TK.

MIDIbox KB

184 posts in this topic

TK makes an in depth comment on this issue (in ucapps, I think).

 

Although the transport is much faster (than uart MIDI) there is a lot more processing that goes on at both ends.

 

Therefore, for a simple task such as transmitting notes from a KB probably better to stick to plain old MIDI.

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Correct! MIDI is old-fashioned but still quite useful, and above all very consistent, timing-wise.

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Thanks for the fast replys!

 

Okay, than I stick to the old MIDI.

 

And: What is the smallest (in budget and dimensions) MIDI Interface with at least 4 inputs and 2 outputs? Still the midibox core or is there anything else I overlooked?

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GM5 (up to 5 ins and 5 outs) is good and simple if you can get hold of the chip/PCB (I used the small PCB by TK).

 

The LPC17 core can do 4ins and 4outs and has the option of the routing functionality (if you want that).

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Ah, you are right. 

 

Okay, I will check the fleamarket. That looks like the perfect solution.

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[edit] I was considering midifying a Yamaha CS70m keyboard but instead will use MIDIO128 [/edit]

Edited by sneakthief

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New release:

 

 

MIDIbox KB V1.014

~~~~~~~~~~~~~~~~~

 

   o added "break_is_make" option which allows to trigger a note when the break

     contact is activated (nice for playing organ style)

 

 

MIDIbox KB V1.013

~~~~~~~~~~~~~~~~~

 

   o the MIDI router forwards SysEx messages regardless if channels are filtered,

     or "All" is used. It's ensured that messages are only sent once if multiple

     router nodes forward to the same destination port.

 

   o added "make_debounced" parameter: Note Off will be played when the

     Break contact has been released, and not when the Make contact has been released.

 

   o support for MBHP_CORE_STM32F4

 

 

Best Regards, Thorsten.

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I have a question regarding the aftertouch strip.

 

Duggle told me a long time ago about how to scale an analog input. 

Now I want to know, if I still need this kind of circuit even if I use an AINSER8 / AINSER64 module. Or is it really as simple as connect one side to 0V and the other side to 5V? (maybe 10k pullup?)

 

Thanks,

Chris

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Hi, It comes down to what is the output range of the strip in relation to the input range of the Ain ( I assume 0..5v). So what is the voltage range output of the strip?

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I have a schematic here, which shows the four pins of the strip that comes from the keyboard.

 

Pin 1 goes via a resistor to GND

Pin 2 / 4 are going to 5V

Pin 3 goes via a capacitor to GND

 

The values of the resistor and the capacitor are not shown in the schematic.

 

So, the AIN should fit really well, shouldn't it? Do I need the resistor and the capacitor?

Edited by FantomXR

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I'd think that the analog output is on pin 3.

If you set up the circuit as per the schematic (with same or similar value of resistor), then what is the voltage range max to min on pin 3 when you activate the aftertouch?

What is the voltage at rest (key not pressed)? 

The voltage range that is produced will determine whether you need to scale and offset this signal. 

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I don't have the circuit set up in the moment. I can do this in the next days if necessary.

 

Do you see any problems with connecting the AINSER directly to the strip? Do you think it's too much current?

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I don't understand either of the questions, sorry.

 

If you do a quick drawing of the setup, scan it or photo it and post it here, I could comment on what you're proposing.

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Excuse me to not be clear.

I thought you mean with "schematic" the one you provided in a blog article. But you mean the schematic I have here.

The problem is, that I don't have any specs on the schematic. I just uploaded it. It looks like this:



This schematic is from an instrument this keybed is build in. I don't own the instrument (otherwise I could open it and look up the values), I just have the keybed. As I have good connections to a distributor of fatar he sends me this schematic because there are no other informations about the AT-strip available.

So, I want to connect this aftertouch strip to NG via AINSER8. I already tried to connect it via a 10k resistor. This worked! But as I'm not sure if I damage the strip in kind a way I wanted to ask here :-) Edited by FantomXR

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Ok, so the other end of C9 and R7 connect to ground?

What is the voltage that appears on pin1 when you:

(a) don't press a key?

(b) press a key and hold down hard?

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Hey Folks,

 

just a short question: Is there a support for a AINSER8 in the MIDIboxKB or is it planned to be implemented?

 

Thanks!

Chris

Edited by FantomXR

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Hi FANTOM XR

or abandoned MIDIBOX Kb.It did not fit with the software Varranger.

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MIDIboxKB has a better velocity resolution. That's why I ask.

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Which configuration capabilities do you need for a AINSER8?

If predefined CCs should be sent, it would be an easy enhancement, if more flexibility is required, more work has to be done and this has to be properly discussed (because from the past I know that sooner or later you will ask for a "very important missing feature" which contradicts with the concept and then will result into a lot of work to support a special option for you...)

 

Best Regards, Thorsten.

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Please test it at your side: http://www.ucapps.de/mios32/midibox_kb_v1_016_pre1.zip

 

   o Support for AINSER8 module
     It has to be connected to J19; chip select line RC1 will be used (set jumper J4 accordingly)
     In the AIN configuration it can be selected as pin 128..135

Best Regards, Thorsten.

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Dear Thorsten,

 

thanks for the quick answer! 

I thought, that it might be possible to enhance the KB-app with two more analog inputs, so all 8 inputs of an AINSER can be used.

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I thought, that it might be possible to enhance the KB-app with two more analog inputs, so all 8 inputs of an AINSER can be used.

 

Nobody requested this so far, the firmware was not prepared for this, and therefore it wasn't available.

(or did you find this somewhere in the documentation?)

 

However, here it is:

http://www.ucapps.de/mios32/midibox_kb_v1_016_pre2.zip

 

The 4th analog pin is called "expression pedal" and assigned to CC#11 by default (but the CC can be changed)

 

Some of your old configuration settings (especially delay values for black keys) will get lost once you upload the firmware, you've to reconfigure them.

 

Best Regards, Thorsten.

 

P.S.: I won't have the time to add new features in the next 2 months.

I will only implement urgent bugfixes in the next weeks

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Thanks for the quick change!

 

I'll check it out in the next hour ;-)

 

Of course I'd need to reconfigure the keyboard. 

Are the changes also already made in the svn? If yes I could compile my own firmware, which has the delay_slowest_black_keys integrated.

 

Thanks again!

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Hey TK,

 

it works great! Thank you very much! ;-)

 

I try to understand how the midi-ports are set. It works via a hex-number but I don't get how this hex-number gets calculated. Could you please give me a short explanation about it? This would be awesome :-)

 

All the best!

Chris

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Alright, the new version is released now:

 

MIDIbox KB V1.016
~~~~~~~~~~~~~~~~~

   o Support for AINSER8 module
     It has to be connected to J19; chip select line RC1 will be used (set jumper J4 accordingly)
     In the AIN configuration it can be selected as pin 128..135

   o added 4th AIN pin for "expression pedal" (CC#11 by default can be re-assigned).

and the documentation has been updated: http://www.ucapps.de/midibox_kb.html

 

 

I try to understand how the midi-ports are set. It works via a hex-number but I don't get how this hex-number gets calculated.

 

This was already described with some examples in the documentation (search for "midi_ports")

 

Best Regards, Thorsten.

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