Triflight setup guide

[lauka]

Here, no it also works when aux4 > 1500. (should work, didn’t test).

Attachments:

1. triflight_servo_TEST_NAZE_aux4.hex_.zip

[Terje]

I’ve updated the Arduino code to allow for a 2nd “servo” on D5. Starts as 1000us when button is LOW (not pressed) and changes to 2000us while the 1st servo is doing its 10 turns. Then changes back to 1000us. Originally it was to be used to arm the board 🙂

[Terje]

These are the test results:

(Running at about 5v)

Flip32+ controlled and powered BMS-210DMH: 376.5 degrees/sec
Flip32+ controlled and BEC powered BMS-210DMH: 391.8 degrees/sec
Arduino controlled and BEC powered BMS-210DMH: 408.5 degrees/sec

[EDIT] Uploaded the video

[lauka]

Okay I measured again with my Sony Xperia Z3 at 120 fps.
BMS-210DMH at 6V: 370 deg/s. Still a bit low compared to Terje’s 5V values.

For some reason the Mobius 60fps recording gives completely different values. This means only one thing, even more accurate yaw tail motor control! :).

[Terje]

@lauka the mobius might skip frames if there isn’t enough light.

If you are using a buck converter, consider replacing it with a proper BEC. Make sure the tilt mechanism can move freely. Make sure the cables are not binding.

[LeoTheHuman]

Terje, can you explain buck converter vs. BEC?

[Terje]

I can give you my definition 🙂

BEC

Buck converter

I noticed a voltage drop when using the buck converter type power supply and also noticed a fluctuation in voltage in general.

The BEC type seems rock solid.

On the other hand it is nearly impossible to find a 8v BEC type.

[GAntonjo]

We learn something new every day 😀

Wikipedia has the answer: Buck Converter. BEC is a little more generic term, as I see it. A BEC can theoretically be a buck converter, an other type of switch mode converter or a linear converter, but since it is “most common” with linear converters in RC BECs it is easy to generalize.

[LeoTheHuman]

Well, I’m not comfortable heartng up for 2w while providing 1w of power to my electronics, so I will keep using buck converters. I have no idea why should that give me a slower servo….

[Terje]

@LeoTheHuman you are confusing the BEC I linked to with the LM2940 based linear BEC built into the PDB frame?

You are more than welcome to reproduce my setup to do independent tests and publish them.

BTW your electronics and servo pull more than 200mw. – But please do test this your self 🙂

You are correct that running at 4S, with the linear BEC at its limit (1A), you waste 10w of heat to deliver 5w of power. Conservative flying would be half of that. – I’m just comparing a crappy buck converter to a slightly better switching BEC.

For those interested, RCModelreviews has a nice video on this.

[RCExplorer – David]

Terje: Get some LM2940-8, it’s the exact same BEC circuit that is on the PDB, but gives out 8V 🙂

[Terje]

@David will the Naze32 board run on 8v, or will I need a separate BEC for that anyway?

[LeoTheHuman]

Naze and most of the receivers should work with 8v. Be careful with higher voltage, though. Although Naze32 (latest versions of rev5) should be able to work off 4S battery directly, most of receivers require lower voltage. For example, D4R-II is spec’ed for up to 10V.

Well, I’m not confusing BEC with anything, BEC is a general name for all the voltage regulators used in RC. Most separate BECs are just buck converters anyway.

[chilternflyer]

Hi guys.
I’ve had my dozen flights with Triflight (0.3) and it is awesome! (well done Lauka ;-)) I just love the way it turns.
However I have a slight problem using the Luxfloat PID controller.

I’ve never got on with Luxfloat because I fly in angle mode (I’m too scared of flipping it at low level) and Luxfloat is pants in angle mode (huge amount of latency on the sticks).

So now I find that I’m having to learn to fly in horizon mode and it scares the *** of me. I’ve got it tuned so that the auto-level kicks in OK so I shouldn’t crash but the scary part is that I keep tipping it over.

So here are my questions:-
(1) Is there a way of limiting the max angle? (E.G. 60 degrees) in horizon mode. I’ve tried altering the horizon transition (LEVEL D term) to 100 but it will still do rolls and flips.
(2) Plan B: What do you have change in Luxfloat to get it to respond quicker in angle mode? (The latency is so high that it’s like flying a big fixed wing!) Other (MWC) based PID controllers work fine in angle mode so what’s with Luxfloat?

[LeoTheHuman]

Do you use the stock triflight 0.3 PID settings, rates and expo curve? If so, you might just want to give it less rates if you don’t want it to flip on the spot in horizon mode. Fairly speaking, I didn’t notice the tendency to flip easily in the mini, but it is tuned quite aggressively to do so.

[Author]

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