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Old Nov 02, 2011, 05:20 PM
Tri-Quad-Hexa-Octo-copters!!
United States, TX, San Antonio
Joined Feb 2007
14,408 Posts
Hi Simon,
They are not quite an insect, but the Astec quads that you see performing those amazing stunts are commercial variants of the XBL that was stated to have a 1khz ESC/FCB update rate. Widelec put together a thread that has most of those videos: http://www.rcgroups.com/forums/showthread.php?t=1530432
The MK with Holger BLC's is stated to have ~500hz update rate. The OEM HobbyWing and variants have been measured from 250-350hz update rate. And your Quax/SimonK fast PWM ATMEL firmware is stated to ~500hz update rate.
It has been interesting to follow all the other improvements that you Gents are finding to make these ESC's work well with multicopters.

Keep up the great work!
Cheers,
Jim
Quadrocopter and Tricopter Mega Link Index

Quote:
Originally Posted by simonk View Post
As quax has been recommending for people using his tree with multicopters, there is no averaging or change limit. It just sets the duty to the minimum of the requested amount and the calculated safe limit for the sensed timing.

A shorter pulse will reduce lag if you are using an i2c converter unless the i2c converter has some sort of PLL and starts the pulse early, since you're directly reducing the time that the i2c converter gets the i2c command and the generated pulse goes low. However, that's only saving around 1ms, and with an update rate of 500Hz, it's already updating every 2ms. Getting rid of that 1ms might be similar to increasing the update rate from 500Hz to 1kHz, which should really only make a difference if you're flying an insect...
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Old Nov 02, 2011, 05:23 PM
Registered User
France
Joined Nov 2003
278 Posts
@jesolins
I made changes in a previous version of simonk code. Retrofiting them to earlier one should provide something like:
Code:
.equ	START_RC_PULS	= 200	; 
.equ	FULL_RC_PULS	= 200 + 512	; POWER_RANGE = 512
.equ	MAX_RC_PULS	= FULL_RC_PULS + 100
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Old Nov 02, 2011, 11:45 PM
hacker
Canada, BC, North Vancouver
Joined Dec 2010
934 Posts
Quote:
Originally Posted by bas10an View Post
I found a possible candidate for the custom FW:

Mystery red 10A ESC

Mystery red 20A ESC

Atmel brains and programming pads.

They come in many sizes from 10A to 120A

Someone should give them a try, not me - I've spent all my allowance.
The 20A version is identical to the board I received when I ordered http://www.hobbyking.com/hobbyking/s...dProduct=15205 (30A) -- they had >1000 in stock when I did, then suddenly they were backordered, so it might be something completely different now. It's a pretty good board, except that it does tend to reset easily if overcurrented. In fact, if I touch my scope probe to the reset pad, it resets. I added some MCUCSR register checking on boot to see which reset source it was, and it was the brown-out detector. I turned off the brown-out detection, and then it was just a power-on reset. But if I touch the scope probe, it's a reset line reset. Hehe...

Anyway, if not driving too high a current (>~18A), it's pretty good. Mine is mystery nfet (bs_nfet) pinout, with the inverted drive high side nfets. Here are some close-ups of mine (the one I got from Hobbyking, not dealextreme):
http://0x.ca/sim/tmp/hk_30a_esc/
Same pinout as http://www.rcgroups.com/forums/showthread.php?t=1401408 and thus http://tfsoft.org.ua/tmp/el/AVR/hk_b...series_30a.png
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Last edited by simonk; Nov 03, 2011 at 12:13 AM.
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Old Nov 03, 2011, 12:01 AM
hacker
Canada, BC, North Vancouver
Joined Dec 2010
934 Posts
Quote:
Originally Posted by obor View Post
.equ START_RC_PULS = 200 ;
.equ FULL_RC_PULS = 200 + 512 ; POWER_RANGE = 512
.equ MAX_RC_PULS = FULL_RC_PULS + 100
[/code]
Heh, that's what I get for trying to simplify the configuration. Now you're reversing the math to make it make sense again. Don't worry, I'm overhauling it again so there is even less chance it will make sense.

POWER_RANGE at 512 gives a pretty fast PWM frequency of about 29kHz. That's well above audible. The usual 800 gives 19kHz, 1000 gives 15.3kHz (sounds nasty, headache inducing to me). There's nothing wrong with a higher rate, but it may heat up the FETs more. I was planning on going with *3 (POWER_RANGE 768) for 8-bit twi/i2c input.
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Old Nov 03, 2011, 10:32 AM
RC beginner
New York
Joined Oct 2008
5,963 Posts
im being told new turnigy 6a is not avr anymore (and draws .6a when idle!). does anyone know of another similar esc that weighs less than 6 grams and can be flashed?
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Old Nov 04, 2011, 11:46 AM
Jakub J's Avatar
Krakow/POLAND
Joined Dec 2009
1,701 Posts
Quote:
Originally Posted by timecop View Post
You know that's funny.
I blew up my Rc timer 10a as well.
I thought I did something wrong.
Symptom was similar... The motor barely spin and smokey.
Exactly like my 3pcs of 10A Rctimer... 40A cureent, smoke from wires,
motors etc. Just crap.

I have a lot Tower Pro 12A ESCs - is't this firmware compatible
with this ESCs?

jakub
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Old Nov 04, 2011, 06:03 PM
hacker
Canada, BC, North Vancouver
Joined Dec 2010
934 Posts
Quote:
Originally Posted by Jakub J View Post
Exactly like my 3pcs of 10A Rctimer... 40A cureent, smoke from wires,
motors etc. Just crap.

I have a lot Tower Pro 12A ESCs - is't this firmware compatible
with this ESCs?

jakub
Hi, Jakub! I don't have any RCTimer or TowerPro ESCs to test with, but I think it should work. Depending on the age, they are probably one of the usual TowerPro type1 ("tp.inc"), type 2 ("tgy.inc"), or type 3 ("tp_nfet.inc") pinouts. You just have to select the right one when building. I would check to see what kind of FETs are on one side and do some simple continuity tests or trace-tracing to see which pinout it looks like. I keep accidentally flashing tgy to mystery boards, etc., and still haven't managed to fry anything that way. If you don't hear three beeps when it starts, one or more of the FETs are dead, or the pinout/build is wrong.

We never got to the bottom of what happened with the RCTimer 10A boards. When you said they smoked, was that just booting up, or after they already worked for some time, or what? It'd be nice to know what was going on there, and if it was just a pinout error or something, maybe we could add protection to prevent that from happening again. For example, I was looking at Mystery schematics to try to find some crafty way of making VCC more stable, and noticed that they always seem to have PC2 pulled up (divided input voltage), PC1 pulled up to VCC with some weird diode up from ground, and PB2 tied to ground. That could pretty easily be used as a way of detecting those boards, and stopping before any damage, etc., happens, or just autoconfigure the dang thing and make one build work on all boards. (It's not that far off, actually, with memory-mapped I/O being used for nFET switching already.)

Btw, the latest push has motor reverse support and optional RC-car style reverse throttle support. It's not good enough yet to flip direction while flying because the starting kind of sucks while the motor is spinning the wrong way, but it's not bad with 2213N motors (about 100-150ms to switch from full throttle one way to the other way, with no propeller). Probably need to brake until stop is detected and then restart quickly. The current code just tries to drive the current timing backwards, which does brake without regeneration, but it loses timing before stopping and thus still futzes around for too long with some motors.
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Old Nov 06, 2011, 03:33 PM
Registered User
Canada, AB, Calgary
Joined Sep 2011
328 Posts
It looks like the RCTimer Programmable ESC 40A V2 will work. I'm waiting for some connectors to test it, but the unit seemed to flash fine using my old STK500 programmer.
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Old Nov 06, 2011, 11:15 PM
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Joined Dec 2005
676 Posts
Can these be flashed?
http://www.rctimer.com/index.php?gOo...1&productname=
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Old Nov 07, 2011, 02:31 AM
Registered User
Joined Sep 2011
327 Posts
Hi guys,
I got some weird brand Dragon ESCs 30A with the atmega8a chip on it. Would it work? My multimeter is on its way so I cant test yet but I guess the 6 copper pads are the one I need to hook up to the ARV usb. Thanks.
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Old Nov 07, 2011, 02:53 AM
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Joined Dec 2010
11,764 Posts
I think dragonsky uses the standard tgy pinout, and some might even have firmware unlocked incase you want to go back to it. Without multimeter its hard to say, but yes, those pads are likely for programming. You'd have to reference to the datasheet and check which pins they connect to. You might still need 5V.
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Old Nov 07, 2011, 06:53 AM
zis
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Joined Mar 2009
8 Posts
who programmed TowerPro 25A Rev. H 2009-09?
how to install the fuses for tgy-2011-10-12.hex?
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Old Nov 07, 2011, 06:56 AM
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fuses: intrc, the rest = common sense.
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Old Nov 07, 2011, 08:04 AM
Registered User
Joined Sep 2011
327 Posts
Quote:
Originally Posted by timecop View Post
I think dragonsky uses the standard tgy pinout, and some might even have firmware unlocked incase you want to go back to it. Without multimeter its hard to say, but yes, those pads are likely for programming. You'd have to reference to the datasheet and check which pins they connect to. You might still need 5V.
Thanks TC. Is it really Dragonsky? I got these from Thailand and it only says"Dragon 30A Economy" on the label. What do you mean by might need 5 V? I was under the impression that the ESC is powered by the AVR usb programmer. If I was wrong then how do I power it?
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Old Nov 07, 2011, 08:09 AM
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Ah, well who knows then. It could be a clone of mystery blue, some of them have pads in odd places like that. Without a meter its going to be fairly difficult to tell. Also looking at the FETs on the back could be helpful - whether its all-N or P/N design. I think this firmware supports only one variant of all-N, the mystery blue + clones.
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