TCP/IP - Gas Detector Bricklet – Tinkerforge

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# TCP/IP - Gas Detector Bricklet

Note

This Bricklet is currently in the prototype stage and the software/hardware as well as the documentation is in an incomplete state.

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

## API

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

### Basic Functions

`BrickletGasDetector.``get_value`

  Function ID: | 1
  Request: | empty payload

  Response:

  - value -- uint16

  Returns a value between 0 and 4095.

  See here for more information about the measurements.

  If you want to get the value periodically, it is recommended to use the callback `CALLBACK_VALUE` and set the period with `set_value_callback_period`.

### Advanced Functions

`BrickletGasDetector.``set_moving_average`

  Function ID: | 8

  Request:

  - average -- uint8

  Response: | no response

  Sets the length of a moving averaging for the measured value.

  Setting the length to 1 will turn the averaging off. With less averaging, there is more noise on the data.

  The range for the averaging is 1-100.

  The default value is 100.

`BrickletGasDetector.``get_moving_average`

  Function ID: | 9
  Request: | empty payload

  Response:

  - average -- uint8

  Returns the length moving average as set by `set_moving_average`.

`BrickletGasDetector.``set_detector_type`

  Function ID: | 10

  Request:

  - detector_type -- uint8

  Response: | no response

  Sets the detector type.

  The following types are currently supported.

  - Type 0: MQ2 and MQ5
  - Type 1: MQ3

  The detector type is written to the EEPROM of the Bricklet, so it only has to be set once.

  You can use the Brick Viewer to set the detector type, so you likely don't need to use this function in your source code.

  The default detector type is 0.

`BrickletGasDetector.``get_detector_type`

  Function ID: | 11
  Request: | empty payload

  Response:

  - detector_type -- uint8

  Returns the detector type as set by `set_detector_type`.

`BrickletGasDetector.``heater_on`

  Function ID: | 12
  Request: | empty payload
  Response: | no response

  Turns the internal heater on.

`BrickletGasDetector.``heater_off`

  Function ID: | 13
  Request: | empty payload
  Response: | no response

  Turns the internal heater off.

`BrickletGasDetector.``is_heater_on`

  Function ID: | 14
  Request: | empty payload

  Response:

  - heater -- bool

  Returns true if the heater is on, false otherwise.

`BrickletGasDetector.``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

`BrickletGasDetector.``set_value_callback_period`

  Function ID: | 2

  Request:

  - period -- uint32

  Response: | no response

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

  `CALLBACK_VALUE` is only triggered if the value value has changed since the last triggering.

  The default value is 0.

`BrickletGasDetector.``get_value_callback_period`

  Function ID: | 3
  Request: | empty payload

  Response:

  - period -- uint32

  Returns the period as set by `set_value_callback_period`.

`BrickletGasDetector.``set_value_callback_threshold`

  Function ID: | 4

  Request:

  - option -- char
  - min -- uint16
  - max -- uint16

  Response: | no response

  Sets the thresholds for the `CALLBACK_VALUE_REACHED` callback.

  The following options are possible:

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

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

`BrickletGasDetector.``get_value_callback_threshold`

  Function ID: | 5
  Request: | empty payload

  Response:

  - option -- char
  - min -- uint16
  - max -- uint16

  Returns the threshold as set by `set_value_callback_threshold`.

`BrickletGasDetector.``set_debounce_period`

  Function ID: | 6

  Request:

  - debounce -- uint32

  Response: | no response

  Sets the period in ms with which the threshold callback

  - `CALLBACK_VALUE_REACHED`

  is triggered, if the threshold

  - `set_value_callback_threshold`

  keeps being reached.

  The default value is 100.

`BrickletGasDetector.``get_debounce_period`

  Function ID: | 7
  Request: | empty payload

  Response:

  - debounce -- uint32

  Returns the debounce period as set by `set_debounce_period`.

### Callbacks

`BrickletGasDetector.``CALLBACK_VALUE`

  Function ID: | 15

  Response:

  - value -- uint16

  This callback is triggered periodically with the period that is set by `set_value_callback_period`. The response value is the value value of the sensor.

  `CALLBACK_VALUE` is only triggered if the value has changed since the last triggering.

`BrickletGasDetector.``CALLBACK_VALUE_REACHED`

  Function ID: | 16

  Response:

  - value -- uint16

  This callback is triggered when the threshold as set by `set_value_callback_threshold` is reached. The response value is the value of the detector.

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

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