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AP_Airspeed: use rationmetric analog input for airspeed sensor

This commit is contained in:
Andrew Tridgell 2013-05-13 15:13:19 +10:00
parent 589b8cdb58
commit dfb98490f4
1 changed files with 5 additions and 5 deletions
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10
libraries/AP_Airspeed/AP_Airspeed.cpp
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@ -47,10 +47,10 @@ const AP_Param::GroupInfo AP_Airspeed::var_info[] PROGMEM = {
/*
this scaling factor converts from the old system where we used a
0 to 1023 raw ADC value for 0-5V to the new system which gets the
0 to 4095 raw ADC value for 0-5V to the new system which gets the
voltage in volts directly from the ADC driver
*/
#define SCALING_OLD_CALIBRATION 204.8f // 1024/5
#define SCALING_OLD_CALIBRATION 819 // 4095/5
// calibrate the airspeed. This must be called at least once before
// the get_airspeed() interface can be used
@ -61,10 +61,10 @@ void AP_Airspeed::calibrate()
if (!_enable) {
return;
}
_source->voltage_average();
_source->voltage_average_ratiometric();
for (c = 0; c < 10; c++) {
hal.scheduler->delay(100);
sum += _source->voltage_average() * SCALING_OLD_CALIBRATION;
sum += _source->voltage_average_ratiometric() * SCALING_OLD_CALIBRATION;
}
float raw = sum/c;
_offset.set_and_save(raw);
@ -78,7 +78,7 @@ void AP_Airspeed::read(void)
if (!_enable) {
return;
}
float raw = _source->voltage_average() * SCALING_OLD_CALIBRATION;
float raw = _source->voltage_average_ratiometric() * SCALING_OLD_CALIBRATION;
airspeed_pressure = max(raw - _offset, 0);
float new_airspeed = sqrtf(airspeed_pressure * _ratio);
_airspeed = 0.7f * _airspeed + 0.3f * new_airspeed;