Generic - Dummy Device¶

Plugin details¶

Type: Generic

Name: Dummy Device

Status: NORMAL CLIMATE

Maintainer: .

Used libraries: .

Description¶

You can use a special dummy device within ESP Easy to provide additional features to the rules engine. A dummy device contains 1 (Single) to 4 (Quad) sensor values, depending on the Output Data Type selected, that can be used as variables to store custom numerical data. (floating point values, like 123.50)

The dummy device can be used like any other sensor to send it’s data to a Controller. But this is not mandatory if you only want to use it within your own rules section.

Dummy tasks can be used like temporary variables to store data. One nice benefit is that these task values of Dummy tasks are also kept in RTC memory. So these may survive a reboot, as long as the ESP remains powered.

Storing Values¶

Typically, one can only interact with a Dummy task via the TaskValueSet command:

TaskValueSet <task nr/task name>,<value nr/value name>,<value|formula>

A few examples:

You run your dummy device from task number 3 and the first value should contain something calculated from a temperature sensor labeled “Outdoor”:

TaskValueSet 3,1,[Outdoor#Temperature]-10

To make the variable to set and the task number independent, the name of the task and/or value can be used instead of the numbers.

So for a Dummy device named Dummy, Output Data Type set to Temp / Hum, and Values named Temp and Hum, setting the Temperature value:

TaskValueSet,Dummy,temp,[Outdoor#Temperature]-10

(task name and value name are not case sensitive)

Note: You can use multiple Dummy devices if needed!

Output Configuration¶

A Dummy can be configured to output a specific data type. Especially Domoticz controllers require some specific data type to properly handle specific devices which output several units of measure.

For example “Temp / Hum / Baro” are obviously intended to mimic the well known Bosch BME280 sensor.

Basic data types like “Single”, “Dual”, “Triple”, “Quad” are intended to set resp. 1 … 4 float values.

Extended Output Data Types¶

Added: 2023/04/15

Storing data in float values may result in loss of decimals. A float can only store upto 22 bit if numerical information.

For example the “UnixTime” (number of seconds since 1970/01/01) cannot accurately be stored in a float.

To overcome these issues, a number of integer types are added:

Int32 - Integer value ranging from -2147483648 … 2147483647 (-1 * 2^31 … (2^31 - 1))
UInt32 - Integer value ranging from 0 … 4294967295 (2^32 - 1)
Int64 - Integer value ranging from -1 * 2^63 … (2^63 - 1)
UInt64 - Integer value ranging from 0 … (2^64 - 1)
Double - “Double” Floating point value capable of storing 52 bit of numerical information.

The offered selection also shows the number of task values being configured. For example Int32 (3x) implies 3 task values of type Int32.

Since 64 bit ints and double need 8 bytes, where the other types only require 4 bytes. Therefore the maximum number of those task values possible is half that of the other types.

Storing data in 64 bit ints may not allow to store the full range as one may expect to store based on the integer types. The TaskValueSet command internally processes data as double, thus limiting the maximum range of these integer values to -9007199254740992 … 9007199254740991.

One can store larger values in these 64 bit int types, but this will result in loss of bits.

For example:

9007199254740993 cannot be stored in such a data type as it will be rounded back to 9007199254740992 when used.
1234567890123456789 will be read back as 1234567890123456768, which may seem correct at first sight, but the last few digits are wrong.

Storing large values in other integer types, like UInt32, will be clipped to the maximum value that can be handled by that type.

For example:

1234567890123456789 stored in an UInt32 will be read back as 4294967295
-1 stored in an UInt32 will be read back as 4294967295
1234567890123456789 stored in an Int32 will be read back as 2147483647
-1 stored in an Int32 will be read back as -2147483648

Data Acquisition¶

In ESPEasy, a task can be triggered to yield some new sample data. For other plugins, this means the sensor is read and when successful there is some new data to process.

However, since the Dummy device doesn’t interact with a device, it will always be “successful” on a task run.

One may set the “Interval” to periodically trigger a new task run, or trigger a task run via the command TaskRun.

Note

The command TaskValueSetAndRun is a combination of TaskValueSet and TaskRun.

On a task run, there will be one or more events fired (depending on whether or not “Single event with all values” is checked). And all connected controllers of that task will be handed over the values present in the task values.

Especially Domoticz controllers are very specific to the output data type.

Change log¶

Changed in version 2.0: …

improved 2023-04-15 Add more types of task values, like (u)int32, (u)int64 and double.

improved 2021-08-18 Make Interval optional, so no interval (0) can be used.

added Major overhaul for 2.0 release.

Added in version 1.0: …

added Initial release version.