dimanche 25 septembre 2011

Some Vids and Pics







video



video


Electronics

Here are the electronics components we used:


.1 transistor 2N2222
.1 resistor 1ko
.2 resistor 100ko
.1 diode 1N4004
.1 static relay Sharp S216S02
.1 74HC00N
.1 capacitor 100n
.2 capacitor 10p
.1 capacitor 150p (NP0 type)
.1 self radial 10uH

The 1T relay you see in the center of the picture was then replaced by a static one




























Here is the website for the Printed Circuit (Bordeaux - France):
As cheap as fast.


Send us a mail if you need the Phototool





Here it goes, ready to be plugged directly on the Arduino.

Code

We only add a threshold to digital write a pin.
If the circuit receives a sufficient amount of frequency, it commands a passive relay to switch on a bulb light.

Here is the code we used:

/*From Off to On
 *by Romée de la Bigne
 * for Hold Up
 
 *based on
 * Theremin Test
 * http://interface.khm.de/index.php/lab/experiments/theremin-as-a-capacitive-sensing-device/
 * Therremin with TTL Oscillator 4MHz
 * Timer1 for freauency measurement
 * Timer2 for gate time
 * connect Oscillator on digital pin 5
 * connect Speaker with 1K Resistor in series on pin 8

 * KHM 2008 /  Martin Nawrath
 * Kunsthochschule fuer Medien Koeln
 * Academy of Media Arts Cologne

 */
#include <Stdio.h>
#define cbi(sfr, bit) (_SFR_BYTE(sfr) &= ~_BV(bit))
#define sbi(sfr, bit) (_SFR_BYTE(sfr) |= _BV(bit))

//! Macro that clears all Timer/Counter1 interrupt flags.
#define CLEAR_ALL_TIMER1_INT_FLAGS    (TIFR1 = TIFR1)

int pinFreq = 5;

void setup()
{
  pinMode(pinFreq, INPUT);
  pinMode(4, OUTPUT);

  Serial.begin(57600);        // connect to the serial port

  // hardware counter setup ( refer atmega168.pdf chapter 16-bit counter1)
  TCCR1A=0;                   // reset timer/counter1 control register A
  TCCR1B=0;                   // reset timer/counter1 control register A
  TCNT1=0;                    // counter value = 0
  // set timer/counter1 hardware as counter , counts events on pin T1 ( arduino pin 5)
  // normal mode, wgm10 .. wgm13 = 0
  sbi (TCCR1B ,CS10);         // External clock source on T1 pin. Clock on rising edge.
  sbi (TCCR1B ,CS11);
  sbi (TCCR1B ,CS12);

  // timer2 setup / is used for frequency measurement gatetime generation
  // timer 2 presaler set to 256 / timer 2 clock = 16Mhz / 256 = 62500 Hz
  cbi (TCCR2B ,CS20);
  sbi (TCCR2B ,CS21);
  sbi (TCCR2B ,CS22);

  //set timer2 to CTC Mode
  cbi (TCCR2A ,WGM20);
  sbi (TCCR2A ,WGM21);
  cbi (TCCR2B ,WGM22);
  OCR2A = 124;                  // CTC at top of OCR2A / timer2 interrupt when coun value reaches OCR2A value

  // interrupt control

  sbi (TIMSK2,OCIE2A);          // enable Timer2 Interrupt

}

volatile byte i_tics;
volatile byte f_ready ;
volatile byte mlt ;
unsigned int ww;

int cal;
int cal_max;

char st1[32];
long freq_in;
long freq_zero;
long freq_cal;

unsigned int dds;
int tune;

int cnt=0;

void loop()
{
  cnt++;
  // add=analogRead(0);

  f_meter_start();

  tune=tune+1;
  while (f_ready==0) {            // wait for period length end (100ms) by interrupt
    PORTB=((dds+=tune) >> 15);    // kind of DDS tonegenerator / connect speaker to portb.0 = arduino pin8
  }
 tune = freq_in-freq_zero;
 // use the tune value here for your own purposes like control of servos, midi etc.

  // startup
  if (cnt==10) {
    freq_zero=freq_in;
    freq_cal=freq_in;
    cal_max=0;
    Serial.print("** START **");
  }

  // autocalibration
  
  if (cnt % 20 == 0) {   // try autocalibrate after n cycles
    Serial.print("*");
    if (cal_max <= 2) {
      freq_zero=freq_in;
      Serial.print(" calibration");
    }
    freq_cal=freq_in;
    cal_max=0;
    Serial.println("");
    
  }
  
  cal = freq_in-freq_cal;
  if ( cal < 0) cal*=-1;  // absolute value
  if (cal > cal_max) cal_max=cal;


  if ( tune < 0) tune*=-1;  // absolute value
   sprintf(st1, " %04d",tune);
  Serial.print(st1);
  Serial.print("  "); 

  Serial.print(freq_in);
  Serial.print("  ");
/*
  Serial.print(freq_zero);
  Serial.print("  ");
  Serial.print(cal_max);
*/
  Serial.print("  ");
  Serial.print(tune);
  Serial.println("  ");
 
/*
  Set Up a threshold for detection
  And command the relay

*/
  if (cnt % 2 == 0) {
  if (tune>200)
  digitalWrite(4, HIGH);
  else 
  digitalWrite(4, LOW);
  }
 }

//******************************************************************
void f_meter_start() {
  f_ready=0;                      // reset period measure flag
  i_tics=0;                        // reset interrupt counter
  sbi (GTCCR,PSRASY);              // reset presacler counting
  TCNT2=0;                         // timer2=0
  TCNT1=0;                         // Counter1 = 0
  cbi (TIMSK0,TOIE0);              // dissable Timer0 again // millis and delay
  sbi (TIMSK2,OCIE2A);             // enable Timer2 Interrupt
  TCCR1B = TCCR1B | 7;             //  Counter Clock source = pin T1 , start counting now
}

//******************************************************************
// Timer2 Interrupt Service is invoked by hardware Timer2 every 2ms = 500 Hz
//  16Mhz / 256 / 125 / 500 Hz
// here the gatetime generation for freq. measurement takes place: 

ISR(TIMER2_COMPA_vect) {

  if (i_tics==50) {         // multiple 2ms = gate time = 100 ms
                            // end of gate time, measurement ready
    TCCR1B = TCCR1B & ~7;   // Gate Off  / Counter T1 stopped
    cbi (TIMSK2,OCIE2A);    // disable Timer2 Interrupt
    sbi (TIMSK0,TOIE0);     // ensable Timer0 again // millis and delay
    f_ready=1;              // set global flag for end count period

                            // calculate now frequeny value
    freq_in=0x10000 * mlt;  // mukt #ovverflows by 65636
    freq_in += TCNT1;       // add counter1 value
    mlt=0;

  }
  i_tics++;                 // count number of interrupt events
  if (TIFR1 & 1) {          // if Timer/Counter 1 overflow flag
    mlt++;                  // count number of Counter1 overflows
    sbi(TIFR1,TOV1);        // clear Timer/Counter 1 overflow flag
  }

}

//******************************************************************
 

Thank's, source and credits

Here is a vey useful experiment from Martin Nawrath / KHM :
http://interface.khm.de/index.php/lab/experiments/theremin-as-a-capacitive-sensing-device/

We would like to make a BIG thank's to Martin Nawrath for sharing his useful experience and to Lionel from Snootlab for his great help.