loading

Making music with an X-Band radar, hmmm... wouldn't that be more fun than one person should be allowed to have? It's not that hard these days, with the right tools of course. As you can see in the image that accompanies this intro, we'll use an X-Band motion sensor by www.parallax.com. In the next step we'll see what else we need. But before we go there, listen to something that was generated with this sensor. It's in the Istrian scale, which makes it slightly haunting and mysterious:

Step 1: What Do We Need

First the hardware:

Next the software:

Step 2: Building the Electronics

We're going to connect the motion sensor to the Arduino and add a LED to it as well, to show something was detected by the motion sensor. You can leave out the whole LED part, but it's always fun when something blinks.

The Parallax motion sensor we're using has four pins, but we'll use only three of them: +5V, GND and OUT. You can leave the EN pin unconnected. The +5V pin gets its power from the Arduino, and the GND (ground) is shared with the Arduino. It helps to use the red and blue strips if your breadboard provides them. First connect +5V from the Arduino to the red strip and ground from the Arduino to the blue strip. Then you can use these several times. You can check the pictures in this step to see what we mean by that.

Be sure to connect the long leg of your LED (the positive leg or anode) to the resistor and the short leg (the negative leg or cathode) to the common ground. The 220 Ohm resistor is connected to digital pin 13.

Step 3: What It Looks Like

It now looks more or less like this. In my photo I have an Arduino ethernet shield on top of my Arduino Uno, but that doesn't matter much as the Arduino pins stay the same.

Step 4: Programming the Arduino - What Are We Going to Do

It's important to understand that our motion sensor just gives us a digital signal consisting of either a 0, if nothing is detected, or a 1 if something is inside the area that's being seen by the sensor. So there is no distance measurement or variable analog value to turn into a musical note. But we would like to have some influence over the value that comes from our Arduino that's somehow related to our movement in front of the sensor. So we will count "hits" during a small window in time and report the accumulated number of hits back as a number. The speed with which we move in front of the sensor will then have at least some relation to the number that we put onto the Arduino serial bus.

Step 5: Programming the Arduino - Code

// Radar to MIDI note.
// 10.525 GHz X-Band Motion Detector (#32213) radar by www.parallax.com.
// Arduino: 1.6.2 (Mac OS X), Board: "Arduino Uno".
// Hens Zimmerman <hz37@xs4all.nl>
// June 10, 2015.

// Constants.

const int baudRate = 9600;
const int ledPin = 13;
const int maxCounter = 1000;
const int maxMIDI = 127;
const int usLoopDelay = 50;
const int xBandPin = 8;

// Initial code to run once.

void setup() 
{
  // Assign modes to pins.
  
  pinMode(xBandPin, INPUT);
  pinMode(ledPin, OUTPUT);  

  // Start serial communication to Max 7.
  
  Serial.begin(baudRate); 
}


// Loop code to run perpetually.

void loop() 
{
  // Create a small window in time during which we will count radar hits.
  // counter variable will count the amount of hits, so reset it at the start.

  int counter;
  counter = 0;

  // Start window in time.
  
  for(int idx = 0; idx < maxCounter; ++idx)
  {
      // Read value of motion sensor.
      
      int sensorValue = digitalRead(xBandPin);
      
      // Did we get a hit? Increment the counter.
      
      if(sensorValue)
      {
        ++counter;
      }
      
      // LED shows current status of sensorValue.
      
      digitalWrite(ledPin, sensorValue ? HIGH : LOW);
      
      // A small delay keeps things tidy.
      
      delayMicroseconds(usLoopDelay);
  }
 
  // Only output to serial if some motion was detected.
 
  if(counter)
  {
    // Scale to 7 bits.
    
    char output = map(counter, 0, maxCounter, 0, maxMIDI);

    // Output the number in 7 bit range.
    
    Serial.print(output);
  }
}

Step 6: Compile and Upload

You can now compile your code and upload the resulting file to the Arduino. At this point, it should already be able to detect your motion in front of it. The red LED will blink if the motion sensor sees something. The parallax sensor is quite sensitive. In fact, it can detect your pets and see through glass. There is a potentiometer on the back of the sensor to adjust the sensitivity to your situation. A small screwdriver will let you adjust this.

Check that your LED lights up if you wave in front of the motion sensor.

Step 7: Max

I've made a patch in Max that you can use to turn the data from the motion sensor into a MIDI signal. It has two modes called "drunk" and "notes". "drunk" gives the most pleasant musical results, while "notes" sounds more random.

Basically what happens is that Max regularly polls the serial port. The incoming number is already in the MIDI range [0..127], because the Arduino code in the previous steps mapped the number to this range. The "drunk" mode uses Max' [drunk] object to semi-randomly walk through the whole range of valid MIDI note values. Although you have no influence over the direction this is going, it sounds most pleasant. I have also used the number to influence the delay between generated notes. Of course you can play around with the code to make it fit your needs.

Two important notes:

  1. Choose the right serial port in the top of the Max patch. It's the one that connects to your Arduino Uno. Only when the right serial port is selected you can check the checkbox that opens the serial port.
  2. Double click the [noteout] object on the bottom of the patch and choose "from Max 1" as your option. This will route MIDI output to a virtual MIDI device called "from Max 1", We will need this in our next step.

Here is the Max patch (copy and paste it into Max via the "New from Clipboard" menu item):

----------begin_max5_patcher----------
3168.3oc6as0baaiE9YmeEXz9h8TUVB.dsod6llrSS1IdSmljsc15NcnHgkX
CEgVdIxNYx+88b.HonjkjIkEc5tS8jXKBhaem6.mi93iNYzD40h7Qjul7KjS
N4iO5jSTMgMbR0ymLZdv0gIA4ptMJUrTN42GMV+pBw0EplSjAQSBRmV+h7ha
RDp2T2hrrHQTTbyBgd4Fo5N4WqdcZ473TnCpUgV03hfhvYwoS+sLQXgdXTWO
CtI7CeLg4ZaXNl3Xh+lwLLals3H0ZC6zujNZ0Jn2C5k.a7SO5Q3uF2QrGJmO
WjVbKv+8YAKlQjWQJSyCCRDQDXgVTVrahQWQK2wvwxzmZCnziivjZA3212zC
ZhY1BxSlFJSjY5wYZ3a56YZMV8IpuCE+jCmxc43m1Jkxxc6jJyCfTMWjmGLU
bKREyuGRH6P5fsGoCf5X63Qsb.pCkhDL68JcX4LXhGKxjERDMoAy0.c1G3tj
cIDYcF4YxxIIhvj3v2QJlIHoxBArmHvFEPHoPRxEEjKdwydQk.F1zkitJSNm
bQv0D5kiLHuYVbNYYbRBYhPMKp9Gmhc+JYF4FYYFLO+mRQZnHaLQXL0f7DXc
KjojWF+dgQ8VKINUDJKSU6O98VVl4Ya3Q8nJgYMugSYF1ftLJdZ4dXByzcvX
sNdBy6hk8ZTYugSkibi.xbYlfjIBxkoA.UkLuLOF5GICL2IFuUZK6nRas7UR
7TWtAGZxETE37iqgB9fQa6oRC+LxSmIk4BRTVY56TB3UrfZ5dvBXNCBmQBRi
VwmRhyKDojnXjFlbC1DxGmJREYAEfE72GjTJxMFH9E2zowNE+15BGJ+ZW5Br
g2vdXBvEFVa6NVFlUzLpkRFm6uWa6GQW+6B1RPRcPQsuUifRMnc2Gn49COnU
ZQCJpYfebuZiWZ8Cq85GmuiXWp0AmlEDEKzpuzsqXYhZR1b7G7STGOGl655T
UifUODlRED6MuQqjWoUt93tBbHqF6uUSWVsk1RmT+l1qc1FC9dsGWitbHS.3
qSKTvbws+s6.XSdgLqHVlpLDYv821rTVHay3fo5HJEq7XLrVr780V10Bvz8I
.y9SA3+T.teBvzGNSvVZeN9F16QB1b387X9fnu1EzRcOdncZ9xXXyb+wFeOX
yzS6EUenXsEocgsl36WDjAwgWHx9Mg5zLJg3iGWtLoHNOINRjUufgPT5PX6o
BqZsWKtOipzdc.UVSO0oRbMs87VW6cgH3cqo1aA55fV4V+T6AdaxcylnwFD0
xFLcfy.CFOioLg.wk4rQP2MizsdjdtdVbUP5LKLJ8wsls1i71r3wsYyMSrc8
DaiyqxVlGy0xVsDVa4b.a8HI4hBnUfYzxBMk09D3Z1x5m7vwD.y5qHcKDgsd
qcMmE0kptGKWFvPA6KLXBc818wcL4LeGaES2xjaqnelLepq6Nn77aa12hBqr
ZNfE2k4rA+eEY2byIyqYarhFaABeJgI6s3CocHoMVulEG9tTgVn2qCZVMKuS
8x6136DnALeESv0yiwsuEytkNIaEBaDx4Gfd5Nty2u.LpzCaVwnOvdaRVKsv
rc0Vl26Y.NhNf1AjiDIA2PLON2x8dfsGU46wWaldumxkcDOvGLCSVYKtK9gF
en2iOqkIAKa1ceSsLu96Th8GaZ.0i2jKCKVGtsZlyCDMX6R+pjaPLQOEPfDD
+iPzXN6QGfoE90Nm716sdvrFbU+BxjAO4VUp8Zicr8ZriwGdicpqTEY11GEy
776B3bskN28Cb1+SZui53nzu0fa+p4Tm+uyTmVYtan25ypQtpjt0wb2xuKHW
koq6v9E8HdC86.WyCdm.wFX1FhaqOltuJQFTfrd8G5uxsl2qu2ZpIeuDhcbm
8riXZ69puh7iAQAYXRezp.j3zUoJUQjTYqy3xTnuTHRelM46e9GH+7W9cXVj
tPh26C4YfnYXgLib5egyXT9YvnvocxMjkKWZfRuIIAWa.6C8L8jrnx3TInnX
3XvHmdQPH4Uul7ymMl7cxfrnulb4np9Pdap7xQ5g8bQZN4eGCfIadPJ4avLh
82tN2Blcizj+ppO+ixTArSwZBfZCCS03Sko4EAoE4pFBwm.jBNxBJi9w..km
SfyzY931uKQD8C.03bBkuV6.k8oX9u.h04n7i4luUQ6NGcWr1aJyeoTt3Yp3
lOGz7W6kWijS8x483pM8KRiKhCRHgxHAxg.mPDYZnPgg2KiivjfWt3zyHWl9
wKSIDjvlmGOMkLGFhJ6dKhSQLSH3+gGt.dwo0K1XxK9m+vaeyYOt8K0vdL4U
u8Mp2gCsZxecQPVArnY5c074kovgyTR.vRg4c2sYsdspWFSDSiSOslLCy1ko
eBmOE.Q5wZnagHaA.IfcdyJPl.8ZML9zLAxxBH4ygdRVFmFIWpDbimKHQkYf
RGYIbTyYjkBcA.nRXYkP4r3BMIAlpvJF46CfcKli5V8FUCBlq9n7J0nFSxg8
o.K8f3BRftK4HQwPSiPNY0TpnogMxIlOdCp3565Fx1UxrSwYIN5Z0nTe3aZI
y8XxW7EPamgcVQPveP8XQPUpZwc6bsdYNnuHyLp6V8ewEP+p+kZ.mShhmFWD
jfSRizgVrn83fk4Y.CYIlcX.+HM4aAozvLAZcQQMpP7sWxqNs0JdVcyMHf.v
pMkC+4SaY8e4e+Yj7Yxk4jvxrLbUA5eQYNB5VKvsV+J.9SYwEqDwaSC9Vxye
w2+bvn3Ke0OsUj+jJwM8AeemPr.TvP66vehit41qH1uKhCyj4BPOOJ+zVF.z
q.BvJghWklbSqRYoRGKF.kDjoqXmKCxgoEM0JhLpFKPXqnasEIPwLcIYHItj
I0R706tvYfdP0pcNHbsndNFCQUzRXq9Qzh1YURv5sa0NEK3iF+FpEpwewpUq
xTvBPur3T8p1fe3easvBbcu2UVfqqtLwr0AZo74555b+qmfqjfij3On1UzU4
Dosu6lfJv91T.G.UMKdUXlCW43TwdTkCUsazewjXXfNk906ew3wL8ZJxlphK
qcQ1bjqFOu+nTiMryHuoLCcBq7CqD+yhmNS4SDyAFYFngNQHRAMLPsOcnJZl
VkBgCyvw2AucWps0PU1L1CuHK8LH.oIXbKyu55qutot8ZEEnADmIvphxQFf1
+9ae82QTDdIDzWY9vUlRLWpgGV+orZKJLt+prBdbI27g+LP4hDBs+We63U+s
+m9ocA7XVYa16VGAZMqqrsYcky2p00mjFgd7tPlJ2N46Ptv+B4TL82GiK8g1
ojBATDpVelw12wCcLeXxL4tNCsnHSRnC90+2hxTIyTckfa5P9pfv0P9ZhQzs
IF4POLwH5wTKTElWf5vm8THa2pfcywA90GPcKDVaUEbuzyspV5bfpkGxEZDT
TjUFePW5NNzZhO55XzgqqV4HXK0i2gQA412eIR0VP48aiuLKJnfsuNYMGhIM
rlJUyFIqPRjHuHNMnt7d9kUeYA.+G0cZVbTjHsMXmGGsPBho400bwpJVkQ04
wvRK3s9S5vzod9q5tY6jwGEmi13h1s6viJNwDo1pS8CmVZebffgc0SetfAie
uggNAreVQAVLND18iY3X2.ilm35ajlZoJyI0SCADoc.hN8jQwbZhAkpynPaP
qZZHfhYWfB8fghmVVa8F9bgC9gyRzIrcK+1YSNkuyf.PqgPlCOoeSPDZMn0D
5vlF.rfky+wGKatwefvhaWLZ2SeOL3nCq9ZN4nKVnMZZHvh8vZWS+Magu5K4
h1z8Cm0NkA.5cEPD8dnDwbpuAs0ZZnvxcZwy+dnDwtkssACKcw5MVSX8JP0p
n0zYpkpKEI0SC.BXcwjFVkG8ga3W8cnydUTapGFh8uWW1+VPmr5gpeKceK2p
ZEv1vu5og.FcwZL0smVvL8TQSVYHt0SCABb5Jif2CUAelgWcM4oOdF1T8SCA
Lr5Bif1a8AarL+qOES8CCw9m2UKR8Vetxfj+vZOh00SgQ6s8npyXw4C4YrXl
cE.GZbUUvf5Njvf5NDvnxDzCCB5hAIrTu5kuYWak1quFAsdZHPfUWQP+sEoA
PqGFh8emhzqmA5oEZp8JqKI+1O3p+pU0xCtpkOWvaC+I8DeZ9yPEzgxM1ccp
hMTi5rFhCssFhCc3PvcpgXcPZHZ.z5ggX+O.Q8gE2ZcLSbKV6P+r5hOa8s2G
rXw6EY4UaEE.FMO3204TVUXLv5lpeTsQFkIdebc+UYfcTPV3rXrTgJyzYQ3Z
Gc0DOBywdVZYbUlCfU9SO5+R5rb5r
-----------end_max5_patcher-----------

Step 8: Turning Random Notes Into a Scale in Ableton Live

The note output from Max is still quite random, not very musically pleasing. This is where Ableton Live steps in!

Start Ableton Live and create a MIDI track with an instrument of your choice. Bells and plucked sounds work very well. You can add some reverb to the output of the instrument as well.

Now before the MIDI instrument you will place a MIDI effect that will force all incoming notes into a scale of your choice. You find this object under MIDI Effects and it is called "Scale". You can try out different scales and hot swap them to find the one that suits your mood. The "Phrygian Mode" is one of my favourites.

If no sound comes from Ableton Live, be sure you have record enabled your MIDI instrument (the red rectangular button should light up for that channel). Also make sure "from Max 1" is visible in your Ableton Live preferences and has Track and Remote enabled.

Now have fun performing musical moves in front of your Arduino!

<p>Hi, thanks for sharing! Would it be possible to translate this to a PIR sensor, if the output from Ableton were to be loops and not notes? </p>
Hi Lilia,<br><br>Sure thing. Reading a PIR sensor is very similar. See for instance this article:<br><br>http://playground.arduino.cc/Code/PIRsense<br><br>You're basically doing the same; a digitalRead from a pin and then sending something down the serial line to Max. To start clips, you're gonna wanna use the Ableton Live Object Model from Max:<br><br>https://docs.cycling74.com/max7/vignettes/live_object_model<br><br>If you can't make it work, there's a whole community of Max enthusiasts who are very helpful in the forums:<br><br>https://cycling74.com/forums/<br><br>Alternatively, you can still fire MIDI events from Max to Live (and use Max as a MIDI input in Live) and use notes or cc's as midi learn events in Live. Have fun!<br><br>Hens Zimmerman
<p>This is very interesting.Thanks for letting us know such a wonderful thing.</p>

About This Instructable

5,191views

54favorites

License:

Bio: Too much television as a kid.
More by hzimmerman:Computing complex circuits with a TI calculator How to make your own delicious and healthy bread Controlling a relay board with an Arduino Uno 
Add instructable to: