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Introduce analog scaling parameter for analog airspeed sensor

This commit is contained in:
Lorenz Meier 2014-07-11 09:10:35 +02:00
parent 56e1fe382b
commit 3461d3d215
2 changed files with 17 additions and 11 deletions
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10
src/modules/sensors/sensor_params.c
View File

@ -194,16 +194,22 @@ PARAM_DEFINE_FLOAT(SENS_ACC_ZSCALE, 1.0f);
/**
* Differential pressure sensor offset
*
* The offset (zero-reading) in Pascal
*
* @group Sensor Calibration
*/
PARAM_DEFINE_FLOAT(SENS_DPRES_OFF, 0.0f);
/**
* Differential pressure sensor analog enabled
* Differential pressure sensor analog scaling
*
* Pick the appropriate scaling from the datasheet.
* this number defines the (linear) conversion from voltage
* to Pascal (pa).
*
* @group Sensor Calibration
*/
PARAM_DEFINE_INT32(SENS_DPRES_ANA, 0);
PARAM_DEFINE_FLOAT(SENS_DPRES_ANSC, 0);
/**

18
src/modules/sensors/sensors.cpp
View File

@ -248,7 +248,7 @@ private:
float accel_offset[3];
float accel_scale[3];
float diff_pres_offset_pa;
float diff_pres_analog_enabled;
float diff_pres_analog_scale;
int board_rotation;
int external_mag_rotation;
@ -311,7 +311,7 @@ private:
param_t mag_offset[3];
param_t mag_scale[3];
param_t diff_pres_offset_pa;
param_t diff_pres_analog_enabled;
param_t diff_pres_analog_scale;
param_t rc_map_roll;
param_t rc_map_pitch;
@ -590,7 +590,7 @@ Sensors::Sensors() :
/* Differential pressure offset */
_parameter_handles.diff_pres_offset_pa = param_find("SENS_DPRES_OFF");
_parameter_handles.diff_pres_analog_enabled = param_find("SENS_DPRES_ANA");
_parameter_handles.diff_pres_analog_scale = param_find("SENS_DPRES_ANSC");
_parameter_handles.battery_voltage_scaling = param_find("BAT_V_SCALING");
_parameter_handles.battery_current_scaling = param_find("BAT_C_SCALING");
@ -798,7 +798,7 @@ Sensors::parameters_update()
/* Airspeed offset */
param_get(_parameter_handles.diff_pres_offset_pa, &(_parameters.diff_pres_offset_pa));
param_get(_parameter_handles.diff_pres_analog_enabled, &(_parameters.diff_pres_analog_enabled));
param_get(_parameter_handles.diff_pres_analog_scale, &(_parameters.diff_pres_analog_scale));
/* scaling of ADC ticks to battery voltage */
if (param_get(_parameter_handles.battery_voltage_scaling, &(_parameters.battery_voltage_scaling)) != OK) {
@ -1323,22 +1323,22 @@ Sensors::adc_poll(struct sensor_combined_s &raw)
} else if (ADC_AIRSPEED_VOLTAGE_CHANNEL == buf_adc[i].am_channel) {
/* calculate airspeed, raw is the difference from */
float voltage = (float)(buf_adc[i].am_data) * 3.3f / 4096.0f * 2.0f; //V_ref/4096 * (voltage divider factor)
float voltage = (float)(buf_adc[i].am_data) * 3.3f / 4096.0f * 2.0f; // V_ref/4096 * (voltage divider factor)
/**
* The voltage divider pulls the signal down, only act on
* a valid voltage from a connected sensor. Also assume a non-
* zero offset from the sensor if its connected.
*/
if (voltage > 0.4f && (_parameters.diff_pres_analog_enabled > 0)) {
if (voltage > 0.4f && (_parameters.diff_pres_analog_scale > 0)) {
float diff_pres_pa = voltage * 1000.0f - _parameters.diff_pres_offset_pa; //for MPXV7002DP sensor
float diff_pres_pa = voltage * _parameters.diff_pres_analog_scale;
_diff_pres.timestamp = t;
_diff_pres.differential_pressure_pa = diff_pres_pa;
_diff_pres.differential_pressure_pa = diff_pres_pa - _parameters.diff_pres_offset_pa;
_diff_pres.differential_pressure_raw_pa = diff_pres_pa;
_diff_pres.differential_pressure_filtered_pa = diff_pres_pa;
_diff_pres.temperature = -1000.0f;
_diff_pres.voltage = voltage;
/* announce the airspeed if needed, just publish else */
if (_diff_pres_pub > 0) {