TCP/IP - Barometer Bricklet

This is the description of the TCP/IP protocol for the Barometer Bricklet. General information and technical specifications for the Barometer Bricklet are summarized in its hardware description.

API

A general description of the TCP/IP protocol structure can be found here.

Basic Functions

BrickletBarometer.get_air_pressure
Function ID:

1

Request:

empty payload

Response:
  • air_pressure -- int32

Returns the air pressure of the air pressure sensor. The value has a range of 10000 to 1200000 and is given in mbar/1000, i.e. a value of 1001092 means that an air pressure of 1001.092 mbar is measured.

If you want to get the air pressure periodically, it is recommended to use the CALLBACK_AIR_PRESSURE callback and set the period with set_air_pressure_callback_period.

BrickletBarometer.get_altitude
Function ID:

2

Request:

empty payload

Response:
  • altitude -- int32

Returns the relative altitude of the air pressure sensor. The value is given in cm and is calculated based on the difference between the current air pressure and the reference air pressure that can be set with set_reference_air_pressure.

If you want to get the altitude periodically, it is recommended to use the CALLBACK_ALTITUDE callback and set the period with set_altitude_callback_period.

BrickletBarometer.set_reference_air_pressure
Function ID:

13

Request:
  • air_pressure -- int32
Response:

no response

Sets the reference air pressure in mbar/1000 for the altitude calculation. Valid values are between 10000 and 1200000. Setting the reference to the current air pressure results in a calculated altitude of 0cm. Passing 0 is a shortcut for passing the current air pressure as reference.

Well known reference values are the Q codes QNH and QFE used in aviation.

The default value is 1013.25mbar.

BrickletBarometer.get_reference_air_pressure
Function ID:

19

Request:

empty payload

Response:
  • air_pressure -- int32

Returns the reference air pressure as set by set_reference_air_pressure.

Advanced Functions

BrickletBarometer.get_chip_temperature
Function ID:

14

Request:

empty payload

Response:
  • temperature -- int16

Returns the temperature of the air pressure sensor. The value has a range of -4000 to 8500 and is given in °C/100, i.e. a value of 2007 means that a temperature of 20.07 °C is measured.

This temperature is used internally for temperature compensation of the air pressure measurement. It is not as accurate as the temperature measured by the Temperature Bricklet or the Temperature IR Bricklet.

BrickletBarometer.set_averaging
Function ID:

20

Request:
  • moving_average_pressure -- uint8
  • average_pressure -- uint8
  • average_temperature -- uint8
Response:

no response

Sets the different averaging parameters. It is possible to set the length of a normal averaging for the temperature and pressure, as well as an additional length of a moving average for the pressure. The moving average is calculated from the normal averages. There is no moving average for the temperature.

The maximum length for the pressure average is 10, for the temperature average is 255 and for the moving average is 25.

Setting the all three parameters to 0 will turn the averaging completely off. If the averaging is off, there is lots of noise on the data, but the data is without delay. Thus we recommend to turn the averaging off if the Barometer Bricklet data is to be used for sensor fusion with other sensors.

The default values are 10 for the normal averages and 25 for the moving average.

New in version 2.0.1 (Plugin).

BrickletBarometer.get_averaging
Function ID:

21

Request:

empty payload

Response:
  • moving_average_pressure -- uint8
  • average_pressure -- uint8
  • average_temperature -- uint8

Returns the averaging configuration as set by set_averaging.

New in version 2.0.1 (Plugin).

BrickletBarometer.get_identity
Function ID:

255

Request:

empty payload

Response:
  • uid -- char[8]
  • connected_uid -- char[8]
  • position -- char
  • hardware_version -- uint8[3]
  • firmware_version -- uint8[3]
  • device_identifier -- uint16

Returns the UID, the UID where the Bricklet is connected to, the position, the hardware and firmware version as well as the device identifier.

The position can be 'a', 'b', 'c' or 'd'.

The device identifier numbers can be found here

Callback Configuration Functions

BrickletBarometer.set_air_pressure_callback_period
Function ID:

3

Request:
  • period -- uint32
Response:

no response

Sets the period in ms with which the CALLBACK_AIR_PRESSURE callback is triggered periodically. A value of 0 turns the callback off.

The CALLBACK_AIR_PRESSURE callback is only triggered if the air pressure has changed since the last triggering.

The default value is 0.

BrickletBarometer.get_air_pressure_callback_period
Function ID:

4

Request:

empty payload

Response:
  • period -- uint32

Returns the period as set by set_air_pressure_callback_period.

BrickletBarometer.set_altitude_callback_period
Function ID:

5

Request:
  • period -- uint32
Response:

no response

Sets the period in ms with which the CALLBACK_ALTITUDE callback is triggered periodically. A value of 0 turns the callback off.

The CALLBACK_ALTITUDE callback is only triggered if the altitude has changed since the last triggering.

The default value is 0.

BrickletBarometer.get_altitude_callback_period
Function ID:

6

Request:

empty payload

Response:
  • period -- uint32

Returns the period as set by set_altitude_callback_period.

BrickletBarometer.set_air_pressure_callback_threshold
Function ID:

7

Request:
  • option -- char
  • min -- int32
  • max -- int32
Response:

no response

Sets the thresholds for the CALLBACK_AIR_PRESSURE_REACHED callback.

The following options are possible:

Option Description
'x' Callback is turned off
'o' Callback is triggered when the air pressure is outside the min and max values
'i' Callback is triggered when the air pressure is inside the min and max values
'<' Callback is triggered when the air pressure is smaller than the min value (max is ignored)
'>' Callback is triggered when the air pressure is greater than the min value (max is ignored)

The default value is ('x', 0, 0).

The following meanings are defined for the parameters of this function:

  • x: off, for option
  • o: outside, for option
  • i: inside, for option
  • <: smaller, for option
  • >: greater, for option
BrickletBarometer.get_air_pressure_callback_threshold
Function ID:

8

Request:

empty payload

Response:
  • option -- char
  • min -- int32
  • max -- int32

Returns the threshold as set by set_air_pressure_callback_threshold.

The following meanings are defined for the parameters of this function:

  • x: off, for option
  • o: outside, for option
  • i: inside, for option
  • <: smaller, for option
  • >: greater, for option
BrickletBarometer.set_altitude_callback_threshold
Function ID:

9

Request:
  • option -- char
  • min -- int32
  • max -- int32
Response:

no response

Sets the thresholds for the CALLBACK_ALTITUDE_REACHED callback.

The following options are possible:

Option Description
'x' Callback is turned off
'o' Callback is triggered when the altitude is outside the min and max values
'i' Callback is triggered when the altitude is inside the min and max values
'<' Callback is triggered when the altitude is smaller than the min value (max is ignored)
'>' Callback is triggered when the altitude is greater than the min value (max is ignored)

The default value is ('x', 0, 0).

The following meanings are defined for the parameters of this function:

  • x: off, for option
  • o: outside, for option
  • i: inside, for option
  • <: smaller, for option
  • >: greater, for option
BrickletBarometer.get_altitude_callback_threshold
Function ID:

10

Request:

empty payload

Response:
  • option -- char
  • min -- int32
  • max -- int32

Returns the threshold as set by set_altitude_callback_threshold.

The following meanings are defined for the parameters of this function:

  • x: off, for option
  • o: outside, for option
  • i: inside, for option
  • <: smaller, for option
  • >: greater, for option
BrickletBarometer.set_debounce_period
Function ID:

11

Request:
  • debounce -- uint32
Response:

no response

Sets the period in ms with which the threshold callbacks

are triggered, if the thresholds

keep being reached.

The default value is 100.

BrickletBarometer.get_debounce_period
Function ID:

12

Request:

empty payload

Response:
  • debounce -- uint32

Returns the debounce period as set by set_debounce_period.

Callbacks

BrickletBarometer.CALLBACK_AIR_PRESSURE
Function ID:

15

Response:
  • air_pressure -- int32

This callback is triggered periodically with the period that is set by set_air_pressure_callback_period. The response value is the air pressure of the air pressure sensor.

The CALLBACK_AIR_PRESSURE callback is only triggered if the air pressure has changed since the last triggering.

BrickletBarometer.CALLBACK_ALTITUDE
Function ID:

16

Response:
  • altitude -- int32

This callback is triggered periodically with the period that is set by set_altitude_callback_period. The response value is the altitude of the air pressure sensor.

The CALLBACK_ALTITUDE callback is only triggered if the altitude has changed since the last triggering.

BrickletBarometer.CALLBACK_AIR_PRESSURE_REACHED
Function ID:

17

Response:
  • air_pressure -- int32

This callback is triggered when the threshold as set by set_air_pressure_callback_threshold is reached. The response value is the air pressure of the air pressure sensor.

If the threshold keeps being reached, the callback is triggered periodically with the period as set by set_debounce_period.

BrickletBarometer.CALLBACK_ALTITUDE_REACHED
Function ID:

18

Response:
  • altitude -- int32

This callback is triggered when the threshold as set by set_altitude_callback_threshold is reached. The response value is the altitude of the air pressure sensor.

If the threshold keeps being reached, the callback is triggered periodically with the period as set by set_debounce_period.