how to calibrate the raw sensors?

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TJ-Shredder
Posts: 22
Joined: Fri Aug 12, 2011 2:51 pm

how to calibrate the raw sensors?

Postby TJ-Shredder » Wed Sep 07, 2011 12:26 am

Playing with the SoftStep is kind of fun now, but the 44 controllers are very different in their sensitivity. I wonder if there is a way to calibrate them. I could do that within Max, but then I would loose resolution. And especially the point where the navigation sensors jump in is way, way higher than with the other sensors. With Max alone I would never be able to adjust that entry point...

If its not possible yet this is a strong feature request...

Stefan
DaveDraper
Posts: 64
Joined: Fri Feb 25, 2011 9:10 am

Re: how to calibrate the raw sensors?

Postby DaveDraper » Sun Apr 29, 2012 3:28 am

I just got my replacement SS after the USB socket broke, & yesterday when trying it out noticed one particular sensor not responding even when practically standing on it. Remembering this post, I did a vaguely scientific test today, of standing a heavy block of steel on each pad in turn (I've got four little plastic buttons on each of mine) and noting the raw CC data in MIDI Monitor. I am a bit shocked at the variation, from values in the 50s & 60s for some pads (particularly 1-5), and single figures for others (esp 6-0). The Navpad buttons seem less responsive than the old SS, but I never noticed, or measured, such a variation before. I realise the exact position of the plastic buttons, & the weighty lump of steel will affect the results, but there's a certain consistency in them nevertheless.
This is all raw CC data, nothing running on my macbook other than Midimon. Don't know if the unit has anything on board to alter the response of individual sensors - it's a bit of a black box.
I'm using a Bidule group to control mine, so I guess I'll have to look into individual sensitivity tweaking for each sensor :(
Dave Draper
Peter Ostry
Posts: 23
Joined: Fri Jul 22, 2011 1:56 pm

Re: how to calibrate the raw sensors?

Postby Peter Ostry » Tue May 01, 2012 10:40 am

I gave up manual calibration and made a "learn" function in Max instead. Basically with the [maximum] and [scale] objects. I switch calibration on and step on all corners. This sets the scale factors for each corner in my input section and I get always 0-127.

On stage I calibrate always before I play, with the shoes I will use during the performance and standing (sitting) in playing position.

---

Regarding resolution – of course we don't get precise 0-127 events from the SoftStep. It's not a pedal, it's just a bunch of plastic pads. The Softstep is advertised as a pedal replacement but I hope nobody expects the same precision for 1 mm working range as he can get from 60 mm (or more) from a mechanical pedal.

I use the direct values very rarely because they are so coarse. For fading tasks I've programmed autofade functions, optionally pressure-sensitive.
DaveDraper
Posts: 64
Joined: Fri Feb 25, 2011 9:10 am

Re: how to calibrate the raw sensors?

Postby DaveDraper » Tue May 01, 2012 11:27 am

Impressive 'on stage' calibration there.....
I just had a thought (ahhh, don't think!!) about a sort of absolute calibration, that involved one of those adjustable G-clamp type automobile valve-spring compressors (are you still with me here?), which one might use to compress each pad to a (roughly) equal force (using appropriate padding in the form of wooden blocks, perhaps) in turn, so that one might be able to set sensitivity functions to approximate an equal response in the software.
One might be able to extract some consistent & useful data by this means, & even apply it to the proprietory software, but I can't help wondering why should this be necessary?
Dave
Peter Ostry
Posts: 23
Joined: Fri Jul 22, 2011 1:56 pm

Re: how to calibrate the raw sensors?

Postby Peter Ostry » Tue May 01, 2012 1:33 pm

DaveDraper wrote:... sort of absolute calibration, that involved one of those adjustable G-clamp type automobile valve-spring compressors ...

Oh My God. :-)
Or maybe Keith can integrate 44 tiny letter scales into the Softstep?

Better use a real pedal for the real continuous stuff. 2 mm plastic squeezed to 1 mm isn't a precision instrument. Maybe such a material exists, but I guess we would not want to pay for it.
DaveDraper
Posts: 64
Joined: Fri Feb 25, 2011 9:10 am

Re: how to calibrate the raw sensors?

Postby DaveDraper » Wed May 02, 2012 6:42 am

DaveDraper wrote:... sort of absolute calibration, that involved one of those adjustable G-clamp type automobile valve-spring compressors ...


Oh My God. :-)

Bloody improvisors!! :)

Dave

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