xfce

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LP for brushed quad question
« on: May 13, 2016, 03:22:53 am »
I have custom the CC3D for brushed quad:
add mosfet, charge ic, 5v dcdc etc, and the same size as scisky fc,

now it fly well  use dronin, as below, but dronin/taulabs don't have the Rattitude and Cruise-control,

so it's hard to flip the small quad, developers, do you have the plan to support brushed quad?
I want to use Rattitude and cruise-control for flip this, thanks.





« Last Edit: May 13, 2016, 03:26:12 am by xfce »

hwh

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Re: LP for brushed quad question
« Reply #1 on: May 13, 2016, 03:41:23 am »
Cute board.  Something like the Micro Scisky but cc3d based instead of naza.   I think I've seen a frame like that on one of the 3d printing repositories. I keep thinking of trying one.

You can probably run brushed with the current software, f5soh worked out settings for it when someone asked but didn't have a board to test them on, he just used a scope to look at the waveform.

I can't find the post but my notes say:

System tab > UavoBrowser > ActuatorSettings
bankupdatefreq = 4000 Hz
channel max = 250 us
channel neutral = 5 us
channel min = 0 us

If I recall correctly that gave a more or less standard pwm signal suitable for driving a FET.  It should give you something to experiment with anyway.

-Hank

edit: I found the post, it has a video showing the waveform.  https://forum.librepilot.org/index.php?topic=1501.msg11312#msg11312
« Last Edit: May 13, 2016, 04:04:26 am by hwh »

xfce

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Re: LP for brushed quad question
« Reply #2 on: May 13, 2016, 04:30:41 am »
Cute board.  Something like the Micro Scisky but cc3d based instead of naza.   I think I've seen a frame like that on one of the 3d printing repositories. I keep thinking of trying one.

You can probably run brushed with the current software, f5soh worked out settings for it when someone asked but didn't have a board to test them on, he just used a scope to look at the waveform.

I can't find the post but my notes say:

System tab > UavoBrowser > ActuatorSettings
bankupdatefreq = 4000 Hz
channel max = 250 us
channel neutral = 5 us
channel min = 0 us

If I recall correctly that gave a more or less standard pwm signal suitable for driving a FET.  It should give you something to experiment with anyway.

-Hank

edit: I found the post, it has a video showing the waveform.  https://forum.librepilot.org/index.php?topic=1501.msg11312#msg11312

OK, I will have a try,
does the max update freq is only 4KHz?  it's the audio frequency, may very noisy, could set higher, like taulabs/dronin's 16666KHz?

hwh

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Re: LP for brushed quad question
« Reply #3 on: May 13, 2016, 04:51:35 am »
I don't know, I just remembered f5soh posting that in response to a question.  Try it and see.

And please let me know what you find out and I'll add it to my store of wisdom...   :)

f5soh

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Re: LP for brushed quad question
« Reply #4 on: May 13, 2016, 09:28:01 pm »
From the test i did i only used 4Khz because higher frequency values cause high CPU for some reason with CC3D.

mr_w

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Re: LP for brushed quad question
« Reply #5 on: May 18, 2016, 12:05:24 am »
Hi xfce,

just to jump in with some updated info.

You can go safely above 4khz if you configure CC3D receiver port to one of the OneShot modes. Everything else marked with NoOneShot is not compatible with high frequency, and will hang your board due to excessive cpu usage.

There is however issue with PWM resolution you will get, since currently base clock that runs pwm timer is just 1Mhz, and having PWM output run at for example 40khz will get you only mere 25 steps.

This is however being worked on, and one of the future releases will bring proper "Brushed" mode.


xfce

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Re: LP for brushed quad question
« Reply #6 on: June 07, 2016, 04:09:52 pm »
Hi xfce,

just to jump in with some updated info.

You can go safely above 4khz if you configure CC3D receiver port to one of the OneShot modes. Everything else marked with NoOneShot is not compatible with high frequency, and will hang your board due to excessive cpu usage.

There is however issue with PWM resolution you will get, since currently base clock that runs pwm timer is just 1Mhz, and having PWM output run at for example 40khz will get you only mere 25 steps.

This is however being worked on, and one of the future releases will bring proper "Brushed" mode.
Ok, thanks. Waiting for your update, right now I am use dronin, it is perfect.

xfce

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Re: LP for brushed quad question
« Reply #7 on: September 16, 2016, 08:40:41 am »
Hi all
    I have use the 16.09RC1 for my cc3d brushed, but seems the output not work, the channelmin can only set to 500us, even when you set them to 0us in the system setting. so when power on the propellers spin, please give some help thanks.

    attatched is my current setting

f5soh

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Re: LP for brushed quad question
« Reply #8 on: September 16, 2016, 08:06:41 pm »
Did you try with this settings ?



Since you don't save in Gui / Output tab the custom settings saved from UavoBrowser should still .

xfce

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Re: LP for brushed quad question
« Reply #9 on: September 17, 2016, 04:52:46 am »
Did you try with this settings ?



Since you don't save in Gui / Output tab the custom settings saved from UavoBrowser should still .

OK, thanks just fixed. my settings are OK, just ignore the GUI OUTPUT setting
stock PIDs are OK, fly perfectly. thanks.
BTW, the 16.09rc1 do not support cc3d for autotune?

f5soh

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Re: LP for brushed quad question
« Reply #10 on: September 17, 2016, 10:22:39 am »
That right, Autotune do not run using CC3D.

xfce

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Re: LP for brushed quad question
« Reply #11 on: September 17, 2016, 03:19:33 pm »
i think maybe no need to use autotune for the brushed :)

librepilot 16.09rc1

use oplink for telemetry and PPM, devo7e with oplink and bluetooth, it's cool


and the fly as below


« Last Edit: September 17, 2016, 03:25:44 pm by xfce »

Brian

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Re: LP for brushed quad question
« Reply #12 on: September 17, 2016, 07:24:02 pm »
That looks very nice!

Are you still using the stop PIDs?

I have a port to the Brushed Sparky that I plan to push soon.  The first test flight wasn't very good, but I think my props were too small.  I now have bigger props and will probably try it again this weekend.

Also, what are you using for an antenna on the OPLInk on the Quad?  That's the biggest drawback, I think, for OPLink on a nano, is that the antenna is so big.

xfce

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Re: LP for brushed quad question
« Reply #13 on: September 18, 2016, 02:42:54 am »
yes,all default settings. but try to flip no sucess.
i diy the oplink, remove usb and io sockets and some other compents, use a 17mm wire for antenna.
45mm propellers
150mA battery
720 motors,4200kv

Re: LP for brushed quad question
« Reply #14 on: October 22, 2016, 10:55:41 am »
System tab > UavoBrowser > ActuatorSettings
bankupdatefreq = 4000 Hz
channel max = 250 us
channel neutral = 5 us
channel min = 0 us


I come back to this. I use a CC3D brushed board from Bangood and use LibrePilot 16.09 RC2 but with this ActuatorSettings above the motors work very low.

When I change the channel max to 32000 all is working very well. But I don't know is that ok or not.

Any help?