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AP_Airspeed: use new voltage_average() API in Airspeed driver

This commit is contained in:
Andrew Tridgell 2013-03-08 10:01:15 +11:00
parent bf1944a36d
commit 00e905b025
2 changed files with 15 additions and 9 deletions
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23
libraries/AP_Airspeed/AP_Airspeed.cpp
View File

@ -45,6 +45,13 @@ const AP_Param::GroupInfo AP_Airspeed::var_info[] PROGMEM = {
AP_GROUPEND
};
/*
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
voltage in volts directly from the ADC driver
*/
#define SCALING_OLD_CALIBRATION 204.8f // 1024/5
// calibrate the airspeed. This must be called at least once before
// the get_airspeed() interface can be used
void AP_Airspeed::calibrate()
@ -54,13 +61,13 @@ void AP_Airspeed::calibrate()
if (!_enable) {
return;
}
_source->read_average();
_source->voltage_average();
for (c = 0; c < 10; c++) {
hal.scheduler->delay(100);
sum += _source->read_average();
sum += _source->voltage_average() * SCALING_OLD_CALIBRATION;
}
_airspeed_raw = sum/c;
_offset.set_and_save(_airspeed_raw);
float raw = sum/c;
_offset.set_and_save(raw);
_airspeed = 0;
}
@ -71,8 +78,8 @@ void AP_Airspeed::read(void)
if (!_enable) {
return;
}
_airspeed_raw = _source->read_average();
airspeed_pressure = max(_airspeed_raw - _offset, 0);
_airspeed = 0.7f * _airspeed +
0.3f * sqrtf(airspeed_pressure * _ratio);
float raw = _source->voltage_average() * SCALING_OLD_CALIBRATION;
airspeed_pressure = max(raw - _offset, 0);
float new_airspeed = sqrtf(airspeed_pressure * _ratio);
_airspeed = 0.7f * _airspeed + 0.3f * new_airspeed;
}

1
libraries/AP_Airspeed/AP_Airspeed.h
View File

@ -59,7 +59,6 @@ private:
AP_Int8 _use;
AP_Int8 _enable;
float _airspeed;
float _airspeed_raw;
};