i th

i ts r e cei v e r. Do no t p e rf o rm t h i s p r oces s unle s s y o u se e a n RC cal i b r a t io n e rr o r an d n o r e sp o ns e fr o m t h e

con tr o l le r w he n a t t emp t i n g to r e

- calib r a te us i n g M i ss i o n P la n n e r.

T u rn o n t h e c on tr ol l e r, an d p o w e r t h e co p t e r no r m a ll y

. N o w che c k t h e RC r ecei v e r ( pic t u r e d b el o w ); i f y o u don ’ t

se e a g r ee n L E D, f o l lo w t hes e s t ep s to r e

- bi n d t h e r e cei v e r to t h e t r a nsm i tt e r.

1

. D isconnec t t h e ba t t e ry fr o m t h e c o p t e r, an d t u rn o ff th e c on tr olle r. E n su re t h a t bo th t h e o n / o ff s w i t ch e s o n

t h e ba c k o f t h e co n tr olle r a r e s e t i n t h e d o wn posi t ion

. N o w h ol d do w n t h e F/S b u tt o n o n t h e bac k o f t h e

con tr o l le r, an d t u r n t h e con tr o ll e r o n w h i l e ho l d in g d o wn t h e b u t t on

.

C on t r o lle r2

. H ol d d o w n t h e F/S bu tt o n o n t h e r e cei v e r, an d connec t t h e b a tt e ry w h i l e h o l din g d o wn t h e bu t t on

.

R eceiv e r

3

. D isconnec t t h e ba t t e r y

, an d t u rn o ff t h e co n tr olle r. T he n t u rn o n t h e con tr ol l e r an d r e

- co n nec t t h e b a tt e r y

.

Y o u sho u l d s e e a g r ee n ligh t o n t h e r e cei v e r ind i ca t i n g t ha t i t i s conn e c t e d t o t h e con tr ol l e r. I f s o, r ea tt emp t

t h e p r e f ligh t s t e p s

.



# M o t o r s S p i n a t D i f f e r en t R a t e s

If t h e mo t o rs spi n a t di ff e r e n t r a t es

, y o u w i l l nee d to r e

- ca l ib r a te t h e ESC b y f o l lo w in g t h i s v ide o t u t o r ia l

( h tt p :// y ou t u

. be / s KB V a d R D c Ew ).

# U ne x p e c t e d o r I n c on si s t e n t F l i gh t B eha v i o r

S t e p 1 : E x amin e y ou r c o p t e r t o e n su re t h a t t h e compo n en t s a r e und a maged

. V e r i fy t ha t t h e p r op e lle rs a re i n

t h e co rr ec t o r de r o f SF an d SFP a s sho w n be l o w

. C h ec k t ha t al l p r ope l le rs ar e a tt ache d w i th t h e w r i t in g o n t h e

p r opel l e rs f acin g t h e s k y

.

X

8 + P r o

pell e r O r de r

S t e p 2 : Pr e s s t h e sa f e ty bu tt o n u n t i l b li n kin g r e d

, an d connec t t h e cop t e r to M issio n P l a n n e r o r APM P l a nne r

o n y o u r g r oun d s t a t io n com p u t e r, an d conn e c t t h e cop t e r t o M a v Lin k b y selec t in g C onn e c t. S el e c t I n i t ia l S e t u p

an d M a nda t o r y H a r d w a r e

, an d pe rf o rm a n acce l e r ome t e r cal i b r a t io n a s s h o wn i n the video tutorial

( h tt p :// y ou t u

. be / M

- gJ K _h e f k I). N e x t, pe rf o rm a compa s s cal ib r a t io n a s sho w n i n t h e v ide o t u t o r ia l

( h tt ps :/ / ww w

. y ou t u be

. com /w a t ch ? v =o D 9 Z 9 IR 2 TN U & f ea t u r e = y o u t u

. be ).

# Reference 1



# Radio Calibration

Autopilot calibration : calibrate your autopilot to work with your RC transmitter and receiver.



### • 1 Prerequisites



### • 2 Prepare transmitter



### • 3 Calibrate



# 1 Prerequisites

Before performing setup, ensure that:



### • The vehicle is completely built to flight condition.



### • Firmware has been loaded onto the autopilot.



### • Autopilot is connected to APM Planner and connected to Mavlink.



### • RC transmitter and receiver are bound and powered.



### • Propellers are removed.



# 2 Prepare transmitter

Turn on the transmitter, and verify that it is in airplane mode (APM needs airplane mode regardless of the platform type being

piloted) and all trims are centered.

For Mode 1 transmitters, the left stick will control pitch and yaw, the right stick will control throttle and roll. For Mode 2

transmitters, the left stick will control throttle and yaw; the right stick will control pitch and roll. For either type of t ransmitter, the

transmitter’s three

- position switch should be attached to channel 5 and will control flight modes.



# 3 Calibrate

Select Radio Calibration to teach your autopilot to work with your RC transmitter and receiver. Select Start Calibration to begin.

Read the instructions in the following prompt and select OK

.Select Start Calibration to begin. Move both sticks in the largest circle possible so that they reach their complete range of motion.

Move the Ch 5 and 6 toggle switches through their range of positions.

Your transmitter should cause the following control changes:

Channel 1: low = roll left, high = roll right.

Channel 2: low = pitch forward, high=pitch back.

Channel 3: low = throttle down (off), high = throttle up.

Channel 4: low = yaw left, hig h = yaw right.

Watch the red bars on the screen to ensure that the correct controls activate for each stick movement. If the red bars move i n the

opposite direction that you’re moving the sticks, you will need to reverse the channel on your transmitter. Se lect End Calibration

when complete. Resulting normal values are around 1100 for minimums and 1900 for maximums.