Brushless direct drive GIMBAL - big revolution for a few $

dr.tom · Post by **dr.tom** » Thu Jan 03, 2013 7:59 am

for some time DJI ZenMuse was THE ONLY one offering it,
price was somewhere in the 5000$ ballpark, (3500 gimbal + 1500$ flight controller needed to make it work)

showing off

http://www.youtube.com/watch?feature=pl ... 7DlcxuSuYk

wind or no wind, and no matter how you punch the sticks, the video is rock stable...
http://www.youtube.com/watch?v=XgLCR3bVEDU
http://www.youtube.com/watch?v=NRUa4yU5HSY

with price like that, in my whole country there is only one flying.

now let's get back to cheap stuff.. that's where the fun is 8-)

I'm not selling anything to be clear,

parts cost around 50$ for DIY style or if you don't want to make it by yourself,
there is an user you can contact on german forum RC FAN2,(he speaks english

)
or here: http://brushlessgimbal.de/

you need:
L6234D motor driver chip, 5$ each (2 needed for two motors=10$)
6050 well known IMU, 7$ free shipping
Arduino promini 7$ or even some empty mwii board 10-20$
(promini is most compact in size and cheap, if no promini available, empty mwc is better than populated,
because the IMU has to be on camera pad, not on model like in Multiwii, so it's more practical tu put only small IMU there than whole mwii board or arduino mini which need batteries also)
2 cheap brushless motors that you rewind with 0.15mm wire, bonus is they can be burned so you can get some for free in your rc club maybe

how smooth can DIY direct drive gimbal work, NOT Zenmuse but pretty close, for a fraction of a cost! servo gimbals, bye bye:
http://www.youtube.com/watch?feature=pl ... 56bWTFu65Y
http://www.youtube.com/watch?feature=pl ... HX_l4Yi0bg
https://www.youtube.com/watch?v=Prq5INQ ... r_embedded

not open source,
http://www.simplebgc.com/files/
even has a nice GUI, seems familiar

Thanks to RC FAN2, his version of code is public and free

http://code.google.com/p/brushless-gimbal/

the pcb design is also free
http://fpv-community.de/showthread.php? ... post252104
but if running of an multiwii board, you just need driver pcb, not the one for atmel...

posted just to get people interested,
so maybe someone will implement it into MWii, or make it better without implementing it, guys over there are open for suggestions

code is in arduino,
hardware IS compatible (I run it from MWii board without problems) http://www.youtube.com/watch?v=T1svUkQwgIo
it works far better than any servo gimbal out there

I'm no expert,
multiwii is open source so nothing got stolen if it gimbal code gets implemented, still could get downloaded by anyone on official wii code site,
both could even benefit, because I believe MWii has better IMU processing than this newly created code,
even if no implemetation, is worth taking a look into. it's cheaper than 2 good servos, and works better.

It can be used for small cameras like gopro,

http://www.youtube.com/watch?feature=pl ... HX_l4Yi0bg

and even for bigger ones >1kg for professionals.

http://www.youtube.com/watch?feature=pl ... qVn9WOEbaI

Hamburger · Post by **Hamburger** » Thu Jan 03, 2013 9:57 am

interesting approach.
I wrote to Alexej at simplebgc.com on the GPL open source issue. The GUI code is a copy of MWii gui code.

On RC FAN2's project:

and multiwii is open source so nothing got stolen if it gets implemented

not true (GPL is not equal to open source), but that project seems to have no relations to MWii other than being hardware compatible, which is ok (and smart).

I wish that project good luck.

germinbmxer · Post by **germinbmxer** » Thu Jan 03, 2013 1:13 pm

Olá dr.tom.
Pode escrever normalmente em seu idioma. Entendo um pouco o inglês, o resto uso no google translate.

Sou o Rafael(do Brasil) que postou recentemente no outro forum(fpv-community.de).
tenho interesse em ver seu progresso. tenho um Arduino soldado com um 6050.
Mas não sei como você montou seu driver para o motor(aquela placa com transistores e FET(eu acho) que dá pra ver em seu vídeo.
teria o esquema dela? Assim posso fazer testes aqui também.
Quando comecei, usei um ESC que tinha guardado. um TowerPro H40A, que usa um Atmega8. Assim, aproveitei para criar o firmware encima dele.

dr.tom · Post by **dr.tom** » Thu Jan 03, 2013 1:19 pm

No problem,
at the moment I am using DIY motor driver from parts available in local store.
(waiting for the smaller and better working one, L6234D from ebay, it's even cheaper than this parts needed for DIY version and no need for so much soldering!)
schematics are here: see attachment.

it would be great if you succeed in hacking a ESC,
some managed to get it to work, but didnt post how

some even have great results with BRUSHED motors!
see how quickly it compensates fast movements, but still has amazing precision for slow moving corrections :shock:

also not sharing how-to

http://vimeo.com/55463600
http://vimeo.com/56171458

albertoLG · Post by **albertoLG** » Thu Jan 03, 2013 2:34 pm

this is a great project... thank you

alexmos · Post by **alexmos** » Thu Jan 03, 2013 10:07 pm

Hello guys! I am an author of one of this project. I confirm that brushless gimbal work mush better than all servo gimbals I have tryed. And it is very easy to assemble this gimbal (you need H-bridge drivers, arduino, IMU sensor, rewound motors and simple mechanics).

MultiWii code is not good for it - we need very fast closed loop and only gyro raw data as main PID-controller source. My code is much simplier than multiwii, and code that german guys have published, looking pretty simple, too.

But don't wait quality like ZenMuse from it - there is many pitfails that dont let to get hi-end stabilization.

crashlander · Post by **crashlander** » Fri Jan 04, 2013 7:57 am

Hello!
Interesting project indeed!
@alexmos: use of brushed motors seems mechanically/electronically simpler so why you chose brushless (technical reasons or just availability)?

Regards
Andrej

dramida · Post by **dramida** » Fri Jan 04, 2013 11:00 pm

He used brushless motors in order to be able to control the magnetic thrust vector by simultaneously powering all 3 coils (i guess). I also want to know more details about how controller realize in witch position is at start-up.

germinbmxer · Post by **germinbmxer** » Sat Jan 05, 2013 12:57 am

dr.tom:
Eu vi estes videos usando BRUSHED.
Achei os resultados melhores que Brushless.
E como você mesmo falou, parece bem simples de montar.

alexmos · Post by **alexmos** » Sat Jan 05, 2013 11:39 am

I think Brushed motor will not work - it has high non-linearity when switching to next coil.

dramida wrote:He used brushless motors in order to be able to control the magnetic thrust vector by simultaneously powering all 3 coils (i guess). I also want to know more details about how controller realize in witch position is at start-up.

It is no matter wich position at start up. Just rotate magnetic field untill it will move camera (and IMU) to desired position. Only direction is matter and shoul be configured (or auto-detected at startup).

dr.tom · Post by **dr.tom** » Sat Jan 05, 2013 9:22 pm

someone posted a little educational video,
doesn't say what code he is using.

http://www.youtube.com/watch?feature=pl ... _8Kb_fXRrU

Jonit · Post by **Jonit** » Sat Jan 05, 2013 9:35 pm

love this sooo much!! It is only at an early stage of development but already it is so stable! I will build one of these in couple of months

gompf-2 · Post by **gompf-2** » Mon Jan 07, 2013 6:04 pm

Nice catch, dr.tom,

thanks for pointing to this before I dump all this boxex with CDR-Drives and "Conrad-BL"-parts my wife told me to dump during the new year cleanup. (because not touched for 5+ years, the boxes of course ;-)

Now I see a big recycling event on the horizon ;-)

.
For a single channel solution the old Plush 6a with Mega8 maybe worth a look as it brings a MCU, I2C(with some mods) and 3/2 of h-bridge on a very tiny PCB. I really disliker the change to SiLabs as with RFM12/22 connected the 6A was something like my "Atmel electric imp" (e.g. also good as combined rx/esc for LEGO Power Functions rc-car with only plugging a tsop1438 to the rc-port and some SW to drive 2/3 of the bridge for brushed motor and 1/3 for servo PPM; a pair of these is driving my warm water circulation pump, one as wireless switch in the bathroom, second powering the relais for the WILO, with Arduino/AES128 lib).

regards,
gompf

dr.tom · Post by **dr.tom** » Thu Jan 10, 2013 4:10 pm

give it a try, maybe you make something better than it is now

here are my test videos..
http://www.youtube.com/watch?v=k7E6p8cLt-U
http://www.youtube.com/watch?v=dSQo-r8Vdq8

gimbal has to be in perfect balance
http://www.youtube.com/watch?v=cqTl3QURUJs

dr.tom · Post by **dr.tom** » Thu Jan 10, 2013 5:10 pm

alex kindly posted his hex files public

http://www.simplebgc.com/eng/downloads/

can't get it to upload via ftdi to try it out...

edit: soldered ISP pins on atmel

flashed ok but it doesn't work,

guess we will have to wait for it to be available in shops... hope not 2 more months like now

skygizmo · Post by **skygizmo** » Sun Jan 27, 2013 11:28 pm

hey there is a program on his website that lets you upload hexa file. gonna try it tomorrow

dr.tom · Post by **dr.tom** » Mon Jan 28, 2013 8:33 am

here's my controller made by german PCB design,
I used only driver part of the PCB, controller part was not needed IMHO because I already had promini laying around, so I used it.

the code is now at this level
Brushless Gimbal FW_0.39 3.Test
(not my video)
hope it will get better, PatrikE from this forum started to work on MultiWii code for gimbal too,
works for now but when driving 2 motors it starts to jitter and have a great lag.
he will post when it will be ready for beta testing.

dr.tom · Post by **dr.tom** » Mon Jan 28, 2013 9:12 am

I got PM's asking for parts list, no secrets, no problem,
better to put it here so anyone could see if interested

IMU 6050
http://www.ebay.com/itm/370691521469...84.m1497.l2649
CPU 328p
http://www.ebay.de/itm/350646580746?...84.m1497.l2649
driver chip 2x L6234D
http://www.ebay.com/itm/L6234D-Manu-...item19d15dfd88
driver board PCB
http://code.google.com/p/brushless-gimb ... loads/list
http://brushless-gimbal.googlecode.c...dware_V1.1.zip
you send treiber(driver) platine schematics to this guy and he makes it and sends it back to you,
http://myworld.ebay.com/tedchen1632?_tr ... 7675.l2559
http://www.ebay.com/itm/1-2-Layers-PCB- ... 2c6b637e3b or you buy it on german forum, they have it unpopulated or populated (RTF)
motors you can also buy over there on german forum or by yourself.
I am still experimenting with different ones that i rewound by myself, I have 8 of them for now, as code got better I will sure do some more tests

if someone finds a better price for parts, please do post here, I just c/p ones that I used a month ago, now there may be better options

Jonit · Post by **Jonit** » Wed Jan 30, 2013 8:48 pm

whaaaaat

http://www.youtube.com/watch?v=e5enRVS8JxA

crazyhorse21 · Post by **crazyhorse21** » Thu Jan 31, 2013 3:23 am

thanks dr. tom,

pls could you share the link on the german forum, where they have it unpopulated or populated (RTF) ??

thanks in advance

CH

dr.tom · Post by **dr.tom** » Thu Jan 31, 2013 6:56 pm

Jonit wrote:whaaaaat http://www.youtube.com/watch?v=e5enRVS8JxA

that's Russian closed source controller
http://www.rcgroups.com/forums/showthread.php?t=1804109

I have 1 on route to me and I hope it works OK.

this is free open source code from german forum:

http://fpv-community.de/showthread.php? ... post282640

crazyhorse21 wrote:thanks dr. tom,

pls could you share the link on the german forum, where they have it unpopulated or populated (RTF) ??

thanks in advance

CH

1. http://fpv-community.de/showthread.php? ... Controller

2. http://fpv-community.de/showthread.php? ... er-50x50mm

you can always contact the german users via PM and ask them for empty boards,
or download free plans posted there and make it in your country, or send plan via e-mail to china (ebay link above in my post)
he will make whatever you want,

that's how I got my boards for this until alexmos started to sell his version.
now i can test both and see which works better for me

albertoLG · Post by **albertoLG** » Thu Jan 31, 2013 9:20 pm

Jonit wrote:whaaaaat http://www.youtube.com/watch?v=e5enRVS8JxA

THIS IS THE GIMBAL I WANT!!!!!

compact and don't need a tall gear to use it...

crazyhorse21 · Post by **crazyhorse21** » Thu Jan 31, 2013 9:24 pm

dr.tom,

thanks for the links

i also wanted to know if there are other alternatives for the driver chips ... sourcing them here is bit too difficult ...

thanks in advance

CH

dr.tom · Post by **dr.tom** » Thu Jan 31, 2013 11:19 pm

if you can't find them locally
5$ per piece, unlimited supply,
7-10days delivery time...
http://www.ebay.com/itm/L6234D-Manu-ST- ... 19d15dfd88
me and my friends bought them there, works as it should.
in other locations (parts stores locally in my country it costs around 40$ per piece!)

and here they are selling alex's controller alone, not too high price and it works 100%
all beta testers and those video where it says SIMPLE BGC use that controller.
http://www.csgshop.com/product.php?id_product=136

I ordered 1 for myself too

Aviator · Post by **Aviator** » Fri Feb 01, 2013 12:12 am

Dr Tom..
Just a quick question? If I have Arduino Nano, MPU6050 board all I need to do is get the driver board made, upload the firmware to Arduino and re-wire the motors and job done?

dr.tom · Post by **dr.tom** » Sun Feb 03, 2013 2:30 pm

Yes,
free german code is working much better than 7 days ago...
and it is getting better and better every day, like Multiwii

http://www.youtube.com/watch?feature=pl ... K01qRW95qI

Gimbal · Post by **Gimbal** » Tue Feb 05, 2013 9:35 am

Hi Dr Tom, tired to get a pcb from the kraut gays but no reply, do you by chance have another sours?

jpeti29 · Post by **jpeti29** » Tue Feb 05, 2013 10:01 am

Hi guys!

Do you think, that AlexMos's code could run on the german guys hardware?

Gimbal · Post by **Gimbal** » Tue Feb 05, 2013 10:07 am

I've have test it but couldn't get it running, it's loading with 115200 baud so you need a boot loader(optiboot?) with that speed, have loaded it with my Dragon without boot loader no success.

jpeti29 · Post by **jpeti29** » Tue Feb 05, 2013 10:24 am

Sorry, i forgot to mention, that i would like to connet an arduino pro mini with the german style motor control board, and use Alex's fw on it.

PatrikE · Post by **PatrikE** » Tue Feb 05, 2013 11:18 am

My experiment to drive a BLC gimbal with MWii
MWii BLC

Motor 1 uses A0,A1,A2 // Roll
Motor 2 uses 9 ,10 ,11 // Nick

Use together with dev 1317 gui.

joethe3rd · Post by **joethe3rd** » Tue Feb 05, 2013 11:26 pm

Just found this topic, thanks for all the great info! I am going to try getting my own gimbal going soon, with the german opensource or maybe with the Alexmos hardware now that it is becoming available for purchase.

PatrikE · Post by **PatrikE** » Wed Feb 06, 2013 1:05 pm

Could it be possible to modify SimonK esc code to work as a BLC?

joethe3rd · Post by **joethe3rd** » Wed Feb 06, 2013 2:56 pm

I was wondering about that too. There are also the ESC32 and OpenBLDC projects which are possible starting points. The OpenBLDC has not been that active in the last while, but I heard some of the developers were busy with the Quadshot and are coming back to OpenBLDC now.

Gimbal · Post by **Gimbal** » Wed Feb 06, 2013 2:57 pm

i guess, they using tree phase drivers so why not, more interesting would bee to have an open loop controller with 14bit magencoder on STM32 and 2.4mhz i2c.

KasparsL · Post by **KasparsL** » Wed Feb 06, 2013 3:31 pm

PatrikE wrote:Could it be possible to modify SimonK esc code to work as a BLC?

I was thinking of using some cheap Brushless ESCs - remove the controller chip and use 3 half bridge drivers left. Your idea is even better! If the outputs used to drive the motor are hardware PWM, it is duable!

skygizmo · Post by **skygizmo** » Wed Feb 06, 2013 10:03 pm

hey does anyone have list of components for the drive circuit pcb? and what size smd components?

Thanks

hexa · Post by **hexa** » Thu Feb 07, 2013 4:56 am

come on coderes and hardware folks. lets get the ball rolling on a english open source version circuit board

Gimbal · Post by **Gimbal** » Thu Feb 07, 2013 10:34 am

here you is hardware files for eagle, size wouldent be to hard to find out

http://code.google.com/p/brushless-gimb ... p&can=2&q=

hexa · Post by **hexa** » Thu Feb 07, 2013 11:59 am

Partlist

Exported from Gimbal Controler.sch at 07/02/2013 10:55

EAGLE Version 6.4.0 Copyright (c) 1988-2013 CadSoft

Assembly variant:

Part Value Device Package Library Sheet

C1 100n CAP0805 0805 SparkFun 1
C2 100n CAP0805 0805 SparkFun 1
C3 100n CAP0805 0805 SparkFun 1
C4 100n CAP0805 0805 SparkFun 1
C5 100n CAP0805 0805 SparkFun 1
C6 100µ CAP_POLD PANASONIC_D SparkFun 1
C7 100µ CAP_POLD PANASONIC_D SparkFun 1
C8 100n CAP0805 0805 SparkFun 1
C16 1uF CAP0805 0805 SparkFun 1
C17 1uF CAP0805 0805 SparkFun 1
C18 10n CAP0805 0805 SparkFun 1
C19 10n CAP0805 0805 SparkFun 1
C20 0.22uF CAP0805 0805 SparkFun 1
C21 0.22uF CAP0805 0805 SparkFun 1
C24 100n CAP0805 0805 SparkFun 1
C25 100n CAP0805 0805 SparkFun 1
C29 100n CAP0805 0805 SparkFun 1
D1 ATMEGA328p-AU ATMEGA168-AU TQFP32-08 Arduino-AVR 1
D2 FT232RL FT232RL SSOP28 ftdichip 1
D3 T1 L6234 SO20POWER2 L6234 1
D4 T2 L6234 SO20POWER2 L6234 1
F1 FUSE_SMD_10MM FUSE_SMD_10MM SMD_FUSE_10MM f-lf-omniblok-s 1
H1 T67K ROT LS_T679-D2E2-1 PLCC2 led 1
H2 LG T67K GRUEN LG_T679-E1F1-1 PLCC2 led 1
JP1 M02PTH 1X02 SparkFun 1
JP2 M05PTH 1X05 SparkFun 1
JP3 M04PTH 1X04 SparkFun 1
JP4 M06SIP 1X06 SparkFun 1
JP5 M06SIP 1X06 SparkFun 1
JP6 M03PTH 1X03 SparkFun 1
JP7 M03PTH 1X03 SparkFun 1
R1 10k RESISTOR0805-RES 0805 SparkFun 1
R2 10k RESISTOR0805-RES 0805 SparkFun 1
R3 1k RESISTOR0805-RES 0805 SparkFun 1
R4 330R RESISTOR0805-RES 0805 SparkFun 1
R5 330R RESISTOR0805-RES 0805 SparkFun 1
R6 1k RESISTOR0805-RES 0805 SparkFun 1
R21 10k RESISTOR0805-RES 0805 SparkFun 1
V1 DIODE-DO214AC DO214AC diode 1
V2 BAS40-04 BAS40-04 SOT23 diode 1
V3 1N4148 DIODE-MINIMELF MINIMELF diode 1
V4 1N4148 DIODE-MINIMELF MINIMELF diode 1
V5 1N4148 DIODE-MINIMELF MINIMELF diode 1
V6 1N4148 DIODE-MINIMELF MINIMELF diode 1
V7 78L05F 78L05F SOT89 linear 1
X2 USBOLD USBOLD USB-MINIB-OLD SparkFun 1
Y7 16mhz RESONATORSMD RESONATOR-SMD SparkFun 1

Download eagle pcb and choose free ware when installing, then click export part list

Gimbal · Post by **Gimbal** » Thu Feb 07, 2013 12:52 pm

Well I'm about to make a couple of PCB using toner transfer, a bit messy thou, planning to use teensy3 with mag encoder and then i would be able to run motors without rewinding, to achieve this it need's open loop feedback from encoder and PID pwm control, it feels like their can be some gain by having the imu mounted on the frame instead of the gimbal?

PatrikE · Post by **PatrikE** » Thu Feb 07, 2013 12:55 pm

The concept is to use the imu on the gimbal instead of a encoder as I understand.

Gimbal · Post by **Gimbal** » Thu Feb 07, 2013 1:10 pm

that's true if you going with present systems, but then it will always be one step behind, with the imu on the frame and knowing the position of the gimbal you can use high torque motors with pid

btw encoder are like 5$ and the mag 1$ or you can get free samples from Austrianmicrosystem, mail them and you get 3 for free as5048b 14bit, thats i2c witch are able to run at 2.4mhz

hexa · Post by **hexa** » Thu Feb 07, 2013 4:14 pm

Gimbal wrote:that's true if you going with present systems, but then it will always be one step behind, with the imu on the frame and knowing the position of the gimbal you can use high torque motors with pid

btw encoder are like 5$ and the mag 1$ or you can get free samples from Austrianmicrosystem, mail them and you get 3 for free as5048b 14bit, thats i2c witch are able to run at 2.4mhz

sounds good.
will need to port the code to that processor?

skygizmo · Post by **skygizmo** » Fri Feb 08, 2013 9:33 pm

Hi, succeeded in obtaining list of parts.

but have trouble finding some parts as
C12 CAP_POLPTH1 CPOL-RADIAL-100UF-25V
D1 1N4148 diode-MINIMELF MINIMELF diode
C10 0.22uF CAP0805 0805
someone who has a good place to buy? and even order numbers

dr.tom · Post by **dr.tom** » Sat Feb 09, 2013 9:05 am

I received a few PMs asking for parts and where does what go,
people, please install eagle program, and open the schematics,
there you can click on ''i'' icon on the left, and click on anything you like,
it will show it's name and specifications.

I took some screenshots even to show how it works.

right now I am playing with alexmos's controller from csg

Gimbal · Post by **Gimbal** » Sat Feb 09, 2013 11:57 am

Hi dr.Tom, nice board I'm just curious about the ticker is it 16 or 20 MHz, have had som problem running code on 328p 16 Mhz

msev · Post by **msev** » Sat Feb 09, 2013 1:52 pm

Dr.Tom so that board from cgs is directly compatible with that .hex alexmos has put on his site? Can you reverse engineer the board and draw a schematic

dr.tom · Post by **dr.tom** » Sat Feb 09, 2013 5:29 pm

Here's my first run of alex's board

http://www.youtube.com/watch?v=KUn-M5rJij0

hexa · Post by **hexa** » Sun Feb 10, 2013 11:02 am

To run alex hex you will need his special boot loader which i think is fuse bit so wont be able to dump alex bootloader from the arv.
Alex hex is probably encrypted with inscription keys embedded in the boot-loader,