Hi,
today we learn how to build a simple EWI (Electronical Wind Instrument) from the parts shown in the video. The main part and a basic arduino sketch can be found here ->

http://www.hobbytronics.co.uk/yf-s201-water-flow-meter

for german user, buy it for about 5 Euro in your prefered online shop. Search  for  „Wasserdurchfluss Sensor Durchflussmesser“ or something similar.

So you can take off in a minute. On that website is described how to connect the three wires to your arduino:

Connection details:

Red wire : +5V
Black wire : GND
Yellow wire : PWM output.
It is simply a YF-S201 Hall Effect Water Flow Meter / Sensor. Originally used for measuring the amount of water that flows through it you can simply attach a small flexible sprinkler hose to it and use it as a wind controller, a so called EWI.

Just upload the sketch from your Arduino IDE, change the baudrate
from    Serial.begin(9600);
to      Serial.begin(38400);
and you are done!
Open the serial monitor. Set the baudrate from 9600 to 38400 and blow or suck the air into or from the tube and see how the values change.
Use these values in your midi software for the arduino to change pitchbend, octaves or anything else that a midi control message is able to change!
Have fun.

p.s.: yes, I know that „soap spender“ is a soap dispenser, a „Durchfluss Sensor“ is a water flow meter and a „Gummidichtung“  is a rubber gasket 😉