//Tremolo(panner) effect has its parameters precalculated here in software.
//The user only takes care of choosing the depth and rate of the trembling,
//whereas the hardware receives calculated slope parameters.
static void tremoloSendParams() {
float slope, diff, best_diff;
float actualRate;
unsigned int a, b, j, k, depth;
if (_tremoloDepth < 0 || _tremoloRate < 0) return;
//The actual, ideal slope
slope = 2 * _tremoloDepth*((1<<16)-1)*_tremoloRate / 48000;
best_diff = infinityf();
//The hardware receives the slope of the trembling in the form of a
//rational number a/b.
//We find the closest approximation of the actual slope.
for (k = 1; k<16; k++) {
j = (int)roundf(slope*k);
if (j < 1) j = 1;
if (j > 15) j = 15;
diff = fabsf( ((float)a/b) - slope);
if (diff < best_diff) {
a = j;
b = k;
best_diff = diff;
}
}
depth = (int)floorf(_tremoloDepth * ((1<<16)-1));
IOWR_16DIRECT(PIO_TREMOLO_STEREO_DEPTH_BASE, 0, depth);
IOWR_16DIRECT(PIO_TREMOLO_STEREO_SWEEP_A_BASE, 0, a);
IOWR_16DIRECT(PIO_TREMOLO_STEREO_SWEEP_B_BASE, 0, b);
}
float Thermistor::adc_value_to_temperature(int adc_value)
{
if ((adc_value == 4095) || (adc_value == 0))
return infinityf();
float r = r2 / ((4095.0 / adc_value) - 1.0);
if (r1 > 0)
r = (r1 * r) / (r1 - r);
return (1.0 / (k + (j * log(r / r0)))) - 273.15;
}
float Thermistor::adc_value_to_temperature(int adc_value)
{
if ((adc_value == 4095) || (adc_value == 0))
return infinityf();
// resistance of the thermistor in ohms
float r = r2 / ((4095.0F / adc_value) - 1.0F);
if (r1 > 0.0F) r = (r1 * r) / (r1 - r);
float t;
if(this->use_steinhart_hart) {
float l = logf(r);
t= (1.0F / (this->c1 + this->c2 * l + this->c3 * powf(l,3))) - 273.15F;
}else{
// use Beta value
t= (1.0F / (k + (j * logf(r / r0)))) - 273.15F;
}
return t;
}
float Thermistor::get_temperature()
{
if(bad_config) return infinityf();
return adc_value_to_temperature(new_thermistor_reading());
}
