drivers: auav, read sensor eeprom to get cal range (#26294)

* drivers: auav, read sensor eeprom to get cal range

* added review feedback

src/drivers/differential_pressure/auav/AUAV.cpp

@@ -77,6 +77,10 @@ AUAV::~AUAV()
 void AUAV::RunImpl()
 {
 	switch (_state) {
+	case STATE::READ_FACTORY_DATA:
+		handle_state_read_factory_data();
+		break;
+
 	case STATE::READ_CALIBDATA:
 		handle_state_read_calibdata();
 		break;
@@ -107,23 +111,6 @@ int AUAV::init()
 		return ret;
 	}
 
-	int32_t hw_model = 0;
-	param_get(param_find("SENS_EN_AUAVX"), &hw_model);
-
-	switch (hw_model) {
-	case 1: /* AUAV L05D (+- 5 inH20) */
-		_cal_range = 10.0f;
-		break;
-
-	case 2: /* AUAV L10D (+- 10 inH20) */
-		_cal_range = 20.0f;
-		break;
-
-	case 3: /* AUAV L30D (+- 30 inH20) */
-		_cal_range = 60.0f;
-		break;
-	}
-
 	ScheduleClear();
 	ScheduleNow();
 	return PX4_OK;
@@ -148,6 +135,20 @@ int AUAV::probe()
 	return PX4_ERROR;
 }
 
+void AUAV::handle_state_read_factory_data()
+{
+	int status = read_factory_data();
+
+	if (status == PX4_OK) {
+		/* Factory data read or sensor does not have any, move to next state */
+		_state = STATE::READ_CALIBDATA;
+		ScheduleNow();
+
+	} else {
+		ScheduleDelayed(100_ms);
+	}
+}
+
 void AUAV::handle_state_read_calibdata()
 {
 	int status = PX4_OK;

src/drivers/differential_pressure/auav/AUAV.hpp

@@ -61,6 +61,7 @@ public:
 
 protected:
 	enum class STATE : uint8_t {
+		READ_FACTORY_DATA,
 		READ_CALIBDATA,
 		REQUEST_MEASUREMENT,
 		GATHER_MEASUREMENT
@@ -107,7 +108,9 @@ protected:
 	virtual int64_t get_conversion_interval() const = 0;
 	virtual calib_eeprom_addr_t get_calib_eeprom_addr() const = 0;
 	virtual float process_pressure_dig(const float pressure_dig) const = 0;
+	virtual int read_factory_data() = 0;
 
+	void handle_state_read_factory_data();
 	void handle_state_read_calibdata();
 	void handle_state_request_measurement();
 	void handle_state_gather_measurement();
@@ -117,8 +120,7 @@ protected:
 	float correct_pressure(const uint32_t pressure_raw, const uint32_t temperature_raw) const;
 	float process_temperature_raw(const float temperature_raw) const;
 
-	float _cal_range{10.0f};
-	STATE _state{STATE::READ_CALIBDATA};
+	STATE _state{STATE::READ_FACTORY_DATA};
 	calib_data_t _calib_data {};
 
 	perf_counter_t _sample_perf;

src/drivers/differential_pressure/auav/AUAV_Absolute.cpp

@@ -77,3 +77,9 @@ float AUAV_Absolute::process_pressure_dig(const float pressure_dig) const
 	const float pressure_mbar = 250.f + 1.25f * ((pressure_dig - (0.1f * (1 << 24))) / (1 << 24)) * 1000.f;
 	return pressure_mbar * MBAR_TO_PA;
 }
+
+int AUAV_Absolute::read_factory_data()
+{
+	/* Absolute sensor doesn't need to read factory data */
+	return PX4_OK;
+}

src/drivers/differential_pressure/auav/AUAV_Absolute.hpp

@@ -68,6 +68,7 @@ private:
 	int64_t get_conversion_interval() const override;
 	calib_eeprom_addr_t get_calib_eeprom_addr() const override;
 	float process_pressure_dig(const float pressure_dig) const override;
+	int read_factory_data() override;
 
 	uORB::PublicationMulti<sensor_baro_s> _sensor_baro_pub{ORB_ID(sensor_baro)};
 };

src/drivers/differential_pressure/auav/AUAV_Differential.cpp

@@ -33,10 +33,38 @@
 
 #include "AUAV_Differential.hpp"
 #include <parameters/param.h>
+#include <cctype>
 
 AUAV_Differential::AUAV_Differential(const I2CSPIDriverConfig &config) :
 	AUAV(config)
 {
+	/* Initialize cal_range from parameter as fallback value */
+	int32_t hw_model = 0;
+	param_get(param_find("SENS_EN_AUAVX"), &hw_model);
+
+	switch (hw_model) {
+	case 1: /* AUAV L05D (+- 5 inH20) */
+		_cal_range = 10;
+		break;
+
+	case 2: /* AUAV L10D (+- 10 inH20) */
+		_cal_range = 20;
+		break;
+
+	case 3: /* AUAV L30D (+- 30 inH20) */
+		_cal_range = 60;
+		break;
+
+	default:
+		_cal_range = 10; /* Default fallback */
+		break;
+	}
+}
+
+void AUAV_Differential::print_status()
+{
+	AUAV::print_status();
+	PX4_INFO("cal range: %" PRId32, _cal_range);
 }
 
 void AUAV_Differential::publish_pressure(const float pressure_p, const float temperature_c,
@@ -83,6 +111,52 @@ AUAV::calib_eeprom_addr_t AUAV_Differential::get_calib_eeprom_addr() const
 
 float AUAV_Differential::process_pressure_dig(const float pressure_dig) const
 {
-	const float pressure_in_h = 1.25f * ((pressure_dig - (1 << 23)) / (1 << 24)) * _cal_range;
+	const float pressure_in_h = 1.25f * ((pressure_dig - (1 << 23)) / (1 << 24)) * static_cast<float>(_cal_range);
 	return pressure_in_h * INH_TO_PA;
 }
+
+int AUAV_Differential::read_factory_data()
+{
+	/* The differential sensor needs the cal_range from the absolute sensor's EEPROM.
+	 * Temporarily switch to the absolute sensor's I2C address to read it, then switch back. */
+
+	uint8_t original_address = get_device_address();
+	set_device_address(I2C_ADDRESS_ABSOLUTE);
+
+	/* Read the calibration range from the absolute sensor's EEPROM */
+	uint16_t factory_data = 0;
+	int status = read_calibration_eeprom(EEPROM_ABS_CAL_RNG, factory_data);
+
+	set_device_address(original_address);
+
+	if (status != PX4_OK) {
+		return status;
+	}
+
+	/* If EEPROM data is 0, stop trying (sensor does not have factory data) */
+	if (factory_data == 0) {
+		PX4_INFO("Differential: cal range data is 0, using fallback value");
+		return PX4_OK;
+	}
+
+	/* Decode the two bytes as ASCII characters */
+	uint8_t char_high = (factory_data >> 8) & 0xFF;
+	uint8_t char_low = factory_data & 0xFF;
+
+	/* Validate that both characters are ASCII digits (0-9) */
+	if (!isdigit(char_high) || !isdigit(char_low)) {
+		return PX4_ERROR;
+	}
+
+	int32_t sensor_type = ((char_high - '0') * 10) + (char_low - '0');
+
+	/* Check if the detected sensor type is valid */
+	if (sensor_type != AUAV_LD_05 && sensor_type != AUAV_LD_10 && sensor_type != AUAV_LD_30) {
+		return PX4_ERROR;
+	}
+
+	_cal_range = sensor_type * 2;
+	PX4_INFO("Differential: read cal range %" PRId32 " from absolute sensor EEPROM", _cal_range);
+
+	return PX4_OK;
+}

src/drivers/differential_pressure/auav/AUAV_Differential.hpp

@@ -37,6 +37,7 @@
 #include <uORB/topics/differential_pressure.h>
 
 /* AUAV EEPROM addresses for differential channel */
+static constexpr uint8_t EEPROM_ABS_CAL_RNG	= 0x25;
 static constexpr uint8_t EEPROM_DIFF_AHW 	= 0x2B;
 static constexpr uint8_t EEPROM_DIFF_ALW 	= 0x2C;
 static constexpr uint8_t EEPROM_DIFF_BHW 	= 0x2D;
@@ -57,17 +58,26 @@ static_assert(DIFF_CONVERSION_INTERVAL >= 7000, "Conversion interval is too fast
 /* Conversions */
 static constexpr float INH_TO_PA = 249.08f;
 
+/* Valid AUAV types */
+static constexpr int32_t AUAV_LD_05 = 5;
+static constexpr int32_t AUAV_LD_10 = 10;
+static constexpr int32_t AUAV_LD_30 = 30;
+
 class AUAV_Differential : public AUAV
 {
 public:
 	explicit AUAV_Differential(const I2CSPIDriverConfig &config);
 	~AUAV_Differential() = default;
 
+	void print_status() override;
+
 private:
 	void publish_pressure(const float pressure_p, const float temperature_c, const hrt_abstime timestamp_sample) override;
 	int64_t get_conversion_interval() const override;
 	calib_eeprom_addr_t get_calib_eeprom_addr() const override;
 	float process_pressure_dig(const float pressure_dig) const override;
+	int read_factory_data() override;
 
 	uORB::PublicationMulti<differential_pressure_s> _differential_pressure_pub{ORB_ID(differential_pressure)};
+	int32_t _cal_range{10};
 };