[bhuism]

Thanks guys, I think I get it now. I also see why only these pins are eligible for ADC2 work in the f3 datasheet. I can’t just use the resource command to set PWM1 (PA6) to NONE, and move PWM1 to PPM (PB7)?.

I didn’t think it would be this much work to get feedbackwire working, since there are no free ADC2 pins left. Maybe I’ll try removing the components which screw up the normal feedbackwire working on the RSSI pin on the bff3, and find out where I can solder the PB2 pin.

[bhuism]

@jihlein, I’ll try to create a PR for BFF3 when I get it working, thanks!

[bhuism]

Ok, I’m out of options in getting the servo feedback wire working on bff3. Custom bff3 firmware’s with (target.c):

#define EXTERNAL1_ADC_PIN PA8 (let strip)
or
#define EXTERNAL1_ADC_PIN PB7 (ppm)

and

set tri_servo_feedback = EXT1

did not work.

Wat happens is, the servo speed calibration throws the servo one time full deflection then centers and stops (not a couple of throws as normal). The voltages I measure on the feedbackpin are correct, pulse 1086 = 1.021v (min deflection) and pulse 1973 = 2.460v (max defection).

I guess there needs to be more software configuration in order for these pins to be readable by the tailtune logic?

[bhuism]

If it’s possible that the servo feedback wire can be ‘resource mapped’ to any pin, with the new fancy resource mapping system of BF3 that would be great.
Since there are free pins on the bff3 board, pin A03 for instance.

Attachments:

1. 

   Mh41SmG.jpg
   

[bhuism]

@lkaino, I’m afraid the rssi pad of the bff3 can not be used, I’ve read here that it is not a clean input pin, but has some ‘inverter volt-clipper’ circuitry. Also, when I connect the feedbackwire to this rssi pin the servo is not working anymore and always is in de min position, despite whats it commanded to do. I’ll try to find another pin, EXT1 was only for naze32 boards as you said. Current ADC is hard wired, and RSSI is not working. Maybe I can patch triflight so that EXT1 can be used on a bff3, or do you have a better idea to get the feedback wire connected on bff3?

[bhuism]

Ha, good find, I didn’t even see the rssi pad. Now I have to put in the feedback wire 🙂 Then I think the bff3 should perform as good as a rcf3.

[bhuism]

Mathematically I think this is pretty difficult to do reliably? When the yaw controller needs motor power to correct a yaw error, it will by definition apply a pith and roll force, shouldn’t the controller not negate this unwanted pitch+roll force with a counter force? should be doable I think.
A bit the same as yawing on a quad and keeping it from going up or down. Sorry for trying to go into details I don’t fully understand. triflight on bff3 is better than bf on a bff3 🙂

[bhuism]

a, ok.

Here the promised logs. Baby tri with triflight 7b1 on a betaflightf3 board, no tailtune or connected servofeedbackwire. I did set servo min middle and max.

Just LOS flying with a few rolls and punch out, no forward flights. Sync video with log with +28.6 seconds.

I find that the tail servo twitches much more in triflight 0.7 beta, in with BF 3.7.1. I might try the servo lowpass.
The rolls stop beautifully, long live d term. Also the yaw authority without throttle is better than with BF.

log: http://eleanor.odee.net/public/20170426/LOG00001.BFL

mov: http://eleanor.odee.net/public/20170426/20440001.MOV

If there is anything else I can do testing triflight on betaflightf3 board let me know.

[bhuism]

Lets see if I can follow your thread of thought here. When the tail motor spins up, creates force, and it’s at 45 degrees for instance, it will create a yaw, pith and roll force. Wich must be compensated? or not? Am I correct in assuming that the PID controllers for pitch en roll are not changed at all? and because there is no stick input for these pitch en roll controllers, they will compensate automatically? or do we need some logic?

I will do some yaw spins today with a blackbox log with a betaflightf3.

ps: why not put the allready made fix for this in, if it works? to kill the roll I term when yaw input is given I mean.

[bhuism]

> I’m guessing that the RCEXPLORER3 image is the right one for The “F3FC” integrated-into-the-frame FC from the RCExplorer store?

@larrytru Correct!

Another thing:

I will try the babycopter tonight with triflight 0.7beta1 on a betaflightf3. Per request, I will post the bblog.

I would love to know which pin the “EXT1” value of cli setting “servo feedback wire” translates to on a betaflightf3. Should the servo feedback wire setting not be integrate in the new cool “resource” mapping stuff of betaflight?

last question, when is the servo feedback wire exactly used? only during the servo speed test/tailtune? or also during regular flight?

B.

[bhuism]

lkaino wrote:

> @bhuism: I could take a look. Do the Aikon ESCs support dshot?

@lkaino,

If you still can look at the DMA/Channel mapping (seems to be the issue) for dshot would be great, I don’t get the ST datasheet on this subject. I stopped at the i8051 architecture 🙂

Here it says that a PPM pin could be a dshot capable pin, to me this does not seem to be the case with a F3FC.

The maximum number of motors on dshot is 2, with this resource mapping:

resource MOTOR 1 A08 (official motor 1 pin)
resource MOTOR 2 B08 (led strip pin, official pin a07 does not work)
resource MOTOR 3 A01 <– not working (official pin b00 does not work)

maybe thats a start?

[bhuism]

Did anybody got betaflight+dshot working on our f3fc? I tried every combination of pins (ie pwm5, pwm6, ppm) I can only get motor 1 reliably to work with dshot.

@david can you make the schematics public? or can I receive them?

maybe I can figure it out then,

Bas

[bhuism]

As per https://github.com/cleanflight/cleanflight/blob/master/docs/Board%20-%20F3FC%20Racing.md the servo feedback is on PA6, if that is what you are looking for.

[bhuism]

Hi 2 all, @lauka would you consider enabling dshot in betaflight (and later triflight?) it is allready enabled for the LUX_RACE target, maybe it’s easy. I would have done it myself if I understand the hardware.

cheers,

Bas

[bhuism]

Also on the tri v4 with F3FC 0 problems anymore, log + video + dump downloadable here:

http://eleanor.odee.net/public/2016-07-25/

+6 seconds to sync.

It’s a LOS flight. Motor 3 fails heavily (desync?) around 1:11. WIl try different motor timing/demag compensation settings to fix that later. Tuning tips are welcome, since I am a beginner at tuning with BB.

frame: RcCxplorer tri v4
rc: F3FC
motors: T-motors 2212 1100kv
props: Graupner 9″ E-prop
escs: DYS BL30A Mini 30A with latest BlHeli
receiver: FrSky X4R-SB

thanks Lauka, it flies awesome!

Attachments:

1. dump-1.txt

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