drivers: sensor: explorir_m: add calibration (6c627df6) · Commits · Wenxi XU / zephyr

drivers/sensor/explorir_m/explorir_m.c

+50 −0

Changes for drivers/sensor/explorir_m/explorir_m.c: 50 added lines, 0 removed lines.
Original line number	Diff line number	Diff line
		@@ -26,6 +26,7 @@ LOG_MODULE_REGISTER(explorir_m_sensor, CONFIG_SENSOR_LOG_LEVEL);
		#define EXPLORIR_M_SET_FILTER_CHAR 'A'
		#define EXPLORIR_M_GET_FILTER_CHAR 'a'
		#define EXPLORIR_M_MODE_CHAR 'K'
		#define EXPLORIR_M_ZERO_POINT_KNOWN_CHAR 'X'
		#define EXPLORIR_M_CO2_FILTERED_CHAR 'Z'
		#define EXPLORIR_M_SCALING_CHAR '.'
		#define EXPLORIR_M_NOT_RECOGNISED_CHAR '?'
		@@ -130,6 +131,7 @@ static int explorir_m_buffer_process(struct explorir_m_data *data, char type,
		switch (type) {
		case EXPLORIR_M_SET_FILTER_CHAR:
		case EXPLORIR_M_MODE_CHAR:
		case EXPLORIR_M_ZERO_POINT_KNOWN_CHAR:
		break;

		case EXPLORIR_M_CO2_FILTERED_CHAR:
		@@ -251,6 +253,52 @@ static int explorir_m_uart_transceive(const struct device *dev, char type, struc
		return rc;
		}

		/*
		* This calibrate function uses a known gas concentration [ppm] via val->val1 to calibrate.
		* Calibration should be done when temperature is stabile and gas is fully diffused into the sensor.
		*/
		static int explorir_m_calibrate(const struct device dev, struct sensor_value val)
		{
		struct explorir_m_data *data = dev->data;
		struct sensor_value original;
		struct sensor_value tmp;
		int restore_rc;
		int rc;

		/* Prevent sensor interaction while using calibration filter value */
		k_mutex_lock(&data->uart_mutex, K_FOREVER);

		rc = explorir_m_uart_transceive(dev, EXPLORIR_M_GET_FILTER_CHAR, &original,
		EXPLORIR_M_SET_NONE);
		if (rc != 0) {
		goto unlock;
		}

		/*
		* From datasheet section "Zero point setting":
		* To improve zeroing accuracy, the recommended digital filter setting is 32.
		*/
		tmp.val1 = 32;
		rc = explorir_m_uart_transceive(dev, EXPLORIR_M_SET_FILTER_CHAR, &tmp,
		EXPLORIR_M_SET_VAL_ONE);
		if (rc == 0) {
		tmp.val1 = val->val1 / data->filtered;
		rc = explorir_m_uart_transceive(dev, EXPLORIR_M_ZERO_POINT_KNOWN_CHAR, &tmp,
		EXPLORIR_M_SET_VAL_ONE);
		}

		restore_rc = explorir_m_uart_transceive(dev, EXPLORIR_M_SET_FILTER_CHAR, &original,
		EXPLORIR_M_SET_VAL_ONE);
		if (restore_rc != 0) {
		LOG_ERR("Could not restore filter value");
		}

		unlock:
		k_mutex_unlock(&data->uart_mutex);

		return rc != 0 ? rc : restore_rc;
		}

		static int explorir_m_attr_get(const struct device *dev, enum sensor_channel chan,
		enum sensor_attribute attr, struct sensor_value *val)
		{
		@@ -275,6 +323,8 @@ static int explorir_m_attr_set(const struct device *dev, enum sensor_channel cha
		}

		switch (attr) {
		case SENSOR_ATTR_CALIBRATION:
		return explorir_m_calibrate(dev, (struct sensor_value *)val);
		case SENSOR_ATTR_EXPLORIR_M_FILTER:
		if (val->val1 < 0 \|\| val->val1 > 255) {
		return -ERANGE;

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