Python - CO2 Bricklet¶

Simple¶

Download (example_simple.py)

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#!/usr/bin/env python
# -*- coding: utf-8 -*-

HOST = "localhost"
PORT = 4223
UID = "XYZ" # Change XYZ to the UID of your CO2 Bricklet

from tinkerforge.ip_connection import IPConnection
from tinkerforge.bricklet_co2 import BrickletCO2

if __name__ == "__main__":
    ipcon = IPConnection() # Create IP connection
    co2 = BrickletCO2(UID, ipcon) # Create device object

    ipcon.connect(HOST, PORT) # Connect to brickd
    # Don't use device before ipcon is connected

    # Get current CO2 concentration
    co2_concentration = co2.get_co2_concentration()
    print("CO2 Concentration: " + str(co2_concentration) + " ppm")

    input("Press key to exit\n") # Use raw_input() in Python 2
    ipcon.disconnect()

Callback¶

Download (example_callback.py)

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#!/usr/bin/env python
# -*- coding: utf-8 -*-

HOST = "localhost"
PORT = 4223
UID = "XYZ" # Change XYZ to the UID of your CO2 Bricklet

from tinkerforge.ip_connection import IPConnection
from tinkerforge.bricklet_co2 import BrickletCO2

# Callback function for CO2 concentration callback
def cb_co2_concentration(co2_concentration):
    print("CO2 Concentration: " + str(co2_concentration) + " ppm")

if __name__ == "__main__":
    ipcon = IPConnection() # Create IP connection
    co2 = BrickletCO2(UID, ipcon) # Create device object

    ipcon.connect(HOST, PORT) # Connect to brickd
    # Don't use device before ipcon is connected

    # Register CO2 concentration callback to function cb_co2_concentration
    co2.register_callback(co2.CALLBACK_CO2_CONCENTRATION, cb_co2_concentration)

    # Set period for CO2 concentration callback to 1s (1000ms)
    # Note: The CO2 concentration callback is only called every second
    #       if the CO2 concentration has changed since the last call!
    co2.set_co2_concentration_callback_period(1000)

    input("Press key to exit\n") # Use raw_input() in Python 2
    ipcon.disconnect()

Threshold¶

Download (example_threshold.py)

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#!/usr/bin/env python
# -*- coding: utf-8 -*-

HOST = "localhost"
PORT = 4223
UID = "XYZ" # Change XYZ to the UID of your CO2 Bricklet

from tinkerforge.ip_connection import IPConnection
from tinkerforge.bricklet_co2 import BrickletCO2

# Callback function for CO2 concentration reached callback
def cb_co2_concentration_reached(co2_concentration):
    print("CO2 Concentration: " + str(co2_concentration) + " ppm")

if __name__ == "__main__":
    ipcon = IPConnection() # Create IP connection
    co2 = BrickletCO2(UID, ipcon) # Create device object

    ipcon.connect(HOST, PORT) # Connect to brickd
    # Don't use device before ipcon is connected

    # Get threshold callbacks with a debounce time of 10 seconds (10000ms)
    co2.set_debounce_period(10000)

    # Register CO2 concentration reached callback to function cb_co2_concentration_reached
    co2.register_callback(co2.CALLBACK_CO2_CONCENTRATION_REACHED,
                          cb_co2_concentration_reached)

    # Configure threshold for CO2 concentration "greater than 750 ppm"
    co2.set_co2_concentration_callback_threshold(">", 750, 0)

    input("Press key to exit\n") # Use raw_input() in Python 2
    ipcon.disconnect()

Basic Functions¶

BrickletCO2(uid, ipcon)¶

Parameters:	uid – Type: str ipcon – Type: IPConnection
Returns:	co2 – Type: BrickletCO2

Creates an object with the unique device ID uid:

co2 = BrickletCO2("YOUR_DEVICE_UID", ipcon)

This object can then be used after the IP Connection is connected.

BrickletCO2.get_co2_concentration()¶

Returns:	co2_concentration – Type: int, Unit: 1 ppm, Range: [0 to 10000]

Returns the measured CO2 concentration.

If you want to get the CO2 concentration periodically, it is recommended to use the CALLBACK_CO2_CONCENTRATION callback and set the period with set_co2_concentration_callback_period().

Advanced Functions¶

BrickletCO2.get_identity()¶

Return Object:

uid – Type: str, Length: up to 8 connected_uid – Type: str, Length: up to 8 position – Type: chr, Range: ["a" to "h", "z"] hardware_version – Type: [int, ...], Length: 3 0: major – Type: int, Range: [0 to 255] 1: minor – Type: int, Range: [0 to 255] 2: revision – Type: int, Range: [0 to 255] firmware_version – Type: [int, ...], Length: 3 0: major – Type: int, Range: [0 to 255] 1: minor – Type: int, Range: [0 to 255] 2: revision – Type: int, Range: [0 to 255] device_identifier – Type: int, Range: [0 to 216 - 1]

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', 'd', 'e', 'f', 'g' or 'h' (Bricklet Port). A Bricklet connected to an Isolator Bricklet is always at position 'z'.

The device identifier numbers can be found here. There is also a constant for the device identifier of this Bricklet.

Callback Configuration Functions¶

BrickletCO2.register_callback(callback_id, function)¶

Parameters:	callback_id – Type: int function – Type: callable
Returns:	None

Registers the given function with the given callback_id.

The available callback IDs with corresponding function signatures are listed below.

BrickletCO2.set_co2_concentration_callback_period(period)¶

Parameters:	period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
Returns:	None

Sets the period with which the CALLBACK_CO2_CONCENTRATION callback is triggered periodically. A value of 0 turns the callback off.

The CALLBACK_CO2_CONCENTRATION callback is only triggered if the CO2 concentration has changed since the last triggering.

BrickletCO2.get_co2_concentration_callback_period()¶

Returns:	period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0

Returns the period as set by set_co2_concentration_callback_period().

BrickletCO2.set_co2_concentration_callback_threshold(option, min, max)¶

Parameters:	option – Type: chr, Range: See constants, Default: "x" min – Type: int, Unit: 1 ppm, Range: [0 to 216 - 1], Default: 0 max – Type: int, Unit: 1 ppm, Range: [0 to 216 - 1], Default: 0
Returns:	None

Sets the thresholds for the CALLBACK_CO2_CONCENTRATION_REACHED callback.

The following options are possible:

Option	Description
'x'	Callback is turned off
'o'	Callback is triggered when the CO2 concentration is outside the min and max values
'i'	Callback is triggered when the CO2 concentration is inside the min and max values
'<'	Callback is triggered when the CO2 concentration is smaller than the min value (max is ignored)
'>'	Callback is triggered when the CO2 concentration is greater than the min value (max is ignored)

The following constants are available for this function:

For option:

• BrickletCO2.THRESHOLD_OPTION_OFF = "x"
• BrickletCO2.THRESHOLD_OPTION_OUTSIDE = "o"
• BrickletCO2.THRESHOLD_OPTION_INSIDE = "i"
• BrickletCO2.THRESHOLD_OPTION_SMALLER = "<"
• BrickletCO2.THRESHOLD_OPTION_GREATER = ">"

BrickletCO2.get_co2_concentration_callback_threshold()¶

Return Object:	option – Type: chr, Range: See constants, Default: "x" min – Type: int, Unit: 1 ppm, Range: [0 to 216 - 1], Default: 0 max – Type: int, Unit: 1 ppm, Range: [0 to 216 - 1], Default: 0

Returns the threshold as set by set_co2_concentration_callback_threshold().

The following constants are available for this function:

For option:

• BrickletCO2.THRESHOLD_OPTION_OFF = "x"
• BrickletCO2.THRESHOLD_OPTION_OUTSIDE = "o"
• BrickletCO2.THRESHOLD_OPTION_INSIDE = "i"
• BrickletCO2.THRESHOLD_OPTION_SMALLER = "<"
• BrickletCO2.THRESHOLD_OPTION_GREATER = ">"

BrickletCO2.set_debounce_period(debounce)¶

Parameters:	debounce – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 100
Returns:	None

Sets the period with which the threshold callbacks

• CALLBACK_CO2_CONCENTRATION_REACHED,

are triggered, if the thresholds

• set_co2_concentration_callback_threshold(),

keep being reached.

BrickletCO2.get_debounce_period()¶

Returns:	debounce – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 100

Returns the debounce period as set by set_debounce_period().

Callbacks¶

Callbacks can be registered to receive time critical or recurring data from the device. The registration is done with the register_callback() function of the device object. The first parameter is the callback ID and the second parameter the callback function:

def my_callback(param):
    print(param)

co2.register_callback(BrickletCO2.CALLBACK_EXAMPLE, my_callback)

The available constants with inherent number and type of parameters are described below.

BrickletCO2.CALLBACK_CO2_CONCENTRATION¶

Callback Parameters:	co2_concentration – Type: int, Unit: 1 ppm, Range: [0 to 10000]

This callback is triggered periodically with the period that is set by set_co2_concentration_callback_period(). The parameter is the CO2 concentration of the sensor.

The CALLBACK_CO2_CONCENTRATION callback is only triggered if the CO2 concentration has changed since the last triggering.

BrickletCO2.CALLBACK_CO2_CONCENTRATION_REACHED¶

Callback Parameters:	co2_concentration – Type: int, Unit: 1 ppm, Range: [0 to 10000]

This callback is triggered when the threshold as set by set_co2_concentration_callback_threshold() is reached. The parameter is the CO2 concentration.

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

Virtual Functions¶

Virtual functions don't communicate with the device itself, but operate only on the API bindings device object. They can be called without the corresponding IP Connection object being connected.

BrickletCO2.get_api_version()¶

Return Object:	api_version – Type: [int, ...], Length: 3 0: major – Type: int, Range: [0 to 255] 1: minor – Type: int, Range: [0 to 255] 2: revision – Type: int, Range: [0 to 255]

Returns the version of the API definition implemented by this API bindings. This is neither the release version of this API bindings nor does it tell you anything about the represented Brick or Bricklet.

BrickletCO2.get_response_expected(function_id)¶

Parameters:	function_id – Type: int, Range: See constants
Returns:	response_expected – Type: bool

Returns the response expected flag for the function specified by the function ID parameter. It is true if the function is expected to send a response, false otherwise.

For getter functions this is enabled by default and cannot be disabled, because those functions will always send a response. For callback configuration functions it is enabled by default too, but can be disabled by set_response_expected(). For setter functions it is disabled by default and can be enabled.

Enabling the response expected flag for a setter function allows to detect timeouts and other error conditions calls of this setter as well. The device will then send a response for this purpose. If this flag is disabled for a setter function then no response is sent and errors are silently ignored, because they cannot be detected.

The following constants are available for this function:

For function_id:

• BrickletCO2.FUNCTION_SET_CO2_CONCENTRATION_CALLBACK_PERIOD = 2
• BrickletCO2.FUNCTION_SET_CO2_CONCENTRATION_CALLBACK_THRESHOLD = 4
• BrickletCO2.FUNCTION_SET_DEBOUNCE_PERIOD = 6

BrickletCO2.set_response_expected(function_id, response_expected)¶

Parameters:	function_id – Type: int, Range: See constants response_expected – Type: bool
Returns:	None

Changes the response expected flag of the function specified by the function ID parameter. This flag can only be changed for setter (default value: false) and callback configuration functions (default value: true). For getter functions it is always enabled.

Enabling the response expected flag for a setter function allows to detect timeouts and other error conditions calls of this setter as well. The device will then send a response for this purpose. If this flag is disabled for a setter function then no response is sent and errors are silently ignored, because they cannot be detected.

The following constants are available for this function:

For function_id:

• BrickletCO2.FUNCTION_SET_CO2_CONCENTRATION_CALLBACK_PERIOD = 2
• BrickletCO2.FUNCTION_SET_CO2_CONCENTRATION_CALLBACK_THRESHOLD = 4
• BrickletCO2.FUNCTION_SET_DEBOUNCE_PERIOD = 6

BrickletCO2.set_response_expected_all(response_expected)¶

Parameters:	response_expected – Type: bool
Returns:	None

Changes the response expected flag for all setter and callback configuration functions of this device at once.

Constants¶

BrickletCO2.DEVICE_IDENTIFIER¶

This constant is used to identify a CO2 Bricklet.

The get_identity() function and the IPConnection.CALLBACK_ENUMERATE callback of the IP Connection have a device_identifier parameter to specify the Brick's or Bricklet's type.

BrickletCO2.DEVICE_DISPLAY_NAME¶

This constant represents the human readable name of a CO2 Bricklet.