Is it possible: 8 motors in dshot?

(Gal Nitzan) #1

Hi,
I was wandering, Is it possible to connect somehow 8 motors in DShot? Cube Black
Thank you
Gal

(Cornel Fudulu) #2

I tried DShot300 (as this was the lowest protocol an APD ESC will take) on Cube Black’s AUX port and it didn’t work. I read that 4 are possible on a Pixhawk 4 (STM32F7), but then 5th and 6th no longer worked. I have Orange Cubes with H7 and will test DShot soon, but there’s only 6 AUX ports available.

(Gal Nitzan) #3

Ok, answering my own question here, I should have googled better.

The Pixhawk has no dedicated digital output or input pins on its DF13 connectors, but you can assign up to 6 of the “AUX SERVO” connectors to be digital outputs/inputs

So basically you can have a Hexacopter with DShot ESCs but not Octocopter, which makes me wonder why Cube has only 6 aux and not 8? Aren’t we in the digital age?

#4

You can have DSHot on main, just not feedback

The future is CAN, not DShot, get with the secure Digital age :slight_smile:

PWM and DSHot is pre 2020… it’s time to move on.

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(Gal Nitzan) #5

Hi @philip,

Sorry I’m kind of a beginner so I didn’t understand the “feedback” you mentioned? do you mean telemetry will not work?

Well, I looked it up and it comes with a bit of a hefty tag price (8x$71 usd) :cold_sweat:

Thanks,
Gal

#6

what can bus esc did you look up? If you don’t need bunch of amps holybro makes these20 amp can esc that pavel from zubax has helped them with. I have a set just working on a different build will confirm tonight they work with pixhawk for you!

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(Gal Nitzan) #7

Hi @Matt.C, thank you for the answer and link, maybe I can join the digital age after all :smile:, however I need to think what to do with my two T-motor F55A 4in1 which I already own.

I plan a 850 mm quad in X8 configuration and I planned to connect every 4 motors to one 4in1 esc.

Anyway, thank you for the pointer
Gal

#8

Yes, 8 without telemetry.

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#9

Save’ um and build a wee little quad for beta testing, will be a bit of overkill but oh well!

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(Gal Nitzan) #10

So let me see if I understand:
I can set the MOT_PWM_TYPE=4, SERVO1_FUNCTION-SERVO8_FUNCTION=33-40, SERVO_BLH_AUTO=1
and all shall work including passthru, except I will not be getting the telemetry on serial5 anymore?

Thank you for taking the time to answer me, much appreciated.
Gal

(Cornel Fudulu) #11

Do tell, please.
I tried DShot 300 from a Black Cube AUX1 port to an APD X-Class 120A ESC - as DShot300 is the minimum protocol it accepts - and the result was ugly: weird response and ESC resets. Same was experienced on an old Pixhawk 1 AUX1 port, so I excluded F4-based FCs from possible builds.
There are reports it works on a Pixracer (F4 ugh!), and also on Pixhawk4 (F7), but only to the extent of 4 ESCs. Time constraints have prohibited me testing it on a H7 Orange Cube.

(Gal Nitzan) #12

Well, I’m just a hobbyist in its dippers as of yet. I need to learn to walk before I run :smile:.

I shall try the UAVCAN ESC after I shall crash the new one :wink:
Gal

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#13

Aux is direct connection two way comms with the FMU

Main is one way protected high current output from the IO chip

Aux has 6 pins
Main has 8 pins

There is no logical reason for any difference between chips in the Aux, other than some cheaper non genuine boards having no protection on the PWM lines.

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(Gal Nitzan) #14

Well, lucky for me I use the Cube :wink:
Thank you
Gal

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