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FETtec / Firmware

FETtec ESC Firmware repository
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Bidirectional DSHOT #3

Open bkleiner opened 4 years ago

bkleiner commented 4 years ago

Hi, Is there a chance that bidirectional dshot will be supported eventually? Really like the hardware so far :+1:

IB1387 commented 4 years ago

Bump. The only thing missing from this is support for RPM filtering. :-)

speurhond commented 4 years ago

RPM filtering would be great

wuzle commented 4 years ago

I agree. It would not have to be bidirectional DShot though, it could also be implemented into Betaflight. While I don't have any clue on how much work it actually is to make Betaflight OneWire compatible, in my opinion the update speed should be enough to provide a 8kHz PID-Loop with sufficient RPM-data.

In general I have not flown an ESC that so finely controls motors like the Fettec 35A. It really makes a big difference on tight lines and difficult tracks. This weekend I had the chance to directly compare two identical setups (one Singularitum with a Fettec35A V1.0 and another with that 20x20 Hobbywing BLHeli32) on our training track and the difference is quite stunning. The Fettec runs way smoother all around and provides way more control especially on the lower side of the throttle curve and upps the efficiency quite a bit. The only thing missing is the RPM-Filter. With that enabled you'd have no vibration leaking into the gyro data whatsoever with minimal filter latencies and I can't imagine that there is anything comparable on the market at the moment. Right now, the Fettec ESC is slightly above my BLHElis32 in noise profiles, RPM-Filters would -I guess- catapult it way ahead.

stackola commented 4 years ago

Bump

Can we get any update from the author on this?

lichtl commented 4 years ago

There is no plan to implement bidirectional DSHOT. The best is if Betaflight would directly support the Onewire protocol (which then would allow to get all telemetry data in real time (voltage/current/rpm).

stackola commented 4 years ago

Are you guys working on getting Onewire into BTFL, or do you just hope someone from BTFL will do it them self?

wuzle commented 4 years ago

I guess Onewire integration into Betaflight would be even better. In the end for the consumer it doesn't really matter where the juice comes from :)

There is also additional functionalities like Battery compensation features that we could enable when there's fast enough telemetry data (normal telemetry is not fast enough)

bkleiner commented 4 years ago

There is no plan to implement bidirectional DSHOT. The best is if Betaflight would directly support the Onewire protocol (which then would allow to get all telemetry data in real time (voltage/current/rpm).

Is there a specification document for OneWire (i guess its "just" serial?) to get the ball rolling on this.

rauar commented 4 years ago

There's a (probably very old) document on rcgroups - unclear how much it fits the current onewire implementation on fettec escs: https://www.rcgroups.com/forums/showatt.php?attachmentid=8524039&d=1450424877

It mentions a PWM-based trigger to receive telemetry...

@lichtl: Would be great if the fettec devs could share some specs so that there's a chance to get it implemented in Betaflight. Currently stuck without RPM filter using a Betaflight FC and a Fettec 4in1 😖

lichtl commented 4 years ago

Hi @rauar

please find attached 2 implementations (one for Arduino and the one used in KISS FC firmware). They do contain some documentation as well. Hope this helps for the start.

FETtecOneWire.zip FEttecESC_arduino.zip

stackola commented 4 years ago

@lichtl Are you guys actively working on getting this into BTFL, or are you just hoping and waiting for some community member to get around to that?

rauar commented 4 years ago

@lichtl thanks a lot for the files. will check them out as soon as i find some spare time.

@stackola check out this betaflight issue - i tried to reactive the discussion on a former request and the betaflight and blheli devs plus Felix from Fettec were commenting: https://github.com/betaflight/betaflight/pull/7264#issuecomment-713170259

Unfortunately I seems like there are 2 ways how to implement this and there's no agreement yet on one of those options. One option is to implement it in DSHOT on the signal line (like BLHeli) and Mike prefers this (avoid multiple implementations of the same "thing") and Felix seems to promote Oneshot (using a dedicated telemetry wire).

Not sure if they will agree on one of those options (I doubt it atm) - but I see the points of both sides.

I think the more people ask for support for RPM filtering when using Kiss/Fettec ESCs the higher the chances they come to an agreement.

Linjieqiang commented 3 years ago

@rauar Any news?

Linjieqiang commented 3 years ago

@ronlix Any docs about the Fettec Onewire?

stackola commented 3 years ago

It's been almost a year since you have claimed to be going into testing. @FETtec

Can your customers ever expect to get working RPM filters on betaflight or not?

krunked-fpv commented 3 years ago

Bruh. Lol. Give it up.

On Sun, Mar 21, 2021, 7:55 AM Willi K. @.***> wrote:

It's been almost a year since you have claimed to be going into testing. @FETtec https://github.com/FETtec

Can your customers ever expect to get working RPM filters on betaflight or not?

— You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub https://github.com/FETtec/Firmware/issues/3#issuecomment-803563858, or unsubscribe https://github.com/notifications/unsubscribe-auth/AKDU7JWOWRPT73GICVTS66LTEXNC3ANCNFSM4LGBFNYQ .

stackola commented 3 years ago

Bruh. Lol. Give it up.

No!

Bump. Give me bidrectional dshot!!!

stackola commented 3 years ago

Any day now!

krunked-fpv commented 3 years ago

Give it up. Lol

On Tue, Jun 29, 2021, 12:20 PM Willi K. @.***> wrote:

Any day now!

— You are receiving this because you commented. Reply to this email directly, view it on GitHub https://github.com/FETtec/Firmware/issues/3#issuecomment-870738800, or unsubscribe https://github.com/notifications/unsubscribe-auth/AKDU7JUN67JSVMEFKOOEHALTVHXDVANCNFSM4LGBFNYQ .

VolkerGoeschl commented 2 years ago

Never gonna give you up, never gonna let you down, never gonna run around to D-shot!

stackola commented 2 years ago

Never gonna give you up, never gonna let you down, never gonna run around to D-shot!

Found a fix: Sold my Fettec stuff and won't be buying any more.

homepods commented 12 months ago

with or without bidirectional dshot - does it matter? perhaps no. if you test side by side BF with rpm filtering/bidi shot and FT would you see a big difference or any difference at all?

stackola commented 12 months ago

@homepods It matters a lot. AFAIK, FT also uses some bidirectional protocol but it's homebrew and not compatible with BF.

homepods commented 12 months ago

@homepods It matters a lot. AFAIK, FT also uses some bidirectional protocol but it's homebrew and not compatible with BF.

As I understand FT reads through the TLM the motor rpm and does the filtering accordingly.

would you keep a fix pwm frequency or variable?