Home Forums Everything about the Mini Tricopter Reciver for F3FC + Spektrum DX8

This topic contains 31 replies, has 8 voices, and was last updated by  gcanfpv 11 months, 3 weeks ago.

Viewing 15 posts - 1 through 15 (of 32 total)
  • Author
    Posts
  • #29481

    mioh
    Participant

    Just watched the new Triflight Setup video and at 4:05 David say that the F3FC board does not support PPM RX input. Serial-based receiver is needed. I have been flying my tricopter with KK2.0 for about three years and have no clue what receiver I now can/should use, so I need some help.

    I have today a new cool Mini Tricopter with the great F3FC board, and an old Spectrum DX8 with AR8000 and TM1000. (Never used the TM1000)
    http://www.spektrumrc.com/Products/Default.aspx?ProdId=SPM8800

    I want to be able to fly the tricopter, but also if possible use some telemetry. So, what small, stable, cool receiver do you recommend?

    #29504

    swissfreek
    Participant

    Yes, you won’t be able to use your AR8000 with the F3FC as it is PWM, which is no longer supported. You still have a few options for Spektrum.

    1) use the Satellite module that came with the AR8000 by itself as a serial receiver on UART1 (make sure you set the board to only put 3.3v to UART1 as the Satellites take 3.3v. Also, in this case you bind the Satellite by attaching it to your AR8000 first and binding the AR8000 to your radio for your Tricopter model. There is no telemetry port on the Satellite.

    2) buy the Spektrum race receiver. This is like a Satellite but has longer antennae and I believe diversity, so you should get better reception. This has serial output like a Satellite. It’s not SBUS but it’s close enough in latency that it doesn’t matter. You can bind this directly from the receiver. You will not be able to use telemetry with this receiver. It is a little pricey at $50. I would recommend this for the most reliability and peace of mind.

    3) use an OrangeRX receiver. OrangeRX makes several receivers that are Spektrum compatible and has either SBUS or PPM output (in addition to PWM). If given a choice I’d go with SBUS versions, but that’s your choice. They are also well-priced, but you will probably have to get them from Hobbyking’s international warehouse, which means the shipping will cost as much as the receiver (but it will get to you fast and it’s still cheaper than a Spektrum receiver without shipping). I recommend that R620X as no matter which version you get they all support 12+ channels over SBUS, the only difference is the number of PWM pins, which you won’t use and just adds physical size to the receiver. These will allow you to use telemetry (and extra Satellites for diversity). I have not had many reliability issues with these and the price is nice. They are a little bulky due to their case, but I have taken them out of the case, desoldered the pins, and wired them into some pretty small quads and that has worked well. If you have to have telemetry this is basically your only choice.

    4) LemonRX also sells a PPM receiver that is Spektrum compatible. It is also decently priced. It will also ship from China and take a while (a week or two). It will not support telemetry modules. I have had several brownout issues with these and personally no longer trust them, but your mileage may vary. I don’t think I would recommend this option, but it does exist.

    I have used all of the above options except the new race receiver. I never used telemetry with any of my Spektrum gear due to price and the need to add extra modules. I own a DX8 and DX9 (which I lovelovelove). In the end, I switched to a Taranis so I could get easy access to SBUS and telemetry and add-on modules and so far I’m glad I did. The DX9 and DX8 sit on a shelf collecting dust, sadly.

    #29508

    swissfreek
    Participant

    Also, for reference I think @david made a “typo” in his video. He says “parallel PPM” and points to the PPM tab but I’m 99.9999% certain he meant “Parallel PWM”, which is where each channel has a wire. It’s semantic in your case since the AR8000 is a PWM-only receiver and therefore will definitely not work because there are no PWM pin-headers on the board to plug the wires in to. There is a PPM header, though, which is what makes me think this is a typo (and also, not supporting PPM would be pretty unusual, though I figure sooner or later everything will be serial, so SBUS or XBUS or Spektrum etc.).

    #29516

    wynnsquad
    Participant

    I just bought the Orange R720X to use with my new board. It’s a tiny bit bigger than the 620X mentioned above but if you happen to be in the U.S. then it is currently in stock at the hobbyking USA East warehouse. The rest are all out of stock

    #29521

    mioh
    Participant

    Thanks for your help. 🙂

    One Orange Rx R720X V2 SBUS ordered from Hobbyking EU.

    #30077

    mioh
    Participant

    Hello again.

    After about two weeks the Orange Rx R720X V2 finally arrived yesterday. Now I have a new receiver/telemetry/F3FC question.

    Viewing Davids excellent “Triflight Setup video” https://www.youtube.com/watch?v=3aIhaIMubdM (again) and at 4:40 I am supposed to set UART 2 to right telemetry system. FrSky, HoTT, SmartPort or LTM. Reading the Orange Rx R720X V2 instruction manual did not help. Rather the opposite. After reading the instruction manual over and over again, and doing some googling I’m start wondering if telemetry from the F3FC, thru the Orange Rx R720X V2, to my DX8 is possible.

    Right now I’m just feeling stupid. 🙁 How do I get the F3FC telemetry data to my old Spektrum DX8?

    #30086

    swissfreek
    Participant

    Telemetry to a Spektrum radio is not possible the way that David shows in the video. That is for FrSky telemetry. In order to get telemetry to Spektrum, you’d have to use a Spektrum telemetry module and plug that into your receiver. It would not interface with cleanflight.

    #30158

    mioh
    Participant

    Thanks swissfreek.

    I have to settle with total battery package voltage from the F3FC raw battery power connector to the RX telemetry then.

    (Finished soldering an hour ago and just done the Triflight setup. Then using the Motor tab in triflight and raising one bar at the time two motors are going the wrong direction, so some soldering has to be done to two ESC. And then disconnected from the Cleanflight and arming with the receiver one front motors spins immediately, and there is no reaction from the back motor what so ever. It does not spins at all. So I guess I have a lot troubleshooting/forum search to do.)

    #30170

    mioh
    Participant

    (Got all motors spinning! 🙂 Just turned off Oneshot125 in Cleanflight. Motors still start spinning then arming the board, so I have some adjustment left to do in Cleanflight I guess. That and resolder two ESC’s to change motor rotation.)

    #30179

    mioh
    Participant

    AIRBORNE! It flies like a dream! 🙂 Well, if the pilot could fly it properly it should…

    The receiver is to bulky (just like swissfreek said) so the battery can’t get enough room. Will try to remove the OrangeRX case and wrap it with some heat shrink. Have some work left to do before it is finished. Shrink the ESC’s tubes and stripe them down. Mount the video TX and add a gopro mount on top of the Mini Tricopter. Also have to do some reading what voltage the Tattu 1800 mAh accus should have max and minimum. Then set the alarm on the F3FC board and Spektrum DX8 telemetry. The total battery voltage seems to be working. Got a reading on the transmitter display. 🙂

    (After some reading it looks like Armed = motor spinning slow. Coming from KK2.0 this feels odd, but I guess I will get used to it.)

    #30181

    swissfreek
    Participant

    Fully charged voltage of all regular LiPo packs (not the HV packs) is 4.2v per cell. So if it’s a 3S pack, it will be 12.6v fully charged, and if it’s a 4S pack, fully charged voltage will be 16.8. As for discharge, the limit is a little up to you, but commonly people set alarms at 3.5v per cell or 3.7v per cell if you want to go easier on your packs. In honesty, though, if you ever get an OSD and start paying attention to the voltage as you fly, you’ll realize it’s not a very good measure of pack level (the voltage sags when you kick the throttle, it drops very fast initially and then flattens out, etc.). You’re much better off using the current sensor, and you want to set the limit at 80% of pack capacity (at most), so you should be thinking hard about landing once you hit 1400mAh consumed.

    Yes, these days, the motors spin when armed. Wasn’t as common back in the KK2 days, but now it’s practically a requirement if you intend to do any sort of acrobatics, as you will often kill your throttle, and if the motors don’t spin at idle you’ll tumble. If you don’t intend to do much acrobatics, it is a feature you can disable. In the setup tab in cleanflight configurator, you can enable MOTOR_STOP at the top right (or disable? however you want to think about it). That way when you are armed and at idle throttle, the motors will not stop spinning. Again, depending on your flying style, this could cause your copter to fall out of the sky.

    #30182

    swissfreek
    Participant

    Also, what I did to get my R620X into my Vendetta (much tighter space than the mini tricopter) was to take off the case, desolder the PWM pins, and solder new pins at a 90 degree angle for the SBUS pins so they stay nice and flat to the board. I took a picture of it, I’ll try to find it and post it in here. Instead of soldering new pins, you could just solder some wires with a servo connector at the end, and then plug that directly into the pin headers on the F3FC board. Then you shrink-wrap the thing and voila: nice flat compact receiver, and it still leaves your telemetry ports intact since you will actually be using them.

    #30183

    swissfreek
    Participant

    Found a picture. Like I said, you could solder wires instead of pins there, would probably be less of a pain. I would have gone that route as well except I needed pins there to connect it to the Vendetta.

    Oh, and you can’t really see it, but under those pins, before I soldered them in, I laid a bead of hot glue, and then scraped it with a credit card to get a nice thin layer across the unused pins, just to protect them from accidentally shorting on the three pins I was using. On my tricopters I don’t use the pin headers, I solder in wires for just the pins I’m using (since especially on the old Naze frame, there was a *ton* of unused pins if you were connecting via PPM), and then put a layer of hot glue on everything else so it doesn’t short out if something moves in a hard landing.

    Attachments:
    #30186

    mioh
    Participant

    Thank you so much for reply, info and picture! 🙂

    Got Tattu LiPo 4S 1800mAh and have been reading http://www.rchelicopterfun.com/rc-lipo-batteries.html . Since I got a charger (Bantam BC6DX-II) that only charges LiPo to 4,2 V/cell I guess that rchelicopterfun recommendation 4,15 V/cell is not for me.

    About voltage or current sensor I have (to my knowing) not a choice there either. (If I keep my Spektrum radio.) The F3FC board can start the beeper at 3,7 V/cell if I want to. And my DX8 can beep then battery pack reach 14,8V. To use the F3FC current sensor understand I need a new radio. If an OSD can show the current data from the F3FC that could be a solution in the future.

    Took of the case from the Orange receiver and tried it. Seems like I don’t have to re solder anything, just order some shrink tube. But if I do have to re solder I now know how to do it. 🙂

    #30187

    hertz
    Participant

    I wouldn’t bother with charging ordinary LiPos to 4.15, they’re an expendable resource like fuel anyways, you’ll have to change them occasionally and being a beginner gives plenty of room to kill the battery before it reaches 2000 cycles as the article states. These 0.05V may actually give noticeable flight time drops on better and modern batteries as they have pretty flat discharge curve.
    Minim OSD is indeed capable of displaying current draw and capacity consumed during flight.

Viewing 15 posts - 1 through 15 (of 32 total)

You must be logged in to reply to this topic.