490HZ ESC really ought to change

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octopus
Posts: 5
Joined: Tue Feb 05, 2013 7:21 am

490HZ ESC really ought to change

Post by octopus »

As long as GLB is selling ESCs in four packs like these (http://www.goodluckbuy.com/index.php?ta ... t_id=77771) and distributing them with MultiWii boards, there really ought to be code for refresh rates less than 490Hz. These ESCs work really well at 400Hz, but not at 490Hz. Output.ino really needs to have an option, imho. Took me hours just to figure out what the problem even was. Then a few more hours to find a patch but only for v2.0. The patch I found had typos so I had to fix those, and I would much rather use the later v2.1 code :(

Please, somebody provide code that works at a more widely supported refresh rate.

timecop
Posts: 1880
Joined: Fri Sep 02, 2011 4:48 pm

Re: 490HZ ESC really ought to change

Post by timecop »

what the fuck are you talking about.
those are just usual shit escs, they are trash regardless of output rate, flash atmega stuff with simonk and forget wasting time + money on that crap. the only "400Hz" on that esc is a sticker, you gonna believe a sticker makes shit fly betteR? ha ha.

octopus
Posts: 5
Joined: Tue Feb 05, 2013 7:21 am

Re: 490HZ ESC really ought to change

Post by octopus »

They work wonderfully at 400Hz. Ive used them at 400Hz. You're a knob. You are completely clueless. Way to welcome a newcomer. Go tell your Momma what a jackass you are.

timecop
Posts: 1880
Joined: Fri Sep 02, 2011 4:48 pm

Re: 490HZ ESC really ought to change

Post by timecop »

Any refresh rate > 200-250Hz with proper firmware doesn't mean shit, as there isn't enough revolutions between each update to make any difference. You gonna tell me motor + prop can change speed drastically during half a revolution? Riight.

Just like going from 400 to 490 isn't gonna make any difference.

octopus
Posts: 5
Joined: Tue Feb 05, 2013 7:21 am

Re: 490HZ ESC really ought to change

Post by octopus »

Who else has noticed that timecop didnt comprehend the original post?

timecop
Posts: 1880
Joined: Fri Sep 02, 2011 4:48 pm

Re: 490HZ ESC really ought to change

Post by timecop »

Since RC PWM pulse width is from 1ms to 2ms, this allows up to 500Hz period. Any ESC claiming to be "for multicopters" must accept this.
Since the garbage you linked does not, feel free to return it and upgrade to some DJI ESCs.

FYI, on 32bit hardware (since you posted in this subforum for some fucked up reason instead of main multiwii one), esc refresh rate is configurable from 100Hz to 500Hz (or could be higher really, with minimum changes) in increments of 1Hz.

nicog
Posts: 88
Joined: Tue Aug 21, 2012 2:21 pm

Re: 490HZ ESC really ought to change

Post by nicog »

Paul, I think the one that don't comprehend is you, you claim that those hobbywing esc work perfect at 400Hz but not at 490.
How do you know? Do you have a proof of that?
In the sticker it's not told they are good at 400Hz neither the description.

octopus
Posts: 5
Joined: Tue Feb 05, 2013 7:21 am

Re: 490HZ ESC really ought to change

Post by octopus »

What do you even think my initial concern was?

timecop
Posts: 1880
Joined: Fri Sep 02, 2011 4:48 pm

Re: 490HZ ESC really ought to change

Post by timecop »

Your concern was the cheap trash esc you bought chokes when its fed with PWM period > 400Hz.
Solution: sell it and get simonk-compatible stuff and flash it yourself.
You might even learn something in the process.

octopus
Posts: 5
Joined: Tue Feb 05, 2013 7:21 am

Re: 490HZ ESC really ought to change

Post by octopus »

timecop you have a bad attitude.

Try googling "multiwii 400Hz output". there are lots of people who have raised these concerns on other forums and I have seen none of them who've had to put up with such a piss poor attitude as yours. You seriously are a sad human being. Well I'm done here. Obviously this forum is sub standard.

nicog
Posts: 88
Joined: Tue Aug 21, 2012 2:21 pm

Re: 490HZ ESC really ought to change

Post by nicog »

maybe you are not in the right section of the forum.

You know what 32bits stands for?

timecop
Posts: 1880
Joined: Fri Sep 02, 2011 4:48 pm

Re: 490HZ ESC really ought to change

Post by timecop »

The only people voicing "concern" over this are those who are uninformed, much like you are.

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Crashpilot1000
Posts: 631
Joined: Tue Apr 03, 2012 7:38 pm

Re: 490HZ ESC really ought to change

Post by Crashpilot1000 »

Hi!
First of all this is the 32 Bit section dealing with 32 Bit port of mwii etc... Having said that, with Baseflight you can adjust PWM frequ to your likings.
Referring to your skywalker20A:

I own these and they work with 490HZ pwm on my APM. They are not pure shit, like TC suggested, but they fly a little bit sluggish. The original Skywalker20A use the sil chip. Currently there are clones of them distributed using atmel chips. Both orig/clone can be flashed. The clone work with simonk tgy.hex. The original SIL chip variant was problematic with blheli but that is now fixed with this FW (bottom): http://www.rcgroups.com/forums/showthre ... 98&page=30. So reflash them and be happy.

Kraut Rob

User avatar
Plüschi
Posts: 433
Joined: Thu Feb 21, 2013 6:09 am

Re: 490HZ ESC really ought to change

Post by Plüschi »

On mega2560 boards it is quite simple to adjust esc rate to 400hz or lower.
in output.cpp go to initOutput() in the MEGA part an change all the

Code: Select all

ICR3   = 0x3FFF; // TOP to 16383; 
and the

Code: Select all

ICR4   = 0x3FFF; // TOP to 16383; 

to

Code: Select all

#define ESCREFR 0x4e65
ICR3   =  ESCREFR;
and the

Code: Select all

ICR4   = ESCREFR; 


For the 32u4 you will have to settle on 245hz. The 10bit counters need the prescaler adusted *2.

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