AQ m4 Rx-problem ?

[Crizz]

After finishing my DeadCat 500 with AQ m4, i tested it at the backyard , found that KISS-ESC are crap for 4s after i spent lots of time for param-tuning, and after changing to 3s setup, i had a testing-hover for more than 60 sec. first time now.

And i had the first big problems that i couldnt figure :

After 3 min´s of flight, my copter suddenly came back and down on pitch / nick, i softly smashed it into the greenery, no damage. Tried it one more time and after around a minute , it did the same - but, with nick-forward. Okay, my Kiwi-tree caught it....

Have no clue what happened, but : i have MWCLight RGB installed at my copter, and this thing switches the RGB-LEDs that are attached to alternating red-green-blinking light if RC-signal is void - and it showed me a void RC-input for short term right before that happened ( both times).

In the first, i thought about a crosstalking problem. I placed a shield below switching BEC and rest of electronics, another one between the MWCLight ccontroller and frame, checked wiring and changed to twisted pair , but had no success : this afternoon, it happened again. First after r.a. 120 seconds of flighttime ( first "void rc-signal" on the LEDs"), landed, checked connectors, started again, same after 60 seconds.

Have to say that i´m using a FRSKY receiver TFRS8 with my Futaba T10. This Rx has CPPM output for Ch1-9 and PWM-out for Ch5 - 10 simoultaniously. At Ch 6 i connected the mentioned LED-Controller, so its PWM-driven.

Right before i started to write here, i checked again what could cause my problem, and found two items i could imagine :

1.) i connected my receiver to the m4, and at the documentation it is mentionened to use Radio2-define for external Rx and Radio1-define for internal CYRF-Rx. Mine was set up as PPM on Radio1 - could this take any effect ?
(changed it to Radio2=PPM and Radio1=None , will check tomorrow, all functions good at ground)

2.) the FRSKY-Receiver produces a PPM-Signal with lenght of 20 ms to transfer Ch1-9. I know that there are some electronics that have problems with it, but only a few. So i made thoughts where it could effect and found the PPM-scale value (set to 3 by default). I cannot find any real helpful informations about that hint, what is divided and where to set it on any problems, but could also imagine that there is a problem with the expecterd PPM-lenght, so i would need reference values to decide if my 20 ms length fits with the 3.0-scaler or if any change is need there.

thx in advance for your help !

[Max]

[Crizz]

Hi Max,

i already took my scope and checked the PWM of Ch5 to check if i have void signal at ground during longer opteration, but nothing to be found. I even tried with running motors on the ground, same game : 5 minutes of run without any noticeable problems. Okay, environmental conditions are different, so will give it a new try outside and insert sd-card to log data. Guess this will help better.

If problem still occurs during flight, i´m gonna go and swap receiver. Only bad thing : i need 8 channels ( 4 ch steering, 2 ch. flightmodes, 1 ch pattern select of MWCLight and 1 ch retracts ) and my other PPM-receiver only has 7 ch., but okay, for testing it will be good enough to do w/o retracts

FW update for the Rx isnt available yet, and if if would, i cannot used it because my Radio doesnt run under ETSI EN 300 328 V1.8.1 and after updating receivers fw, it needs a transmitter that runs same protocol.

About signal quality, i will check. Never watched for it before.

Only thing i found is that cpu is still at 51% duty while idle at ground - maybe because he cannot find GPS while indoor. ?

[Crizz]

Max, one question : how to reduce the number of used channels ? I found that in the listing of params channels up to nr. 11 are defined. Simply delete those entries ? I only use 0-7 (1-8 at receiver-side)

[Crizz]

checked with live telemetrie and found growing number of Rc-errors. Swaped Rx with a tiny Futaba RASST 7 ch and it works ( had a 4 minutes hover in the backyard w/o any fail ).

So it seems to be really a problem of the FRSKY-Rx like you mentioned, Max.

Have to see how to go ahead now. Not easy, seems its time for a new Radio

[Max]

[Max]

[Crizz]

yep, i can set the transmitter to 7-ch mode or 10 ch mode. But the mad thing is that the FRSKY doesnt work when transmitter is set to 7-ch mode instead aof 10 ch.

I´m gonna try the SImprop GigaScan series, sounds like a good alternative to Robbe / Futaba receivers and for affordable price. Will call the manufacturer tomorrow and check some details.