/* digOscOP1.c	XH@26Jan'21
 * Berechnung des Digitaloszillator-Arbeitspunktes
 *   mittels FE-numerischer Integration
 * compile:  'gcc digOscOP1.c -o digOsc.exe'
 * run:      './digOsc.exe'
 * stop:     Strg+C
 * OS:       Linux (Knoppix v8.6)
 */

#include <stdio.h>
#include <time.h>

struct timespec t={0L, 300000000L};

#define Vcc	5.0
double	Uc  = 0.0;
double  Uin;
double  R1  = 1000.;
double  C   = 1E-7;
double	dt  = 1E-5;
double  Ir,dUc,Uin;
int	inv1=0;
int	inv2=1;

int main(int argc, char *argv[]){

  for(;;){
    Uin = (inv2*Vcc) + Uc;
    if( Uin > Vcc/2 ){	inv1 = 0;
    }else{		inv1 = 1;
    }
    inv2 = inv1 ? 0 : 1;

    Ir   = (inv1*Vcc-Uin)/R1;
    dUc  = dt*Ir/C;
    Uc   += dUc;

    printf("Ir=%9g, dUc=%9g, Uc=%9g, Uin=%9g\n", Ir,dUc,Uc,Uin);
    nanosleep( &t, NULL );
  }
}