SHT2x and compatible¶

group si7021

ESP-IDF driver for Si7013/Si7020/Si7021/HTU21D/SHT2x and compatible temperature and humidity sensors.

BSD Licensed as described in the file LICENSE

Defines

SI7021_I2C_ADDR¶: I2C address.

SI7021_MAX_HEATER_CURRENT¶: Maximum current of the heater for Si70xx.

Enums

enum si7021_device_id_t¶

Device model for Si70xx.

Values:

enumerator SI_MODEL_SI7013¶: Si7013.

enumerator SI_MODEL_SI7020¶: Si7020.

enumerator SI_MODEL_SI7021¶: Si7021.

enumerator SI_MODEL_SAMPLE¶: Engineering sample.

enumerator SI_MODEL_UNKNOWN¶: Unknown model.

enum si7021_resolution_t¶

Measurement resolution.

Values:

enumerator SI7021_RES_RH12_T14¶: Relative humidity: 12 bits, temperature: 14 bits.

enumerator SI7021_RES_RH08_T12¶: Relative humidity: 8 bits, temperature: 12 bits.

enumerator SI7021_RES_RH10_T13¶: Relative humidity: 10 bits, temperature: 13 bits.

enumerator SI7021_RES_RH11_T11¶: Relative humidity: 11 bits, temperature: 11 bits.

Functions

esp_err_t si7021_init_desc(i2c_dev_t *dev, i2c_port_t port, gpio_num_t sda_gpio, gpio_num_t scl_gpio)¶

Initialize device descriptor.

Parameters

dev – Device descriptor
port – I2C port
sda_gpio – SDA GPIO pin
scl_gpio – SCL GPIO pin

Returns

ESP_OK on success

esp_err_t si7021_free_desc(i2c_dev_t *dev)¶

Free device descriptor.

Parameters: dev – Device descriptor
Returns: ESP_OK on success

esp_err_t si7021_reset(i2c_dev_t *dev)¶

Reset device.

Parameters: dev – Device descriptor
Returns: ESP_OK on success

esp_err_t si7021_get_heater(i2c_dev_t *dev, bool *on)¶

Get heater state.

This function is supported by:

SI7013
SI7020
SI7021
SHT2x

Parameters

dev – Device descriptor
[out] on – true if heater enabled

Returns

ESP_OK on success

esp_err_t si7021_set_heater(i2c_dev_t *dev, bool on)¶

Switch heater on/off.

This function is supported by:

SI7013
SI7020
SI7021
SHT2x

Parameters

dev – Device descriptor
on – if true, heater will be enabled

Returns

ESP_OK on success

esp_err_t si7021_get_heater_current(i2c_dev_t *dev, uint8_t *level)¶

Get heater current.

This function is supported by:

SI7013
SI7020
SI7021

Parameters

dev – Device descriptor
[out] level – Heater current, see datasheet

Returns

ESP_OK on success

esp_err_t si7021_set_heater_current(i2c_dev_t *dev, uint8_t level)¶

Set heater current.

This function is supported by:

SI7013
SI7020
SI7021

Parameters

dev – Device descriptor
level – Heater current, see datasheet

Returns

ESP_OK on success

esp_err_t si7021_get_resolution(i2c_dev_t *dev, si7021_resolution_t *r)¶

Get measurement resolution.

Parameters

dev – Device descriptor
[out] r – Resolution

Returns

ESP_OK on success

esp_err_t si7021_set_resolution(i2c_dev_t *dev, si7021_resolution_t r)¶

Set measurement resolution.

Parameters

dev – Device descriptor
r – Resolution

Returns

ESP_OK on success

esp_err_t si7021_measure_temperature(i2c_dev_t *dev, float *t)¶

Measure temperature.

Parameters

dev – Device descriptor
[out] t – Temperature, deg. Celsius

Returns

ESP_OK on success

esp_err_t si7021_measure_humidity(i2c_dev_t *dev, float *rh)¶

Measure relative humidity.

Parameters

dev – Device descriptor
[out] rh – Relative humidity, %

Returns

ESP_OK on success

esp_err_t si7021_get_serial(i2c_dev_t *dev, uint64_t *serial, bool sht2x_mode)¶

Get serial number of device.

This function is supported by:

SI7013
SI7020
SI7021
SHT2x

Parameters

dev – Device descriptor
[out] serial – Serial no.
sht2x_mode – true for SHT2x devices

Returns

ESP_OK on success

esp_err_t si7021_get_device_id(i2c_dev_t *dev, si7021_device_id_t *id)¶

Get device model.

This function is supported by:

SI7013
SI7020
SI7021

Parameters

dev – Device descriptor
[out] id – Device model

Returns

ESP_OK on success