User Info

 
 
Welcome, Guest. Please login or register.
Did you miss your activation email?

MultiRotorUK ShoutBox

Refresh History
  • atomiclama: Cheers, already have bog standard rucsacs, looking for something with a bit easier access to the internals
    February 15, 2018, 13:12:41
  • CornishMule: Atomiclama, I also had the CS300 but recently got [link] It's big enough to put the Taranis X9D case inside, fatshark case, Lipo bag, a couple of tool bags, launch pad, monitor, laptop and copious props. 2 quads strapped to the front.
    February 15, 2018, 11:29:36
  • atomiclama: Cheers Hozza
    February 14, 2018, 09:00:06
  • yama: hooked on 90mm brushless drones now:)
    February 11, 2018, 15:45:24
  • Hozza: Not found it uncomfortable, but I've probably only walked a mile :laugh:
    February 10, 2018, 17:44:20
  • atomiclama: I'm looking for a new pack as my current one is falling apart.
    February 10, 2018, 11:29:39
  • atomiclama: Don't like the look of the padding on the back.
    February 10, 2018, 11:28:50
  • atomiclama: Hozza, how comfortable is it for a long hike?
    February 10, 2018, 11:28:24
  • Hozza: I have the CS300 [link] bloody good back pack, everything I need inside and 2 quads straped to the front.
    February 10, 2018, 10:13:43
  • Andy7: Sweet! Fixed the USBs on my laptop - been hitting DRL sim with my QX7 all weekend
    February 04, 2018, 21:18:03
  • Bad Raven: Hope the fish are alright........   :laugh:
    February 04, 2018, 18:50:14
  • shawdreamer: hmmm Im feeling a little underwelming here, sorta lacking.... I stubbed my toe earlier on the fishtank stand.... that sorta counts right?
    February 04, 2018, 18:40:09
  • Friskle: Buggered more than Anything atm, struggling walking, getting badly out of breath, hopefully next stent in a few weeks will cure that :)
    February 04, 2018, 15:51:59
  • Andy7: Yikes! Sounds like it'a worked. How you feeling?
    February 03, 2018, 10:49:59
  • Friskle: just had stents fitted in the heart..rather a serious heart attack.. never saw it coming at all :(
    February 03, 2018, 03:58:02
  • VaNDAL_UK: Check the photos and see who is wearing to jacket with the most pockets!
    February 02, 2018, 17:02:23
  • DarkButterfly: Had a quick look at it
    February 02, 2018, 14:09:26
  • Gaza07: So who's enjoying reading the new BMFA mag  :hmm:
    February 02, 2018, 12:10:53
  • DarkButterfly: :laugh: :laugh:
    February 01, 2018, 18:44:11
  • hoverfly: Thanks D.B.  they just put a catheter  in ,I think they are taking the pi$$.... :rofl:
    February 01, 2018, 18:28:41

Who's Online

Theme Selection



Forum Default

Permanently

Author Topic: Flight Controller with PWM output to Little Bee ESC  (Read 165 times)

Offline Craigom

  • Trade Count: (0)
  • Newbie
  • *
  • Posts: 5
  • Liked: 0
  • Tricopter, one prop short of a Quadcopter
Flight Controller with PWM output to Little Bee ESC
« on: February 08, 2018, 13:45:28 »
Hi

I have utilised a flight control board from a Sky Drone Pro V2 from (Men Kind), I'm looking at using the PWM output signal that was wired to the gate of the N- junction Moffet, to provide a PWM input to a little Bee ESC 20A.

I can see through the Heli_B software configurator that you can enable the PWM input? is this PWM input able to accept 3.2Volts at 24kHZ? please refer to the attached picture. I scoped the PWM signal from the Flight controller and this is the max voltage and Frequency when the throttle power is at 100%. I wanted to run a test through buying a Little Bee ESC, but wanted to be sure this could be done through theory.

<br /><br />

Kind Regards

Craig

Offline atomiclama

  • Trade Count: (3)
  • Hero Member
  • *****
  • Posts: 2222
  • Liked: 673
  • Country: gb
  • Uhh! What's that then, Oh! new project.
Re: Flight Controller with PWM output to Little Bee ESC
« Reply #1 on: February 08, 2018, 14:38:34 »
In short no.

For PWM as used in the RC world it is a pulse that goes from ~1000us min to 2000us max
Update frequency then will have a max of <500Hz

If you are scoping something up at 24kHz then that is not a normal PWM signal. Probably one of the other control methods from the FC to the ESC, oneshot dshot or multishot
Wasdale X, Ow that hurt

Offline Craigom

  • Trade Count: (0)
  • Newbie
  • *
  • Posts: 5
  • Liked: 0
  • Tricopter, one prop short of a Quadcopter
Re: Flight Controller with PWM output to Little Bee ESC
« Reply #2 on: February 08, 2018, 15:43:51 »
Thanks Atomiclama

So are you saying the flight controller signal is not PWM? I assumed it was?

You reckon this is another signal output?

Offline Cheredanine

  • Trade Count: (0)
  • Hero Member
  • *****
  • Posts: 4130
  • Liked: 924
  • Country: gb
  • Everything you have been told is a lie
Re: Flight Controller with PWM output to Little Bee ESC
« Reply #3 on: February 08, 2018, 15:57:40 »
As llama said, pwm can not run faster than 500hz because the pulse length is up to 2000us, actually it can’t even reach 500hz because you need quiescence between pulses
There are a number of faster pwm based protocols;
Oneshot125 (4khz max)
Oneshot42 (just under 12khz max)
Multishot (40khz max)
Anything semi decent will be running serial protocols rather than pwm, usually dshot (the subsequent number is the frame rate)

Offline Craigom

  • Trade Count: (0)
  • Newbie
  • *
  • Posts: 5
  • Liked: 0
  • Tricopter, one prop short of a Quadcopter
Re: Flight Controller with PWM output to Little Bee ESC
« Reply #4 on: February 08, 2018, 16:32:10 »
Hi Cheredanine,

I measured the Flight controller output, as per the Image below and measured 24KHz the pulse length was 43us. would you know what band this would fit in or whether the Protocol type can be recognised ? reason been there is no programming port on the Flight controller as I have utilise it from a Sky Quad Pro V2. ( building a racing drone on the cheap). If I can see what protocol this is I can then do a Test on a ESC to see if I can control from the Flight controller. ( reverse engineering really).

Kind regards




Offline ched999uk

  • Trade Count: (0)
  • Hero Member
  • *****
  • Posts: 2171
  • Liked: 509
  • Country: gb
Re: Flight Controller with PWM output to Little Bee ESC
« Reply #5 on: February 08, 2018, 17:01:55 »
Just to say I think you might be trying too hard. All credit to you for taking time to try and work things out.
If the flight controller was not designed for the quad you are building and cant be 'programmed' it will never fly well. If you can't change PIDs, type of rx, flight modes, orientation of FC......... etc then it really isn't worth the effort.
You can get cheap Flight controllers like say a CC3D Atom https://goo.gl/SeNFHb for less than £10. It is by no means cutting edge but should get you airborne.
To be honest with an non programmable Flight Controller, unknown esc and motors that may not be suitable for the size of frame/props you need you will find it very difficult to get a stable easy to fly 'racing quad'.
Just looked up the quad you mention Sky Drone Pro V2.
The motors look like they are brushed so you cant use brushless esc!!!

Can you list the components you have or are thinking of getting and the frame, props, batteries etc and we can see how best you can use as much as possible.


Offline Cheredanine

  • Trade Count: (0)
  • Hero Member
  • *****
  • Posts: 4130
  • Liked: 924
  • Country: gb
  • Everything you have been told is a lie
Re: Flight Controller with PWM output to Little Bee ESC
« Reply #6 on: February 08, 2018, 17:38:06 »
Done a bit of digging, that quad is brushed.
It has a brushed flight controller for brushed motors.
You don’t use escs for brushed systems
(Unless it is a tinywhoop you use rubbish bins for brushed systems)
All the racing quads you see are running brushless motors.
Get an omnibus or something equally cheap if you want to build a cheap racer

Offline Craigom

  • Trade Count: (0)
  • Newbie
  • *
  • Posts: 5
  • Liked: 0
  • Tricopter, one prop short of a Quadcopter
Re: Flight Controller with PWM output to Little Bee ESC
« Reply #7 on: February 09, 2018, 08:15:32 »
Just looked up the quad you mention Sky Drone Pro V2.
The motors look like they are brushed so you cant use brushless esc!!!

Can you list the components you have or are thinking of getting and the frame, props, batteries etc and we can see how best you can use as much as possible.


Hi Ched

thank you for your response, yes the Sky drone 2 Pro is a brushed Motor controller, however I have now removed the N-Juntion Moffets that switch the Negative current from the brushed motor.

The gate signal (Unknown PWM signal) to the N junction Moffet will now be wired direct to an ESC. The ESC will control the 3 phase brushless motor.

Can the Bands be changed in the ESC to accommodate for the 3.2V  signal @ 24kHz.

So list of components

> ZMR 250 Frame with low rider spacer
>Little Bee 20A ESCs (4 off)
>Sky Quad Pro V2 flight controller
>PDB board for 3S Battery
>11.4 to 5V voltage regulator board for FC supply.
>Race Star BR2204 2300KV motors running 3S.
>6x3 bull nose props.

Let me know what you think.



Offline ched999uk

  • Trade Count: (0)
  • Hero Member
  • *****
  • Posts: 2171
  • Liked: 509
  • Country: gb
Re: Flight Controller with PWM output to Little Bee ESC
« Reply #8 on: February 09, 2018, 11:20:03 »
however I have now removed the N-Juntion Moffets that switch the Negative current from the brushed motor.

The gate signal (Unknown PWM signal) to the N junction Moffet will now be wired direct to an ESC. The ESC will control the 3 phase brushless motor.

Can the Bands be changed in the ESC to accommodate for the 3.2V  signal @ 24kHz.

So list of components

> ZMR 250 Frame with low rider spacer
>Little Bee 20A ESCs (4 off)
>Sky Quad Pro V2 flight controller
>PDB board for 3S Battery
>11.4 to 5V voltage regulator board for FC supply.
>Race Star BR2204 2300KV motors running 3S.
>6x3 bull nose props.

Let me know what you think.
OK so it sounds like you have an understanding of electronics. Have a read up on PID (Proportional, Integral and Derivative) control systems. You will see they are complex and some might say a 'Black Art'.

Without being able to change PID settings on the FC your quad will fly very badly if not uncontrollably as it was originally designed for a specific brushed quad. I cant stress enough to get a FC that is suitable, a cheap F3 should only be about £12. It can then run BetaFight and you will have access to all the settings but as the FC Software is set up for brushless quads you will probably not have to play with pids much if at all.
I commend you for trying to get the fc to work but really it wont be worth the effort and it will be unflyable.

I would suggest 5" props and not bull nose ones as they generate more lift but pull proportionately much more current.

Offline Craigom

  • Trade Count: (0)
  • Newbie
  • *
  • Posts: 5
  • Liked: 0
  • Tricopter, one prop short of a Quadcopter
Re: Flight Controller with PWM output to Little Bee ESC
« Reply #9 on: February 09, 2018, 11:47:26 »
Thanks Ched

main reason really for using the flight control is so I had a paired transmitter, receiver.

I have had a look online and I can buy a FrSKy i6 pretty cheap with a receiver, so I could you I may go ahead with my orginal project part list.

> CL Racing F4S FC with integrated PDB
> 4S Lipo 70CC Battery
>Swift Eagle Pro 2 Camera Module
>AKK Vtx 5.8Ghz 40 Channel Video transmitter
>4x ESCs Little Bee 30A
>BR2205 2300Kv brushless motors
>5045 Props

Offline ched999uk

  • Trade Count: (0)
  • Hero Member
  • *****
  • Posts: 2171
  • Liked: 509
  • Country: gb
Re: Flight Controller with PWM output to Little Bee ESC
« Reply #10 on: February 09, 2018, 12:04:41 »
Just a quick reply. I have i6 radio and find it good  can be flashed to 14 channels and better stuff.
List looks OK. I will have a better look later.

Offline ched999uk

  • Trade Count: (0)
  • Hero Member
  • *****
  • Posts: 2171
  • Liked: 509
  • Country: gb
Re: Flight Controller with PWM output to Little Bee ESC
« Reply #11 on: February 09, 2018, 18:58:14 »
Thanks Ched

main reason really for using the flight control is so I had a paired transmitter, receiver.

I have had a look online and I can buy a FrSKy i6 pretty cheap with a receiver, so I could you I may go ahead with my orginal project part list.

> CL Racing F4S FC with integrated PDB
> 4S Lipo 70CC Battery
>Swift Eagle Pro 2 Camera Module
>AKK Vtx 5.8Ghz 40 Channel Video transmitter
>4x ESCs Little Bee 30A
>BR2205 2300Kv brushless motors
>5045 Props

OK so here are my comments.
CL racing F4 FC is a reasonable FC with BetaFlight OSB build in and power distribution which makes wiring easier.
4S 70C lipo about 1500mAh max any bigger will be too heavy.
Swift Eagle 2 - interesting choice. Most goggles are 4:3 ratio so most people go for 4:3 ratio camera. The one you have chosen is switchable between 16:9 or 4:3 but it seems a little more expensive than you need. It also uses a CMOS sensor which, while they have improved, are more susceptible to vibration causing jello (wobbly images). The Foxeer Arrow V3 is £12 cheaper uses a CCD (better ) sensor. It is teh same size. https://www.quadcopters.co.uk/fpv-video-cameras/foxeer-arrow-v3-fpv-camera-25mm-with-osd-and-audio
AKK Vtx - No idea on that one, can't seem to find price etc. Have a look at Matek 40CH VTX 5.8GHZ HV with BFCMS Control https://www.quadcopters.co.uk/58ghz-video-transmitters-and-receivers/matek-40ch-vtx-58ghz-hv-with-bfcms-control It's about £20 and can be controlled via the Flight Controller i.e. change frequency and power, handy if you fly with others.
The escs should be fine but make sure they are BlHeli_S or _32. These ones are by a reputable manufacturer https://www.quadcopters.co.uk/racing-drone-escs/spedix-es30-hv-lite-30a-2-4s-blhelis-esc-2778
The BR2205 motors I assume are RacerStar. They are budget ones and they wont give as high a thrust as some but I use them on my Martian3 and find them good.
Props 5045 triblades. Sound about right. I have some KingKong 5045 triblades on my Martian3 and although there are better props I find these very resilient to crashes. I have crashed quite a lot and not broken one yet!!!

I have had my i6 for coming on 3 years and I broke a gimbal (dropped computer psu, psu for lipo charger on it) and had one go faulty. Bought a new one £10 delivered next day and used the bits from faulty one to fix the one I broke (kept in parts bin :) ). So it does stand up fairly well and spares are available  ::)
I have upgraded the firmware via a FTDI adapter ( about £3 on ebay) to make it 14 channels which also adds a timer (useful to time flights so you dont damage battery) and telemetry alarms. The newer version is even better.
As for a rx, ideally a x6b is small, light and can provide flight battery voltage back to tx so you can monitor it in flight.
I am sure someone else will have a different opinions which would be good to see.
If you are willing to wait a few weeks for delivery I can point you in the right direction that will save you a few quid.