Bix3 setup for FPV and APM

This is a stock Bix3 running a R615X receiver, along with Hobbyking's 250mw FPV starter kit. Also included in the electronics package is an APM clone running Ardupilot. A Ublox NEO-6M GPS+HMC5883L Compass module, a mimimOSD clone, and a HC06 bluetooth module

[@aerofpv2109]

Such a great popular FPV platform. This is such a superb well detailed video. Thank you Sir.

[@jmhrvy1947]

+Aero FPV Appreciate the kind words.. I wish I had had a better camera for shooting in such tight quarters.

[@aerofpv2109]

Regardless you did a swell job Sir. Really clear and detailed. This will help many viewers.

[@j3fron]

well, i would insulate the gps cable mate. reason? simple, too close with RX i would mount GPS module in outside, mount gps under wing will blocked GPS sats, you'll need more time to receive sats lock

[@MathieuTerzian]

Thank you so much for this video. What battery do you use? Considering setting up a Bix3 with FPV and AUAV-X2 (smaller pixhawk) with GPS and telemetry module. And an action cam (probably RunCam HD2) That's a lot to fit in/on the plane ;-) Was wondering if 3S battery is enough. Thanks for your help.

[@einsaan]

Thanks for all your work on putting up this video. I am planning to setup Cyclops Storm OSD with a 600mw video tx and 5v 700tvl camera. This video was very useful in planning out my setup. What was your flying weight with the setup?

[@jmhrvy1947]

Thank You, and GL with your project

[@jmhrvy1947]

That's a good question. But I honestly don't know. The plane, as shown in video, balanced perfectly nose to tale. And when the plane had been first flown (without any of the extra electronics) I found I had add ballast (in the form of nuts and bolts) to achieve the same balance. The electronics weight was less than the original ballast. So I was confident the plane would fly with this payload. So I never bothered to check its "all up" weight. Your setup sounds like a nice one, and with a 600 mw video link I'm thinking you're looking at longer runs than what I typically fly, so I understand your interest weight. FWIW: My flights are in the 10 minute and under a 1/4 mile range.

[@husky041]

Thanks for this. I'm building a Bix 3 and also plan to use an APM (maybe the mini version) with MinimOSD. Interesting place to mount your gps antenna. I may copy your setup, or I might mount it on the tail boom. Probably a silly question, but doesn't it have any problems seeing the satellites with it being hidden under the wing? And doesn't the APM have to be perfectly horizontal? I have an APM too and was puzzling over how to be sure it's horizontal in the fuse.

[@jmhrvy1947]

+husky041 Good questions. First, the GPS Satellite signals have no problem at all penetrating the foam and thin plastic found in the wing. As for the floor that APM sits on, turns out it's parallel to the plane's line of flight. In fact if you watch some of the later flight videos made with this set up, you can see that OSD's artificial horizon lies almost on top of the true horizon. Of course that's also due in part to the camera's angle relative to the line of flight. Bottom line, I had no problems with the APM flying the Bix with it mounted as shown here. And also on a stock Bix, this setup requires no additional ballast to get the CG correct. The one thing I did have to do is flip the APM's fore & aft settings. Because as you see it in this plane, the APM is riding backwards relative to its default settings. You can confirm that you have it correctly configured by observing that the plane's control surfaces move in the right direction to bring it back to level, when you point the plane's nose high or low, or tilt it left or right. Good Luck with your project, I think you are going to find its fun craft cruise the skies with.

[@husky041]

+jmhrvy1947 Thanks again, that's a big help. Can I ask if your MinimOSD is version 1.1? There are reports of some of their voltage controllers overheating, taking out the whole board. Painless360 did a video about this and how to fix it but wiring is a hassle. However I've also heard that the problem has been fixed. I'll probably risk it! Cheers.

[@jmhrvy1947]

+husky041 Mine was the newer version, and while it ran warm (the video chip) I didn't have any issues with it overheating. I did run into a problem with it not syncing to camera that I first flew with. I ended up making some small changes to how the sketch initialized the chip, which for me cured the problem. I posted my findings to their web site (code.google.com/p/minimosd-extra/) see defect 115. Don't know if these changes have been incorporated or not. I also found that the code would not recognize (display) when you were running APM in the Learning mode, and revised the sketch (OSD extra) for that as well. The only other issue found with setup shown, was at certain distances (and plane attitudes) the received video would blank or flash. I solved this by using a different video channel.

[@husky041]

+jmhrvy1947 Thanks :-)

[@austntexan]

Was wondering about how you have your apm mounted. The surface on the bottom of the Bix3 is at a slight incline. Did you correct for this by leveling the surface with your foam board mount, or are you able to 'zero' the apm out once mounted, even on a slightly inclined surface?

[@farmfunuk]

Thanks, I have just setup a Bix3 for FPV and took some advice from this. Although my GPS is at the back as I wanted to move more weight rearwards Can I ask a couple of questions though. I mounted my Pixhawk the same place as you mounted your APM, on that ledge , however perhaps the angle on my version of Bix3 came out different I am not convinced it is 100% level on the centerline. On mine the plane looks pitched up about 5 degs for Arduplane to call it level. However I am not a expert flier so I could be mistaken. Can you help me pick a reference line for getting the plane level. I need it to be right as I intend to fly slow for gliding as long as possible so don't want Arduplane pitching me up and risk stalling. Also I am getting my servos twitching, not caused by interference but by Arduplane inputs according to the Servo output graph. Pitch is doing it the worst, Rudder not at all, Ailerons a bit, I am thinking this is caused by the Pitch/yaw/roll controller tuning not being spot on, when under zero or very low throttle there isn't much twitching, but if I push throttle hard (on ground without prop) it seems like its fighting itself to pick the right servo sweet spot.. could you share your settings? I have just used HXT900 servos.

[@jmhrvy1947]

+farmfunuk I "calibrated" my apm using a "level" table, and then installed it on the "deck" of the plane (as shown in the video). I found that that proved to be the right way to go. Because when the plane was in the air, under apm control, it flew with the same attitude as what I had for the manually trimmed setup. So I don't think you'll need to worry about that. I don't know what kind of payload you have in the nose of your plane, but with the configuration shown, in the video, I didn't have to add any ballast either to the nose or the tail. Curiously, I did have to add a weight to one wing tip to get it to balance left to right (go figure). I don't know what to tell you about the servo twitching. Using the APM unit shown, I didn't really notice that effect. However, the surfaces should move (when you're in a "stabilized" mode) to bring it back to level. If yours do do that , and the "twitching" isn't overly so, then I don't thing I'd worry about it. Also if you haven't already done it, you might want to look at my other video, that focuses on "Tuning" the Bix.. Basically I just started with the generic settings and let the "tuning mode" do the work. Like you, I just wanted to cruise around, and watch the world go by... I found this plane to be the perfect platform to do just that... I hope that you will enjoy yours as much as I have mine.. One word of caution though, don't let trees, and the like, get between you and your plane

[@farmfunuk]

+jmhrvy1947 thx, I did calibrate like that also, but I think its possible there are slight variations in the mold , the ledge might be at same angle in mine. I had to buy a second bix3 after a crash, before I was using Ardupilot and there are slight variations in some things, for example my canopy didn't fit the new one which was a fraction smaller. So I would still like to get an idea of what angle other people are flying at, I will test myself but as said I am not the expert. I think basically the pitch yours in resting at on the table at the start of the video looks about right. For mine it shows level when its resting on the ground with the wheels on, nose clearly pitched slightly up. I definitely think my servos are oscillating, but this is the first Arduplane I have setup so I am not sure is its within acceptable limits or not, I don't like it though I think the servo could be damaged if its going on over a length of time. (I have used Arducopter before) Maybe I'll make a video of it. I was just curious if it was normal or not. Basically just have it on ground, with in FBWA armed and motor on, if I then throttle up a reasonable amount the pitch servo has a lot of movement back and forth as if its struggling to find the right position. Servo isn't broken, it works in manual.

[@jmhrvy1947]

+farmfunuk The way you describe it, it does sound abnormal... Remember I haven't seen your set up so what I say next may not be at all relevant. But the first three things that come to mind that might produce the symptoms you're describing is 1. maybe there's a problem with the MPU & its sending the APM false motion signals, or 2. is the APM/MPU secured well to the deck? (in my set up the 3M foam block and the foam board cradle lock the APM into position.) And finally a 3rd possibility is the PID settings may be too high (As I said, on mine, I started with the generic settings and let the tuning do the work. Initially when I'd go from manual flight mode to FBWA, the plane was extremely sluggish, and couple of times on the early flights I almost crashed because it was so slow to respond, but with repeated passes it became much more responsive, However in FBWA its never been as quick, as when I'm in the manual mode. Another question, were the servos twitching like they are now, on your original plane? And yes, if you make a video of what's going on, that would be very helpful. Let me know when you do

[@farmfunuk]

+jmhrvy1947 No the servos don't twitch in manual mode, nor in FBWA on no or very low throttle. But when I raise the throttle up the pitch servo in particular starts to oscillate. Could you let me know your PID's? at the moment I took the values from Arduplane that correspond with Bix2 as they didn't have a Bix3. But even so maybe I have my linkages set too far down the arm, maybe its better, less stress to have them shortened a bit. Oh, something else I was going to ask you. how do you connect to the APM with it glued in place? I was intending to use wireless telemetry to download logs, but apparently support for that is being discontinued as its too much data. Guess you are using the bluetooth for that? or were you able to get a usb connector in place?

[@jmhrvy1947]

+farmfunuk " how do you connect to the APM...bluetooth...?" Exactly Here are the PID and other basic settings.. They are fine for the type of flying & conditions I fly in However I only have one flight venue, so don't know how important this will be, but for record, "takeoff/touch down" for me is at ~1500ft above sea level. Servo Roll Pid P = 0.721 I = 0.060 D = 0.054 INT-MAX = 20.0 Servo Pitch PID P = 0.563 I = 0.047 D = 0.042 INT_MAX = 20.0 Servo YAW Yaw 2 Roll = 1.0 Intergral 0.000 Damping = 0.000 Integrator Max = 15.0 L1Control-TurnControl Period = 18.0 Damping = 0.750 TECS Climb Max(m/s) = 5.0 Sink (m/s) = 2.0 Sink Max (m/s) = 5.0 Pitch Damping = 0.00 Time Const = 5.0 Other Mix's Pto T= 0 Rudder Mix = 0.500 Throttle 0-100% Cruise = 45.0 Min = 0.000 Max = 75.0 SlewRate = 100.0 Navigation Angles Bank Max = 45.0 Pitch Max = 20.0 Pitch Min = -25.0 Airspeed m/s cruise = 12.0 FBW min = 9.0 FBW max = 22.0 Ratio = 1.994 Hope this is some help to you

[@youniles]

did you have to mod the apm so it works with only one wire cppm??? or is there a setting in the apm you change for cppm?

[@jmhrvy1947]

+Youniles That's a good question. The short answer is no you don't need to modify APM (like cutting traces or soldering) to use cppm, but there are some configuration things you will need to pay attention to. This link ( planner.ardupilot.com/wiki/common-connecting-the-radio-receiver-apm2/ ) shows how to connect the CPPM output from the receiver to the APM . In this video (Bix3 setup for FPV & APM) I'm using an r615x receiver. It comes ready to send cppm. So no modification was required on that end. If you want additional information, about this receiver and different RC signaling formats, this link ( kzbin.info/www/bejne/fZO4fnZunZeonrc ) maybe useful [about the 4:50 mark, it addresses cppm] If I have missed the point here, let me know.