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Swell shutter control on real pipe organ


sd2000
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Hello all

This question is about swell shutters on a real pipe organ.

The instrument was originally controlled by a paper roll player and I am using MIDIIO128 to control the notes and stops, that’s all fine, it plays and changes rank.

But it would be really good if everything could be controlled via MIDI. 

The shutter is a six step affair, so there are six stages to get a get a fully open shutter.

My idea is to use Channel Volume, B0 07 xx, to open and close the shutters.  So what I would like to do is to have six pins on the DOUT respond to say:

B0 07 02

B0 07 08

B0 07 0F

B0 07 20

B0 07 40

B0 07 7F

And only these values, these are just example values and if at all possible, they could be changed via the MIDIIO128.ini file just as the other pins are.

From what I can tell, the B0 xx function only responds to either 00 or 7F.

Anyone got any ideas?

Thanks and regards

SD

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  • 2 weeks later...

There is a lot of discussion about this at:

\http://www.virtualorgan.com/forum/forum_posts.asp?TID=165

There is information on how to specially modify the core syx file to allow the use of up to 8x (I think) analogue inputs.

Your question may be just asking if you can use six digital ins to give your required signals.  I think this is possible, but the analogue custom addition may also be of interest to you.

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Thanks for the reply.  I think you may have misunderstood.  I am using a real pipe organ, its a MIDIO128 but only using the DOUTs!  There are no DINs or AINs, only a MIDI In and 128 DOUTs.

What I am after is for the commands above to activate the relevent DOUT pin.

Anyone?

Thanks once again.

SD

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hi sd2000

it appears that your problem is that you are activating the DOUT pins on discrete volume levels from midi.

the problem is that the volume signal probably will use other values in the volume messages.  therefore you need to configure your system to activate the appropriate pin on its range of volume levels.  i believe hand coding which DOUT to activate for each of the 128 volume levels can be done. (if there is an easier way, can someone who knows midio128 better than myself explain it)

btw the signal levels you are providing for each DOUT appear to be on a logarithmic scale, it might be a good idea to check the pot attached to your expression pedal and make sure it is a linear pot and not a logarithmic pot. (i don't know how to tell the difference, but it should be available with a google search)

on a linear scale, an even distribution would be:

[table][tr][td]DOUT[/td][td]Hex[/td][td]Dec[/td][/tr][tr][td]1[/td][td]0-15[/td][td]0-21[/td][/tr][tr][td]2[/td][td]16-2A[/td][td]22-42[/td][/tr][tr][td]3[/td][td]2B-40[/td][td]43-64[/td][/tr][tr][td]4[/td][td]41-55[/td][td]65-85[/td][/tr][tr][td]5[/td][td]56-6A[/td][td]86-106[/td][/tr][tr][td]6[/td][td]6B-127[/td][td]107-127[/td][/tr][/table]

of course this assumes that your minimum and maximum volume signals from your hardware are 0 and 0x7F(127) respectively.

now once you get the system working, there is no reason not to adjust the values for reasons of comfort, ascetics or placing the transition points at the same places as the orignal organ.  just take care not to have any overlaps (which would power more than one of the DOUT) or gaps (which would have none of the DOUTs powered).

best of luck

OrganGrinder

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Hi,

I think I understand what you are looking for. The DOUT is responing to Channel volume as follows:

B0 07 00 -> set pin to 0V

B0 07 xx where xx is 01-7F -> set pin to 5 V.

In your example all six pins will be turned on by any of the B0 07 since the third byte is in the range of 01-7F.

You could use six different Control Change commands instead. There are several not assigned to any specific function.

B0 0C 00

B0 0D 00

B0 0E 00

B0 0F 00

B0 10 00

B0 11 00

If the third byte is different from 00 the pin will be set to 5 V, if 00 set to 0V

Regards,

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  • 3 weeks later...

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