MEMS cvičenie 2

• Návod na cvičenia:

• Príklad na pripojenie analógového senzora: http://ap.urpi.fei.stuba.sk/sensorwiki/index.php/Acrob007
• Riadiaca doska Acrob http://ap.urpi.fei.stuba.sk/sensorwiki/index.php/Acrob
• Arduino homepage https://www.arduino.cc/

#define SerialSpeed 9600   //typical values are 9600 or 115200
#define SampFrequency 10   //sampling frequency in Hz (cycles per second)
#define positionSensor 5        //define your pin here
 
int mDelay;
int adcValue;
float outputValue;

void setup()
{
 Serial.begin(SerialSpeed);
 mDelay = 1000/SampFrequency; //calculate delay for proper sampling rate
}
 
void loop()
{
 adcValue = analogRead(positionSensor);
 /*  =============================================== */
 outputValue = adcValue;   // replace this line with your code 
 /*  =============================================== */
 Serial.print( outputValue ); //reads the analog port and prints value over serial
 Serial.print('\n');
 delay(mDelay); //delay in milliseconds

}

1. Look-up table

<source lang="cpp">

#include <avr/pgmspace.h>

const PROGMEM int table[] = {11,12,15,...};

<source lang="cpp">

Viac info tu: https://www.arduino.cc/en/Reference/PROGMEM

2. Po častiach lineárna náhrada

<source lang="cpp">

if (adcValue > x1) && (adcValue <= x2)
  y = k2 & adcValue + q2;

return(y)

<source lang="cpp">

3. Aproximácia funkcie

• http://terpconnect.umd.edu/~toh/spectrum/CurveFitting.html

• https://www.gnu.org/software/octave/doc/interpreter/Polynomial-Interpolation.html
• http://octave.sourceforge.net/optim/function/leasqr.html
• http://octave.sourceforge.net/optim/function/expfit.html
• https://www.gnu.org/software/gsl/manual/html_node/Example-programs-for-Nonlinear-Least_002dSquares-Fitting.html
• https://www.gnu.org/software/octave/doc/interpreter/One_002ddimensional-Interpolation.html#One_002ddimensional-Interpolation

Odovzdať:

• Chyby podľa EN 60 770
  • Nepresnosť
  • Meraná chyba
  • Nelinearita
  • Hysteréza
  • Neopakovateľnosť
• Graf 1: prevodová charakteristika
• Graf 2: chybové krivky (viď obr.)
• Program pre mikroprocesor

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