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Mar 15, 2017, 04:09 PM
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Quote:
Originally Posted by OlliW
adding poti this should be quite simple to do
Do potis work well as encoders ? Really ?
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Mar 17, 2017, 05:11 AM
Registered User
Do you use mpu-9250 raw data or DMP?
Mar 18, 2017, 01:47 AM
OlliW
Thread OP
@fs008: no idea, but you find applications there they are used such (one of them being Alexmos )
@alvedro: not DMP
Mar 23, 2017, 03:09 AM
OlliW
Thread OP
for your info

* firmware released
see https://www.rcgroups.com/forums/show...postcount=9557

* wiki
some documentation done:
What is T-STorM32 about?
Getting Started with T-STorM32

* NT motor modules v2.3E
I do have another 3 NT motor modules v2.3E available, for 20Eur each + shipping
fully assembled, tested, flashed, but no wires, no magets etc.

Mar 24, 2017, 03:28 PM
Registered User
Quote:
Originally Posted by OlliW
I must admit that I'm jealous at the Basecam Tiny revB ... this is really designed by experts who know what they do ... way beyond my capabilties..
Hi OlliW,

May I ask in what regard is the above statement ?

Software, hardware-wise or PCB ?

If the answer is around the last two, some options can be explored. I was still working on my DIY NT boards (there is a post in that thread ) and was a bit sad to see new concept out (meaning non-encoder NT boards could be soon put into EOL state) , but depending on the requirements some help may be arranged. To be honest I did not read the entire thread, just the initial posts for the new system.

Regards
Mar 24, 2017, 03:44 PM
OlliW
Thread OP
hey potrebitel

hardware-wise and pcb-wise

my designs lack from the fact that I never have attempted a switching regulator, and from being limited to two layers only ... and maybe also from my limited routing skills
the design, hardware and pcb-wise, of the tiny revB I find amazing

I'm not sure one would consider non-encoder NT motor boards EOL ... adding the encoders adds a range of mechanical challenges to a design, especially for DIY ...
looking at your skills however that's probably not an issue to you
Mar 25, 2017, 12:11 PM
Registered User
hey OlliW,

I haven't found a reasonable 4 layer PCB service for small projects. The one around me is 2 layers with 8mils/8mils ( but questionable quality under 10mils ) and 0.5mm drill holes. It is cheap, but still not the best quality. Otherwise it is very tempting to try 4 layer PCB since speed-wise almost any routing will do the trick for such designs (at least my experience ).
There is one called seedstudio, but they make sense only for several boards ( 10 pieces 100x100 mm panels are $60 ),i.e. the yield of 40x20mm board will be alot for a single person.

I am saying that since I can try 4 layer PCB for STorM32 modules ( mainboard,NT, etc ), but trying them out will be a challenge for me alone at that stage ( have lots of expenses to cover ).
1mm thick 4 layer PCB with 6mils/6mils, 0.4mm drills and 0402 will be quite interesting to try.

Regards
Mar 25, 2017, 12:29 PM
OlliW
Thread OP
for small-number prototypes I started to use oshpark a lot, they also provide 4 layers, it is not most cheap, but still quite OK, and I really like their upload procedure a lot

I also used to use smart-prototyping a lot, which I still use occasionally when more pcbs are wanted, they also offer 4 layers

both services I consider reasonable

yes, pcb developing can drain the vallet
Mar 26, 2017, 11:35 AM
OlliW
Thread OP
for that build the concept of separate motor-encoder modules might appear more logical:

I've modded my old mobius-carbon-hitec gimbal for working with T-StorM32. The build doesn't make much sense, too much weight for an outdated camera, but I had that gimbal around, so, why not.

Interestingly, I observed the same tendency as for my "bigger" handheld gimbal, namely that the control accuracy is significantly better with encoders, see also post https://www.rcgroups.com/forums/show...9&postcount=30. If that better accuracy would be there also at higher frequencies, above 30Hz, then this encoder thing could really be a deal-breaker for aerial applications. We will have to see.
Mar 26, 2017, 01:42 PM
Registered User

Sigh


My gimbal is actually working flawlessly now but I still feel like I need encoders badly. This is probably not a rational feeling....Not sure what to do!

Are you seeing the expected big reduction in battery draw?
Mar 27, 2017, 07:48 AM
Registered User
Hi OlliW,

What is the airgap between the Magnet and PCB in your working T-STorM32?
What is the diameter of your Magnet?

I am using the 2804 size motor.
After checking some stuff it seems I need to choose a Magnet larger than 10mm diameter.
But I am not have any idea about the airgap limitation range.

One more thing is the Magnetic field direction of the Magnet also need to consider about?
I found some Magnet with same shape but it's not this type of Magnetic field direction.
Mar 27, 2017, 08:49 AM
OlliW
Thread OP
you need diametrically magnetized magnets, as in your picture, axial (which are more common) won't work

the airgap depends on the magnet, both size and strength
the TLE encoder allows for quite some variation in the magnet strength and hence airgap, with my magnets it can be anything from few mm to some mm (have never tested that explicitly)
however, I noted that when the airgap gets small some non-linearities do appear. I think that this is because of misalignment or imperfect centering of the encoder chip in relation to the magnet, it seems plausible to me that these deviations become the more relevant the closer the encoder is to the magnet and/or the smaller the magnet is

in short, I think you will have to experiment

btw: the hollow shaft 2804 motor I found very convenient, since it's bell shaft has a diameter of 7 mm, which is exactly the inner diameter of my ringmagnets, that is, with these motors I just had to put the magnet on the motor, and done (if you inspect the video/pictures of the pitch motor on my stick gimbal you may see that)
Mar 27, 2017, 09:17 AM
Registered User
Quote:
Originally Posted by OlliW
you need diametrically magnetized magnets, as in your picture, axial (which are more common) won't work

the airgap depends on the magnet, both size and strength
the TLE encoder allows for quite some variation in the magnet strength and hence airgap, with my magnets it can be anything from few mm to some mm (have never tested that explicitly)
however, I noted that when the airgap gets small some non-linearities do appear. I think that this is because of misalignment or imperfect centering of the encoder chip in relation to the magnet, it seems plausible to me that these deviations become the more relevant the closer the encoder is to the magnet and/or the smaller the magnet is

in short, I think you will have to experiment

btw: the hollow shaft 2804 motor I found very convenient, since it's bell shaft has a diameter of 7 mm, which is exactly the inner diameter of my ringmagnets, that is, with these motors I just had to put the magnet on the motor, and done (if you inspect the video/pictures of the pitch motor on my stick gimbal you may see that)
Thanks for your info, much help to me!

"however, I noted that when the airgap gets small some non-linearities do appear. I think that this is because of misalignment or imperfect centering of the encoder chip in relation to the magnet, it seems plausible to me that these deviations become the more relevant the closer the encoder is to the magnet and/or the smaller the magnet is"

This seems to me that may be related to Magnetic field distribution curve. The larger magnet may have flat curve even the encorder chip is close.
Mar 27, 2017, 02:52 PM
OlliW
Thread OP
@McTage:
good question
this should answer this:

T-STorM32 vs STorM32: Comparison of Current Consumption (1 min 37 sec)
Mar 27, 2017, 08:36 PM
Registered User
~60% reduction!!!!!!!!!!!!!!!!!!! My guess is that that may not be a huge deal for drones because they are drawing so much more current for flight than the gimbal but for a hand-held or wearable gimbals that is huge.


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