Hi All.....

Had a bit of an unusual event take place with one of my quads recently.  Was wondering if anyone else has had anything similar happen….

Equipment:
FC: X-Racer v3.1/w BetaFlight/X_RACERSPI 3.0.1 Oct 18 2016 / 10:40:35 (48b7b4f)
ESC’s: Flycolor Raptor BLS series 30A running Multishot
Motors: Emax 2205 2300kv
FC has the following firmware loaded: BetaFlight/X_RACERSPI 3.0.1 Oct 18 2016 / 10:40:35 (48b7b4f)
BLHeliSuite 16.514.8.0.0

Event:
Went out to fly this evening and when I plugged the quad in, it made some really weird beeps, not at all in the pattern it would normally do.  I unplugged and plugged it back and it went through it’s normal boot sequence, so I just assumed the first time was a fluke (wrong…. lesson……listen to what the machine is telling you). Anyway, when I went to take off, I pushed the throttle stick up, as soon as it clicked into the first ratchet, the thing took off like it was shot out of a cannon, full throttle.  The throttle was in a position when the props should have been idling.

So on the work bench it went (props off). Testing confirmed that as soon as the stick is moved it goes instantly to full throttle. Everything checked out with the flight controller/ESC’s/connections and settings in Betaflight.  Then I hooked up the BlHeli configurator and found that Max_Throttle was set BELOW the Min_Throttle.

The last time I few it there were no problem and no crashes (well nothing significant anyway)  I set everything back where it’s supposed to be and now it is working fine…..or so it would seem.

Has anyone else run into this?  My concern is that somehow this could happen again….for no apparent reason.
I am interested in hearing anyone’s thoughts on this…..thanks!!

It sounds like the ESCs somehow entered calibration mode and recorded an incorrect calibration. That was probably caused by pulling the power when they didn't make the usual startup tones.

After I set up any new ESCs, I turn off the "Programming by TX" option when I'm done so that I can't accidentally change anything.

(16-Aug-2017, 07:36 AM)unseen Wrote: It sounds like the ESCs somehow entered calibration mode and recorded an incorrect calibration. That was probably caused by pulling the power when they didn't make the usual startup tones.

After I set up any new ESCs, I turn off the "Programming by TX" option when I'm done so that I can't accidentally change anything.

Plausible explanation.  Doesn't explain why they didn't make the usual start up tones in the first place.  "Programming by TX" was already disabled for the reasons you stated. I don't know what would have happened if I had tried it after the unusual start up without unplugging it first.  I guess we'll see what happens this afternoon when I try it again.....

Did you have it on the bench, connected to BF right before that happened? If so, what were you working on?

(16-Aug-2017, 11:45 AM)sloscotty Wrote: Did you have it on the bench, connected to BF right before that happened?  If so, what were you working on?

Nope.....Haven't been "under the hood" in weeks and it's been flown many times since then....go figure.

For anyone that may still be following this thread, I just took the quad out and flew a pack out and it flew perfectly. Thats good I guess, but it bothers me that it may do the same thing again at any time....guess time will tell. Thanks unseen and Scotty for the responses.

It drives me crazy when a problem just miraculously fixes it self because yeah, it's always in the back of your mind that it could rear it's ugly head at any time. The fact that you stated that you hadn't popped the hood in a while and that it appeared that min and max throttle were reversed has me wondering if it was some kind of minor transmitter glitch...........

(17-Aug-2017, 03:12 AM)RENOV8R Wrote: It drives me crazy when a problem just miraculously fixes it self because yeah, it's always in the back of your mind that it could rear it's ugly head at any time.  The fact that you stated that you hadn't popped the hood in a while and that it appeared that min and max throttle were reversed has me wondering if it was some kind of minor transmitter glitch...........

Well, it isn't that the min and max throttles reversed......the min throttle was still where it had always been, but the max had moved to a position even lower then the min.....on all four ESC's and they were all identical.  I have programming with the TX disabled so I don't see how I could have accidently changed it through the TX.  If it's because of the TX I haven't been able to isolate it, but I'll keep that in mind.  Thanks RENOV8R!

Just another question: Is your receiver connected PPM or SBUS (or is it connected PWM)?

(17-Aug-2017, 02:03 PM)sloscotty Wrote: Just another question: Is your receiver connected PPM or SBUS (or is it connected PWM)?

Its an XSR using SBUS.

(17-Aug-2017, 02:08 PM)sirdude Wrote: Its an XSR using SBUS.

Well, my new possible theory may not hold water.  (I first thought of it thinking maybe you were using PWM.) 

But here it is anyway: my thinking is that maybe BF is not honoring the disabled "Program by Transmitter" setting in BLHeli.  But just in case the ESCs are not honoring it themselves, what might have happened (remember this is just a theory) is that you had your throttle stick just slightly advanced when you plugged in and the ESCs read it as entering calibration mode - then you bumped it down and it calibrated the new max throttle.  I seriously doubt that's it, but IF it IS, you can duplicate it.

First connect to BF and go to the receiver tab and move your throttle to 5 or 10 below min throttle.
Then disconnect, but leave your throttle stick where it is. Turn off your transmitter.
Then turn on your transmitter, plug in a battery and see if it happens again.

I can't think of anything else to try.

(17-Aug-2017, 03:45 PM)sloscotty Wrote: Well, my new possible theory may not hold water.  (I first thought of it thinking maybe you were using PWM.) 

But here it is anyway: my thinking is that maybe BF is not honoring the disabled "Program by Transmitter" setting in BLHeli.  But just in case the ESCs are not honoring it themselves, what might have happened (remember this is just a theory) is that you had your throttle stick just slightly advanced when you plugged in and the ESCs read it as entering calibration mode - then you bumped it down and it calibrated the new max throttle.  I seriously doubt that's it, but IF it IS, you can duplicate it.

First connect to BF and go to the receiver tab and move your throttle to 5 or 10 below min throttle.
Then disconnect, but leave your throttle stick where it is. Turn off your transmitter.
Then turn on your transmitter, plug in a battery and see if it happens again.

I can't think of anything else to try.

Interesting theory Scotty. I am tending to agree that that's not the problem.  My transmitter is calibrate pretty tightly.  In other words, I have motor stop enabled and when the stick is at the bottom of it's range (against the stop), the motors don't spin even when armed.  When I move the stick up....even slightly (first ratchet) they start spinning (takes advantage of all the resolution I can get).  So there is not a lot of "slop" there to play with.  I realize that electrically it could still happen.  I give your theory a try as soon as I have a chance (probably this weekend) and report back on what I find.  Thanks Scotty, much appreciated!

The "programming by TX" option has nothing to do with Betaflight. It's purely an ESC function and programming mode (or calibration mode) is initiated by the level of the throttle signal that the ESC sees when it powers up.

So, either it's enabled or it isn't.

What's even more disturbing about this is that all recent versions of BLHeli_S have a change that should refuse to store calibration values if there is less than 250 in difference between min and max values, so even if the ESC wasn't honouring the "programming by TX" setting, it should not have been able to set max throttle lower than min throttle.

The only thing I can think of is that there's some problem with the code the ESCs are currently flashed with. I'd suggest that you re-flash the ESCs with the latest BLHeli_S code using BLHeliSuite and not the Chrome app.

(17-Aug-2017, 04:59 PM)unseen Wrote: The "programming by TX" option has nothing to do with Betaflight. It's purely an ESC function and programming mode (or calibration mode) is initiated by the level of the throttle signal that the ESC sees when it powers up.

So, either it's enabled or it isn't.

What's even more disturbing about this is that all recent versions of BLHeli_S have a change that should refuse to store calibration values if there is less than 250 in difference between min and max values, so even if the ESC wasn't honouring the "programming by TX" setting, it should not have been able to set max throttle lower than min throttle.

The only thing I can think of is that there's some problem with the code the ESCs are currently flashed with. I'd suggest that you re-flash the ESCs with the latest BLHeli_S code using BLHeliSuite and not the Chrome app.

Actually I had been thinking along the same lines.  Scotties theory, although probably not the problem is easy to verify so I'll check that out first.  Additionally, I will reflash all the ESC's with the latest BlHeli-S code.......should probably be done anyway.  Thanks to both of you for your input, will update thread when I know something....or verify that I don't.....

(17-Aug-2017, 04:59 PM)unseen Wrote: I'd suggest that you re-flash the ESCs with the latest BLHeli_S code using BLHeliSuite and not the Chrome app.

Is something amiss with the Chrome app?