A midi trumpet

I'm planning to create a midi trumpet. If it works, I will expand the idea to a midi trombone.

I picked some components from an old matrix printer. Among the stuff there was a piece of PCB holding the three push buttons of the front panel. So I thought of turning it into a trumpet. I just received a pressure sensor, which I'll use. I'm going to create midi events that I send to an old midi synthesizer through a standard midi cable (with DIN connectors). My idea is to attache a tube to the sensor. I'll be blowing in the tube. I might want to make holes in the tube to adjust the amount of pressure that reaches the sensor. And I want the feel of actually blowing, not just pressing air. A certain threshold will create a midi note-on event (or is it called key-down?). First the pressure will determin a pitch, or a frequency. Then I will read the three buttons. I will calculate the nearest tone to this key combination. This tone will be the one that the note-on event will play. I will also create a pitch-bend event to match how much off the pitch the pressure is. And as long as there's a pressure over the threshold, the sound will continue. My controller will read the pressure continuously and create pitch-bend events accordingly. When the button combination changes, a note-off event is created and a new note-on event is prepared and performed. When there's a sound on and the pressure changes enough to activate another tone, a note-off event happens and a new note-on is prepared.

So far I've just planned to have the tube I'll be blowing in. This is far from the real feel of playing a brass instrument! But I'm hoping anyway to create a feeling remotely resembling the playing of a three valve brass instrument. And a synth with a trumpet-like sound will add to the illusion. But I might develop the idea to include a real mouth piece to blow in.

And if it works, I'll continue with a trombone. I'll use electric installation tubes for the slide, a light source (bright white led) and a light depending resistor to measure the slide position. The nature of a trombone requires a greater pitch bend range. Moving the slide while the tone is on only affects the pitch-bend, whereas pushing the buttons on the trumpet creates new note-on events.

Perhaps would you look at sites about wind controllers, such as Patchman's to see existing EVI (Electric Valve Instrument) implementation.
It will give some more ideas to build your own.
Electric trombone I've read about don't use a light system but a ribon and a potentiometer to read the position of the slide.

I'm fond of the light idea, because it needs not much. Just a led and a battery in one end, plus a resistor maybe. And the light dependent resistor in the other end. Though I don't know how accurate it will be. A potentiometer ribbon would need to be some 40 cm long.

I just found two plastic tubes of different sizes, which almost perfectly slide into each other. I suppose I have to paint them with matte black. The larger one on outside and the smaller one on inside.