UDOO Smart Theremin

Lately we've been getting more and more interested in multimedia art production, and have been exploring UDOO’s interactive capabilities with lots of interesting people.

What we are showing you today is the result of this exploration project. For those of you who haven’t already seen that, we developed some time ago a simple Theremin emulator, using PureData in conjunction with a IR Ping Sensor. Since we liked a lot the idea, we then focused on it and we just came out with an improved version.
Instead of using IR Ping, we just switched the main sensor with an SRF05 Ultra-Sonic Ranger. This lead to a huge improvements in terms of accuracy, stability over time and range capability.

We then changed the Arduino sketch accordingly, in order to use this new sensor and finally we totally rebuilt the PureData patch, with tons of new functionalities. Here is a quote from Roberto Nannetti, the mastermind behind Smart Theremin.

We add some patches for more musical interesting and experiences, like jam with your favorite tunes. Now you can improvise with your simple hands moves on blues, a jazz tune or on a famous rock riff. A player was added that let you choose your favorite music from your musical archive. You can play, stop, restart or loop your samples as you need. A list of scales is now avalaible: you can choose between major scales and all derivative modes (Dorian, Phrygian, Lydian, Mixolydian, Aeolian, Locrian), jazz minor scales or blues scales in the key that you need. The basic sound is now reinforced by some fx like a three voices overtone and a reverb.

The Smart Theremin is now  a real instrument for improvising alone or in a combo with others musicians.

Last but not least, we just had a proper, and extremely talented musicia, Irene to show the Smart Theremin musical vocation.

Let’s see how to get the smart theremin working:

WIRING

Just connect the SRF05 Ultra-Sonic Ranger to UDOO as follows:

5V -> 5V
ECHO -> PIN 2
TRIGGER -> PIN 3
GND -> GND

Then compile and upload the following Arduino Sketch:

//SRF05//
#define ECHOPIN 2  // Pin to receive echo pulse
#define TRIGPIN 3  // Pin to send trigger pulse


int msg = 0;

void setup(){
  Serial.begin(9600);
  pinMode(ECHOPIN, INPUT);
  pinMode(TRIGPIN, OUTPUT);
}

void loop(){
  digitalWrite(TRIGPIN, LOW);                   // Set the trigger pin to low for 2uS
  delayMicroseconds(2);
  digitalWrite(TRIGPIN, HIGH);                  // Send a 10uS high to trigger ranging
  delayMicroseconds(10);
  digitalWrite(TRIGPIN, LOW);                   // Send pin low again
  int distance = pulseIn(ECHOPIN, HIGH);        // Read in times pulse
  // distance= distance/58;                        // Calculate distance from time of pulse                 
  if(distance > 4100)
    distance = 4100;
  if(distance < 200)
    distance = 200;
  msg = map(distance, 200, 4100, 0, 255);
  Serial.write(msg);                     
  delay(10);                                    // Wait 10mS before next ranging
}

Now, you’re ready to launch PureData and load the Smart Theremin patch and enjoy real-time improvisation with UDOO!

As usual, you can find the complete source code on UDOO Projects Github: