The Breath sensor:

The breath sensor I use is frm Freescale. There is a dual pressure sensor

on the second mouthpiece, (the plastic orange one)

Measuring my own breath I found that I could generate about 10 kPa

overpressure. It is not nice though to just give pressure and not to blow.

There is a small rubber cork in the throat of the mouthpiece. In this

cork are 4 holes (ø 3mm). 1 for the pressure sensor and 3 to give the air

room to flow. It is much harder to build up pressure now so I changed

from the MPXV7007DP to the MPXV7002DP.

You can not only blow in the sensor but you can also suck (which I

sometimes do on the real trumpet as well). I see this as two separate

controller parameters. Output values bigger than 2.5V mean blowing and

output values smaller mean sucking.