iNav Sirius™ AIR3 F3 SPI - Fixed Wing FPV Mission version, includes M8N GPS / Compass - iNav 1.6.1 is the newest 2017 codebase to cater for auto-launch, stabilised flight, navigation, return to land (or Return to Loiter above you in an orbit) and uses a Google Chrome Extension UI, making it easy to connect, adjust and customise settings from your Mac or PC laptop using USB. Importantly for FPV Sirius™ AIR3 iNAV features OSD Tx/Rx pins externally to provide data to a MWOSD Minum such as Andromeda. The M8N GPS firmware has been specifically re-coded by us for iNav to suit both southern hemisphere and northern users.
Sirius™ Air3 + GPS Hardware Features or Airplanes
iNav 1.6.1 Software
Features we like about iNav 1.6.1 software
Training on iNav setup
iNAV USB Port connection - be sure the port selected is the USB port PC=Comm or ; Mac OSX = /dev/cuSLAB_USB - set speed to 115200 baud
iNAV Accelerometer Calibration (SETUP TAB) Calibrate button must be clicked 6 times for INERTIAL - so each time the AIR3 must be be in the 6 sequence different of assigned positions - hold until it shows completed in the log (USB arrow = front) 1. top of case up towards sky ; 2. flip upside down ; 3. on right side ; 4. with nose-up ; 5. on left side ; 6. with nose-down
iNAV Compass Calibration (only used for multicopters Quads,Avatar or Tricopters in iNAV - see SET UP TAB ; Note that fixed wing can only fly forward so heading is derived from GPS data in All iNAV fixed wings) - For Quads - after pressing calibrate mag rotate the AIR3/Quad with GPS/Compass pod fitted by 360° in 3 axis X, Y and Z within 30 secs
Team CarbonBird™ iNAV FAQ ©
My iNav F3 AIR3 won't arm - all the servos are dead ; Answer = iNav will not activate servos if the Receiver is either not on and powered/connected or not sending safe data from the Tx to the AIR3. Check your selected Rx is set (such as Serial Rx SBus or for older Rx with multiwire setting choose PWM Rx one-wire-per-channel) Additionally the AIR3-iNav wont ARM if any of the ARM blockers are active such as 1. GPS home point not recorded (you are inside or next to a large building or tree) 2. Tilted IMU 3. Throttle not below 1100 uSecs 4. Gyro was moving around in first 10 secs after power applied. 5. 6-position ACC calibration not completed 6. Compass not calibrated in 360° XYZ, clear of ferrous objects 7. Throttle not below min throttle (usually this means 1090 or less)
What is iNav Airmode? Answer = We recommend you set Airmode in config panel of UI tabs, to always ON - this will provide servo flight control surfaces IMU responses when gliding with throttle at 0% ; with Airmode = off setting a zero throttle setting will disable the servos.
Do i need to put my GPS on a lollypop stick? Answer = No - absolutely NOT - this is a myth started by people whose airframes are poorly conceived, full of vibration, RMI and RFI - We STRONGLY recommend you twist then route servo, ESC and the GPS lead "Wires" and pod >75mm away from other devices like ESC, OSD, FPV cams, uBECs, motor wires and LiPo wires. The GPS works in conjunction with a compass (in quads) and its usually the compass which is spiking due to RMI. However RMI can also be accidentally "injected" into un-twisted signal wires such as GPS wires creating very high signal/noise ratios in poor builds which ignore our wire routing advice above. Whilst a stick might comply with the 75mm clear rule, it's a sad fix as the lead wire may still be routed poorly. Far better to twist wires with GND wire - plan your wire paths and embed the GPS/Compass into the wing on the opposite side to the FPV Tx, and clear of the wing servos.
How do i alter the direction of my Wing Servos? Answer = Go to the iNav UI SERVOS tab and select "Enable Live Mode" - on the right side for say Servo 3 - in the column marked "Direction and rate" change the drop-down Rate from +100% - to -100% then press SAVE
iNav Failsafe - Should i set Failsafe on my Rx or in iNav? Answer = Failsafe is a MODE setting in MODES tab of UI - If you have a digital Rx like X4R or X8R you should be sure to use and assign FAILSAFE rather than RTH as a mode in MODES tab; then in FAILSAFE TAB of UI - choose your preferred Failsafe action such as return to Land ; Take your prop off - and walk about 10-15m away from home point to test failsafe is working the way you expect when you turn the Taranis OFF/ON again Be aware :-
I want to use an RC wing or a RC Delta fixed Wing with Rudder? My servo is not moving on Ch 5? Answer = When flying a turn without rudder you will encounter adverse YAW - Using a Rudder(s) permits fast recovery from a spin, the joy of doing perfect stall turns, holding the nose up in a slow roll or 4 point rolls/harriers with a delta, permits a crab approach to hold runway centreline in a crosswind, flatter (reduced bank) turns, balanced turns and is desirable for Photogrammetry ops. To active rudder in iNAV WING You must paste the code below into the WING cli and SAVE (essentially creating a custom mix with Rudder on pin 5 of AIR3) ; Then connect the Rudder servo (or two Rudder servos on a Y-Lead) as shown below (signal wire on M5 ; Servo GND/Vcc on Q2) - This is because the centre pins under M5 and M6 are OSD Tx/Rx data pins and not Vcc.set mixer CUSTOMAIRPLANE mmix resetmmix 0 1.000 0.000 0.000 0.000mmix 1 1.000 0.000 0.000 0.000 smix resetsmix 0 3 0 100 0 0 100smix 1 3 1 100 0 0 100smix 2 4 0 -100 0 0 100smix 3 4 1 100 0 0 100smix 4 5 2 100 0 0 100 save
My flying area has lots of obstacles - so I want my Wing to retun home - but only to circle above the trees and not try to land? Answer = in cli set nav_rth_allow_landing = OFF - this way your wing will circle around the home point at the altitude set for the RTH. You can also disable the RTH climb threshold if you prefer that is your decision option set nav_rth_climb_first = OFF
What is the profile of the AUTO_RTL Landing phase? Answer = Current 1.6.1 fixed wing autoland is to a) return to home position at RTH altitude - so if you want it to return at 50m set nav_rth_altude=5000 b) circle, Loiter and descend in a spiral descent using a 50m radius of the home point - you can change the radius so if you want 60m set nav_fw_loiter_radius=6000 . This caters for the pilot to regain control during orbit (move Tx sticks) and fly it (or if Tx power lost - to get another batter installed in his Tx)
I have only ever flown Quads - Whats the best way to wire up servos in a fixed wing RC plane? Answer = Be sure to use a high quality uBEC. Many older RC uBECs produce 5.4v and are not ideal for flight computers or OSD ; Choose a uBEC with sufficient AMPS to power fast servos, and a stable 5.00v output with no electrical noise. Fixed wing FPV (camera based ops) requires fast digital coreless servos or your wings are going to waggle all over the place; it's pointless having an F3 Arm chip CPU running at 8K and some old analogue blue plastic servos ! - Be sure to use FAST coreless digital servos and set the respective speed in the CONFIG tab of INav. Fixed wing RC ESCs should be selected for FPV for endurance - ie better efficiency using Active Freewheel.
My iNav plane rolls weird - kinda corkscrews and rolls ? How do i set the servos for linear rolls along the roll axis? Answer = In regard to the Servos - be sure to understand mechanical Aileron differential to provide more up aileron than down aileron, in a balanced roll. This is done by positioning the Servo arms (for top mounted servos only) leaning towards the back slightly 110° rather than 90° to the servo - if your servos are on the bottom of the wing the Aileron servo arms should be mounted with the horn leaning forwards at 70° to the servo rather than at 90°.
Should i do a hand launch at a steep angle upwards - throw it up? or should i throw it level? Answer = Risk management. It is much safer to throw an airplane LEVEL with the correct C of G set (and elevons up ~4mm for a wing) as the airplane will glide once it is thrown fast and level, provided airspeed exceeds stall speed at low angles of attack (ie level throw and elevons up - for a plane with elevator the elevator should be level or slightly up) - If you decide to throw the airplane upwards, or a friend throws it too soft - there is a strong risk it will never achieve flying airspeed - stall - drop a wing and crash, before the motor can accelarate the craft back to flying speed. So overall the safest maiden strategy is a good strong/hard & Level throw - overhand - so it's being thrown at 2m into the wind. Alternative method is a DLG style toss - however the iNAV software will cancel any throw exceeding 45° tilt.
I really want to use iNav auto-launch but am worried my WING will be damaged on the first throw? What is there to know to get this right? Answer = Never install the prop until you are 100% sure of the system and test it live WITHOUT a prop. Wear eye protection and a strong leather glove. We setup Auto-Launch and pass-thru on the same switch so if there is an issue its easy to switch into pass-thru and fly manually - then set this into MODES tab. Pick your weather and time for a maiden, wind is your friend. Always throw the maiden into a decent headwind ; for zero ground speed a wind will automatically give you 10-15kph of airspeed on the throw. Dead calm days are much harder to get a safe hand launch especially of a faster wing like a Zephyr. establish the C of G - mark it with a pen or a few dots of CA like brail. check the C of G . All Wings glide level with a slight amount of reflex = elevons about 4mm UP - then on Tx Set switch for ANGLE MODE - place the wing on the ground 1.place the Tx on the ground well clear (3-4m) of where you are going to step (this also ensures Taranis remains bound at 100%, as when the Tx is too close to the Rx the swamping will cause Taranis to go to failsafe and the launch detect will fail ) - Set throttle to zero, down full. 2. Flip your Auto Launch switch to ON 3. Set ARM switch to ON (the Acc is now waiting to detect "G" force - so be very careful at this point not to jerk the airplane around) Also DO NOT bump your STICKS during launch!! if the sticks are now bumped the launch is effectively cancelled 4. Move your throttle up to approx 75%, the motor should not spin yet (enough power to hold airspeed in the climb phase /angle you have set in the cli) 5. Pick up the airplane, Do NOT run, just Face the wind take one step as you throw the WING level (never try to throw the fixed wing up steeply as auto-launch will disable itself at 45° tilt ; We always throw level or slightly up like approx 5° max) - approx 0.5 secs after you throw it the motor will spool up to the cli settings you save. 6. Pickup the Tx calmly within 10 secs and take over by moving the Elev/Ailerons/Thro. 7. Turn off Auto Launch. NOTE : Dummy Launch test in iNav - you can remove the Prop and do all steps above - just don't let go the WING after the throw "G" force - motor should spool up and run.
How do i know if my C of G is wrong on an RC fixed wing ? Answer = Always maiden with the C of G as per factory settings (or slightly forward of that - the Elevons should have Reflex = UP by around 4mm) - then gradually move the LiPo back - the test is when too far forwards - an ailerons-only roll (trim for level flight then do a 360° roll without touching/using Elevator) will result in a large corkscrew flight path ; as the C of G comes backward the spiral will flatten towards a straight line. Be aware that if the C of G crosses the rearward limit the plane/Wing will be uncontrollable - More info? C of G can also be calculated using eCalc.
How do i tune this new PIFF controller in iNav 1.6.0 ? Answer = the Fixed wing PIFF values are not shown in the UI PIDs page - not yet - atm they are so new they still exist only in the CLi page ; go to CLI and type "SET" return - you will now see fixed wing values with fw_ Tuning iNAV PIFF is covered HERE
How do i SAVE my iNAV settings after i made custom changes - What if i want to roll back to a setting from a few days ago? I want these as backups for later, or to send to a friend? Answer = This is called a "CLi dump". with your Sirius™ AIR3 connected by USB goto the CLi Tab ; at the bottom type dump , return ; the screen will fill with data ; Use your mouse to select all the text ; COPY it - Create a folder on your PC/Mac ; Open a blank TextEdit Doc (plain text doc) ; Paste all the data into the blank text .txt file - (delete the top line "entering cli mode...) ; save each file with a smart name to allow Roll-back. Later when you want to restore a Sirius AIR3 - goto the CLi TAB and paste all this "dump" text ; Return ; once it's finished scrolling down ; type SAVE - the AIR3 is now fully restored to the Roll-back data.
How do i see whats "Different" about my iNav settings ? Answer = in CLi TAB ; type diff or diff all Diff all can also be used to backup to a text file but be sure not to include the defaults line at the top, only the rest