Environment - SHT2x

SHT2x series Temperature/Humidity

Plugin details

Type: Environment

Name: SHT2x

Status ESP32: COLLECTION F

Status ESP8266: COLLECTION F

GitHub: P122_SHT2x.ino

Maintainer: flashmark

Used libraries: I2C

Supported hardware

.

SHT21 sensor board

Note that on the internet there are many temperature/humidity sensor boards with I2C available. The board above mentions SI7021, SHT21 or HTU21. These are separate microchips, check what you have bought. The SI7021 and SHT21 are not compatible. This plugin only supprts the SHT21, SHT20 and SHT25.

Description

This plugin support the SHT2x series (SHT20, SHT21, SHT25) of temperature and humidity sensors. These sensors are connected by the I2C bus.

See datasheet: https://admin.sensirion.com/media/documents/120BBE4C/63500094/Sensirion_Datasheet_Humidity_Sensor_SHT21.pdf

Wiring

Connect the device to the I2C bus

Configuration

Device configuration

Name : A unique name should be entered here.

Enabled : The device can be disabled or enabled. When not enabled the device should not use any resources.

I2C Address : The Device address on the I2C bus. Default address is 0x40.

Force Slow I2C speed : Standard I2C setting to select a slow device. The SHT2x does not need slow I2C speed.

Resolution: Select one of the supported resolution settings of the device. See datasheet.

Data Acquisition

This group of settings are standard available configuration items.

  • Single event with all values: When this setting is enabled, all available values will be sent in a single event <TaskName>#All, with all values in order as arguments to the event.

  • Show derived values: When checked, the Devices overview page, and the /json endpoint (used for updating the Devices overview page) will include any Derived values as defined. See the TaskValueSetDerived and TaskValueSetPresentation commands.

  • Event & Log derived values: When checked, the Derived values will be generated as Events, to be handled in Rules, and sent to logging devices like the Syslog server and/or SD-card logging.

(The derived values options are only available if String variables feature is included in the build.)


  • Send to Controller: Select the Controller(s) to send the Values to, either on a TaskRun command applied to the task, or on an Interval time action.

Send to Controller is only visible when one or more Controllers are configured.

Depending on the controller capabilities, some configuration settings may be shown:

../_images/Task_config_page_Controllers_section.png

All configured Controllers are shown here, including the enabled or disabled state (multiple Controllers can be enabled, only a single MQTT Controller can be enabled at one time!).

For each controller the user can select wether the data should be sent on each Interval (or explicit TaskRun).

For the Domoticz controllers the value index (IDX) has to be configured.

For some controllers, like Home Assistant/openHAB, there are extra options available.

  • Group: This represents the group id to combine all values from multiple tasks into a single grouped-device during MQTT AutoDiscovery. Groups, by design, can span multiple ESPEasy devices, if desired, as long as the Task/Valuename combinations are unique. If a group should only combine Tasks from a single ESPEasy unit, the group id should be unique across multiple ESPEasy units. The group description, default Group <n>, can be adjusted in Home Assistant. If the Group value matches the current Unit nr, the Unit name, %sysname%, is used instead of Group <nr>.

  • Retained: For MQTT Controllers, this setting can be enabled to send the values for the current task with the Retain flag set. The Publish Retain flag in the Controller settings will override this by sending all task values with Retain flag enabled.

  • Send derived: This checkbox determines if any configured Derived values should also be sent to the controller (and included in the AutoDiscovery if that’s available and enabled).

  • Resend MQTT Discovery: When checked, will start a resend of the MQTT Discovery process for this task after a random delay, when Submit is clicked, so any changed settings will be updated in the MQTT broker. This setting is only available if the controller is enabled, the Auto Discovery feature is available and enabled for the controller. This setting is not stored.

Other controllers, like f.e. FHEM HTTP, do not support additional settings besides the checkbox to enable sending the data.


Change log

Changed in version 2.0: …

added Major overhaul for 2.0 release.

Added in version 1.0: …

added Initial release version.