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tweaks to cal_binary() so that it gets the last, least significant

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bit correct.
This commit is contained in:
Frank Mori Hess 2003-04-27 00:03:27 +00:00
parent 46e32500de
commit a372e7340d
2 changed files with 24 additions and 23 deletions
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1
comedi_calibrate/calib.h
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@ -195,7 +195,6 @@ typedef struct{
comedi_range *rng;
int n;
double average;
double stddev;
double error;

46
comedi_calibrate/comedi_calibrate.c
View file

@ -463,52 +463,54 @@ void cal1_fine( calibration_setup_t *setup, int obs, int dac )
void cal_binary( calibration_setup_t *setup, int obs, int dac)
{
int x1, x2, x;
double y1, y2, y;
int x0, x;
unsigned int bit;
double y0, y;
new_sv_t sv;
double target = setup->observables[obs].target;
unsigned int chanspec = setup->observables[obs].observe_insn.chanspec;
int polarity;
DPRINT(0,"binary: %s\n", setup->observables[obs].name);
preobserve( setup, obs);
x1 = 0;
x2 = setup->caldacs[dac].maxdata;
bit = 1;
while( ( bit << 1 ) < setup->caldacs[dac].maxdata )
bit <<= 1;
new_sv_init(&sv, setup->dev,0,chanspec);
sv.settling_time_ns = setup->settling_time_ns;
update_caldac( setup, dac, x1 );
x0 = 0;
update_caldac( setup, dac, x0 );
usleep(100000);
new_sv_measure( setup->dev, &sv);
y1 = sv.average;
y0 = sv.average;
new_sv_init(&sv, setup->dev,0,chanspec);
sv.settling_time_ns = setup->settling_time_ns;
update_caldac( setup, dac, x2 );
x = bit;
update_caldac( setup, dac, x );
usleep(100000);
new_sv_measure( setup->dev, &sv);
y2 = sv.average;
y = sv.average;
x = 0;
while(x2-x1 > 1){
x = (x1 + x2 + 1)/2;
if( y > y0 ) polarity = 1;
else polarity = -1;
if( (y - target) * polarity > 0.0 )
x &= ~bit;
for( bit = bit >> 1; bit; bit >>= 1 ){
x |= bit;
DPRINT(3,"trying %d\n",x);
new_sv_init(&sv, setup->dev,0,chanspec);
sv.settling_time_ns = setup->settling_time_ns;
update_caldac( setup, dac, x );
usleep(100000);
new_sv_measure( setup->dev, &sv);
y = sv.average;
if(fabs(y2 - target) > fabs(y1 - target)){
x2 = x;
y2 = y;
}else{
x1 = x;
y1 = y;
}
if( (y - target) * polarity > 0.0 )
x &= ~bit;
if(verbose>=3){
measure_observable( setup, obs);