MIDI concertina III: the load cell version

[caj]

Inspired by Danny's Bandon.ino project, I decided to build another MIDI concertina using a 1kg load cell for the bellows sensor.  Here's my first video:

 

 

 

I used two simple 3d-printed attachments to hold the load cell in the center, and I can easily read press or draw forces on it with the HX711 that came with it.  The rest is the same buttons/lights/chassis/teensy/etc.  

 

It's a slightly different experience with the ends not moving at all, and perhaps easier to play quickly and precisely.  I still have to adjust the programming to account for the new sensor's sensitivity.  By the way, it has a huge dynamic range that doesn't come through in the video --- I think my camera applied some dynamic compression so you can't hear how loud/quiet it gets.

Edited August 1 by caj
Fixed the video

[SIMON GABRIELOW]

Rather unusual .. a sort experimental other world ..

Like the old film says..

"I made it with my own hands, my own hands"🌝

[b13]

Very exciting. Would you make a link to "Danny's Bandon.ino project"? I also thougt over these things, but i am not able, to realize it from the tec-side.

 

[caj]

24 minutes ago, b13 said:

Very exciting. Would you make a link to "Danny's Bandon.ino project"? I also thougt over these things, but i am not able, to realize it from the tec-side.

 

 

He's posted about it here, and you can find details on page 3 of this thread.

 

That inspired me to try using a load cell as well.    My impression is that it makes much more sense for something like a MIDI concertina kit, because it's self-contained and widely available.  My previous attempt at a sensor was homebrewed and required a bit of assembly, with more moving parts that made it complicated to install (and noisy.)  The load cell has no moving parts and obviously makes no noise at all.

[caj]

Here's another attempt to convey the box's dynamic range:  I shunted the audio straight from Mainstage to Blackhole and from Blackhole to OBS, and I think it works better to show how it sounds.

 

 

It's actually way more effective when I plug the laptop into an external speaker, in which case I can really make the thing go from meek to blasty.  

[Howard Mitchell]

It’s almost a year since I produced this prototype midi anglo using a load cell. https://youtu.be/pAvdKVcUVAs?si=t4ezH3S3_pk4fxvk

 

it needs more work on the algorithm to relate force to midi polyphonic pressure. 

[Richard Mellish]

12 hours ago, Howard Mitchell said:

It’s almost a year since I produced this prototype midi anglo using a load cell. https://youtu.be/pAvdKVcUVAs?si=t4ezH3S3_pk4fxvk

 

it needs more work on the algorithm to relate force to midi polyphonic pressure. 

That would be difficult wIth my system, which sends an analogue control voltage to an off-the-shelf MIDI controller; but if you have a microprocessor doing the clever stuff a simple look-up table should do the job.

[caj]

21 hours ago, Howard Mitchell said:

it needs more work on the algorithm to relate force to midi polyphonic pressure. 

 

May I ask what the exact problem is?  From the video, it already sounds incredibly responsive.

 

I had a problem where I wanted dynamics with quiet notes from gentle pressure, but I also wanted the notes to sound quickly and firmly without ramping up in volume when I played normally.  Right now I'm addressing that by taking the force input and squashing the low end, so that it goes from 0 to medium loud faster while still allowing me to play quietly.