They put a Cortex M0 on the module that sits on the board, along with the
stepper driver and encoder.
There's a greater latency inside the Cortex, it will likely have to respond to
an interrupt thus have ISR latency. I presume they've got a PLL to prevent
oscillation within the final step.
It
Best option is probably to generate stepper signal from hardware timer.
2016-10-21 8:17 GMT+02:00 Danny Miller :
> The SPI comm of course has latency within a comm period.
>
> However, the pulse output must be super-fast. It supports up to 14500
> rpm, so if it's 2000steps/rev the whole step cyc
The SPI comm of course has latency within a comm period.
However, the pulse output must be super-fast. It supports up to 14500
rpm, so if it's 2000steps/rev the whole step cycle is 2ms, realistically
like maybe 1/4 of that for latency?
Danny
On 10/19/2016 11:34 PM, Nicklas Karlsson wrote:
>>>
> > ... The lag also seemed to vary with velocity.
> >
> >
> Most specifically, it was a lag in the encoder's loop to respond to
> acceleration.
> Velocity was fine, but when there is acceleration, the encoder's
> velocity didn't change for a few milliseconds, then it had to produce
> velocity g
On 10/19/2016 01:08 PM, Kirk Wallace wrote:
> On 10/19/2016 10:53 AM, andy pugh wrote:
>> On 19 October 2016 at 18:34, Roland Jollivet
>> wrote:
>>
>>> While the devices have a high resolution, look at pg.7 for all the
>>> non-linearity specs. So while you may discern 16 383 positions, you may b
On 2016-10-19 12:08, Gene Heskett wrote:
> That will give 16,383 discrete positions of
> the screw per revolution of the screw,
No, the max pulses are 1024 and the max steps are 4096. (pulses x 4)
Putting the magnet on the pointer of an old dial gauge you have a nice surface
feeler for
measuri
On 10/19/2016 10:53 AM, andy pugh wrote:
> On 19 October 2016 at 18:34, Roland Jollivet
> wrote:
>
>> While the devices have a high resolution, look at pg.7 for all the
>> non-linearity specs. So while you may discern 16 383 positions, you may be
>> well over 50 counts in error.
>
> Possibly fixa
On 19 October 2016 at 19:53, andy pugh wrote:
> On 19 October 2016 at 18:34, Roland Jollivet
> wrote:
>
> > While the devices have a high resolution, look at pg.7 for all the
> > non-linearity specs. So while you may discern 16 383 positions, you may
> be
> > well over 50 counts in error.
>
> Po
On 19 October 2016 at 18:34, Roland Jollivet wrote:
> While the devices have a high resolution, look at pg.7 for all the
> non-linearity specs. So while you may discern 16 383 positions, you may be
> well over 50 counts in error.
Possibly fixable in software. Especially with a stepper (we don't
hi Gene
While those AS devices are alluring, I think they're pretty useless as
encoders proper. It bothers me that the datasheet does not say in bold,
"About +- 1 degree accurate only!"
While the devices have a high resolution, look at pg.7 for all the
non-linearity specs. So while you may discer
I,m actually working on a unit to do exactly that Gene.
Along with tool breakage sense
Which is tending to be the pain, so I might make 2 units
Sarah
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On 19 Oct 2016, 11:13, at 11:13, Gene Heskett wrote:
>On Wednesday 19 October 2016 01:01:18 Danny Miller wrote:
>
>
On 2016-10-19 07:01, Danny Miller wrote:
> But there's no mechanical connection to the motor, it's this new AS5047D
> high speed, high resolution magnetic rotary position sensor:
>
> http://ams.com/eng/Products/Magnetic-Position-Sensors/Angle-Position-On-Axis/AS5047D
It's just austrian art of eng
On Wednesday 19 October 2016 01:01:18 Danny Miller wrote:
> A friend showed me this today, not powered up yet:
>
> https://www.kickstarter.com/projects/tropicallabs/mechaduino-powerful-
>open-source-industrial-servo-m
>
> At first I was confused, it says it's a stepper, but with an encoder,
> and
A friend showed me this today, not powered up yet:
https://www.kickstarter.com/projects/tropicallabs/mechaduino-powerful-open-source-industrial-servo-m
At first I was confused, it says it's a stepper, but with an encoder,
and lowers or disables drive current when not needed. Or you can
freewhe
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