• Finally are they working together?

  • My brother and I started, a small company focused on helping people get the best transmitter for your money. Although we're biased, we strongly believe the 9x transmitter is fantastic for UAVs, airplanes, quads, sailplanes and helis. It's what we use (along with all of our friends and customers).

    It's the open source firmware that is the key. The teams behind er9x, Gruvin and Open9x enable the 9x to compete with transmitters that cost $500 or more.

    For anyone in the market for a new radio...

    We stock the FS-TH9x (9B) transmitter as well as a 9x Upgrade Kit that includes the latest SmartieParts rev 2.2 solder less programmer, a backlight, upgraded thumb sticks, shrink tube to color code your switches and a neck strap. The upgrade kit makes modding your 9x really easy. The only tool required is a phillips screw driver.

    Additionally, for 9x owners who want to add better range, failsafe and telemetry, we stock the FrSKY 2.4ghz TX module and associated receivers. The TX module plugs into the JR-style socket on the back of your 9x. It's plug-and-play. No additional configuration is required (and it works with the factory or open source firmware).

    Checks us out at We're available for any questions (regardless if you buy from us or not).

    Good luck building your UAV!


    ParkeFlyer RC - Home
    ParkeFlyer - Home of FrSky, FS-TH9x, Turnigy9x and the Flyer9x 2.4ghx 9 channel computer controlled radio transmitter (based on er9x) for radio contr…
  • Distributor

    You might want to consider something like the WFT 7 channel radio, it is quite cheap, but is still a great radio!

  • Joining this late, but what's the point of arguing the legalities of not having failsafe?  I think that we'd all like to have failsafe as an option for the APM.  Why don't we figure out what the technical obstacles are and work to add this feature to the AC and AP code?

  • @Vernon - I suspect PPM_Encoder.h is the latest code used both for APM2 and later APM1, judging by the comments at the start.

    I agree that if you want to start discussing Failsafe options, another Discussion should be created - it's gone way beyond relevance for the current one.

  • @ R.L.  I don't think you really want me posting all the case law where someone has been sued into the ground for disabling/defeating a safety feature or starting a dangerous machine with no way to stop it.  Starting any machine without a reliable way to stop it is, in almost every case I can think of, generally considered reckless behavior.  

       There's a reason industrial machinery has large kill switch buttons in reach of the operator, lawn mowers stop when you release the handle, riding mowers stop when your ass comes off the seat, jetskis and boat motors have a kill pin you attach to a cord going to your lifejacket, cars stop when you let off the gas or turn off the ignition, centrifuges stop when you open the lid, etc., etc..  Most people don't like these features, manufacturers don't like the extra cost, and people often defeat them.  But they're their because courts have generally ruled that letting something out of your control with no way to stop it is reckless.  Most people consider it "common sense" and therefore juries and judges usually have no sympathy for people that don't make a reasonable attempt to implement something like this.  It is the difference between an "accident" and "recklessness".

       In the past you could probably get away with some things due to technological limitations as long as you took plenty of other safety precautions that are/were common in the field of RC.  Planes used to be loud (provides warning) and flown in remote locations.  Now you have no technical limitations, people like flying in parks and back yards, and the equipment is much quieter and flown in a manner where many of the people in the area may have no idea what is going on.

       You also have to remember that we have inserted a device which defeats the 9X safety feature of dropping the throttle signal on reception loss.  This isn't a passive, unknowable, or unpreventable thing.  That really limits your defenses.  You have to remember the opposing lawyer is going to be out for blood.  He'll pound the table and holler about how your actions caused the accident, you were reckless, you intentionally defeated a safety feature, on and on.  It gets really nasty sometimes.  Or they'll act so nice, pleasant, and reasonable the jury can't resist their argument, all while making you seem like Hitler to them.  They'll pretend like they're actually finding stuff out during testimony and are shocked by it, etc..

       I can tell you from experience that technological limitations are laughed at nowadays.  The judge just may pull out his cell phone and tell you that for less than $100 you can purchase more computing power than they used during the moon landing.  I was sternly admonished in court when I asked for a continuance because the court audio was provided on cassette tapes and I didn't have a working tape player (tapes were already archaic at the time).  The judge told me anybody can go buy a tape player for $10 at almost any store. (got my continuance anyways)

    Anyhow, I think we have made it through the stages of denial, anger, and bargaining.  Hopefully most of us are at the depression or acceptance stage by now.

    Vernon came up with great instructions on flashing the PPM, so it's time to get cracking on a solution.  Essentially we need to emulate standard safety features.  If control is lost (in lieu of a better solution) the throttle needs to be killed. 

  • You cannot have a craft crash under power.  If you have a system you know does this it is "reckless endangerment" to operate it.  If all else fails you HAVE TO PULL THE PLUG!

    In the issue we're dealing with ALL control is lost.  In that situation your only option is to pull the plug.  To do anything else is simply reckless.  You just can't legally risk people and property to try and save your gear.  

    If you had some better option it that would be great.  But if you loose control you must still always have a kill switch or "deadman" type switch.  It's very simple to implement.  Anyone can understand that if you are getting no signal you should not be holding the throttle on.

    If control of the craft is lost it MUST be shut down.  To legally operate the APM it must always:

    #1 cut throttle when it's not getting throttle signal (in the absence of any better auto pilot control method kicking in).

    #2 cut throttle when any lockup or freeze of the system occurs.

    The long and short of this is that it must have a deadman type kill switch that operates in all circumstances.  I write this because I have seen enough liability lawsuits to know exactly how this will go in court.  The prosecution will come up with dozens of examples where this is considered a basic safety feature (lawnmowers, etc., etc.) and they will have a programmer testify that they could do it in 10 minutes with a line or two of code with a watchdog timer.  They will then present evidence that this is a known bug/design flaw (this and the other threads here) and that nobody made any effort to mitigate the danger.  They will say it was reckless to operate a craft without this most basic, and easily understandable, safety feature.  It's just the same as the Toyota brake failure issue or a lawn mower that didn't shut down when the handle is released.  Lot's of people don't like these sort of safety features or disable them, but defeating them or not having them exposes you to tremendous legal liability.

    Believe me, this is how it would go down and they would quite easily get a large judgement against both the pilot and 3DR.  There are lot's of ways to mitigate both the danger and the liability, but ignoring it or pretending it's not a bug is not one of them.  You'll hear "So you KNEW about this bug/design flaw/possibility/danger," so many times you'll be sick of it by the end.

    I bother to type these posts because I want to see the hobby do well with minimal regulation.  I'm also now unfortunately placed in a position where I am very wary of operating my APM knowing that it could easily be painted as reckless endangerment.  

    If my plane were to crash under power, and I knew this could happen, and I did nothing to prevent it, and I operated the craft anyways, and it killed someone... I'd be guilty of manslaughter and facing 5+ years in prison.  That's the simple way of looking at it and it's easy to ignore this remote possibility.  But even if NOBODY gets hurt it's still reckless endangerment just for risking it.

    If I pull the plug and it crashes unpowered that is taking reasonable precautions to mitigate the danger.  A reasonable person would assume that a styrofoam plane, traveling at a relatively low speed, with a relatively low weight, unpowered, with reasonable safety features shouldn't be expected to kill someone.  Even if someone was killed I'd face little or no criminal prosecution for it.

  • Guys, just to bring a little perspective here, since I think some of you are new to the hobby.  I've been doing this for 20 years.

    Loss of signal has ALWAYS been a problem for R/C models. Back in the 72MHz days, the Rx didn't even know the signal was gone.  Depending on the weather on any given day, it could result in the Rx outputting something non-deterministic, or in most cases, all the servos would freeze in their last position.  In almost all-cases, this resulted in the model running away with throttle applied.  This was a common occurrence, and it's why responsible modellers did a range check every day.

    Now, with the advent of 2.4GHz and digital Rx, we had the opportunity for the Rx to actually recognize a signal loss, and attempt to do something useful.  

    But what should we do?  What is the one thing that every model should do on signal loss?

    It's undefined.  Every model is different.  You could drop the throttle signal low to shut off the power.  But in the case of a gas powered model, which direction is "off"?  The throttle servo could be reversed due to mechanical setup.

    In the case of the throttle channel, or really any channel, is the better choice to force a crash?  In my mind, forcing a crash increases the odds of injury for the simple reason that in my experience, a good number of signal loss scenarios can actually be corrected if you have a little time.  And staying in the air buys you that time.  Forcing a crash increases the odds of hitting somebody, because simply stated, it increases the odds of a crash.

    This is a really philosophical question.

    I think this is why the Turnigy Rx does what it does.  Dropping the signal output will result in result in most servos staying in their last position, and that includes gas engine throttle servos.  In the case of ESC's, I'd expect they would stop the motor.  It's just one of many options, and it's the one they chose.  Some Rx will hold all channels at their last known position.  It may be better in some cases, but not others.

    The best option is obviously a fully programmable Rx, so the user can program it to do what they want.

    In the case of the APM, all the same questions apply.  Is it better to force a crash?  Or is it better to buy time and hope the signal comes back?  Or is it better to Loiter until the batteries die (maybe loitering over that daycare facility)  (And BTW, many old-school RCer's would ask you WTF you're doing flying anywhere near a daycare facility or school).  Or should it RTL, maybe where people are standing?  What if there is a tree, house or daycare facility between it's current location and the LZ?  

    The system is currently not smart enough to make decisions.  And in the lack of the intelligent decision making, sometimes "do nothing" is the best answer.

  • Distributor

    Well guys I saw this thread a bit late but here is my comments on the Turnigy 9X thing. 

    oh before someone points it out again, yes I am a distributor and I sell these things so if you want to discard my comment fine with me... :) 

    The 9X is really entry level and you cannot fly far away without risking losing your expensive equipment (unless changing the TX/RX package) but even so I found that the screws will rust and stick will start to need adjustment now and then.

     A lot of people are not interested in putting a lot of money on TX systems because brand names are very expensive ($499 and up) 

    When someone new starts exploring the world of multirotors there is many decision to make and quite often the radio is an "easy" one to do.  Most that are on a budget and not thinking going pro level or carry expensive equipment will opt for the 9X (and associated family)  

    the FRSKY modules are really a great addition to get more reliability and you get telemetry (basic voltage built in) 

    But there was a need to an intermediate product and now we have it... We are using the WFlY09, a robust and well built radio (quality controlled and really way better once you compare the inside with the 9X) 

    combined with the FrSKY modules, this is very interesting for a nice price point. (with taxes and shipping it's around $400)   In my mind, having tried the big guns Futaba, Spektrum, Hitec this combo is a killer for the price.  You even get fancy side switches to control camera gimbals. 

    Again, yes I sell these but believe me when I say that I've put months into sourcing the best for the price Radio.  

    Check it out here:

    People around Mississauga you are welcome to drop by and give it a try... I know it's hard to buy these with only seeing pictures... 

    So in the end... should you buy a 9X ?  If you put in the FrSKY and keep inspecting the switches and sticks YES! it will be a great combo. Plus you can flash the firmware and install backlight and more.  

    Or you can get this pro grade WFLY09 with FrSKY modules and not have to open it up to solder things!  

    And if you truly have money you go Hitec Aurora but be prepared to spend more for almost the same thing. 

    Hope it helps! 


  • I've done some further investigation.  Turns out I was looking at old code the other day :-o

    According to the doco for the current PPM code :

    Failsafe mode

    If a receiver servo channel is lost, the last know channel position is used.
    If all contact with the receiver is lost, an internal failsafe is trigged after 250ms.

    Default failsafe values are :

    Throttle channel low (channel 3 = 900 us)

    Mode Channel set to flight mode 4 (channel 5 = 1555 us)

    All other channels set to midstick (1500 us)

    So it will Failsafe on loss of all signals, but loss of just Throttle could be disastrous.

    Turning to the standard Turnigy receiver, I did some more testing and it turns out that, on loss of the Tx signal, not all of the PWM channels disappear.  For some reason that I cannot fathom, Channels 4 and 5 continue to hold their previous settings.  This happens on both receivers I have.  So, the APM would not trigger a Failsafe, but continue on as it was.

    So, time to rip out the Turnigy stuff and install the Frsky modules.

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